°cDegrees Centigrade
°FDegrees Fahrenheit



AAAluminum Association
AAMAWhile many will associate the AAMA as an acronym for American Association of Medical Assistants which provides medical assistant professionals with education, training and certifications, in the construction trade, AAMA stands for “American Architectural Manufacturers Association”; an organization that brings codes, test, standards and certification to the glass, glazing, storefront, window, door and skylight industry.
AAMA GoldAn AAMA certification program relating to testing in areas of air leakage, water penetration, structural performance, operating forces, forced entry resistance and life cycle durability in doors and windows.
AAMA SilverAn AAMA certification program relating to testing in areas relating to the thermal performance only.
AbsorbedThe collection of dissolved resin in condensed form in and on the anodic film.
AbsorptanceEnergy that is not transmitted through the glass or reflected off its surfaces is absorbed. IE; ratio of radiant energy absorbed compared to the total radiant energy. Note that once glass has absorbed radiant energy, the energy is transformed into heat, raising the glass temperature.
Access DoorService access door. Also a door in an area where sliding wall panels stack.
AccessibleDesigns for approaching areas inside or outside facilities.
Accessory GrooveA shape included on a fenestration product frame that is designed to mate with installation accessories.
AccreditationCertification of competence in a specified subject or areas of expertise, and of the integrity of an agency, firm, group, or person, awarded by a duly recognized and respected accrediting organization.
ACDDAnnual Cooling Degree Days
AcousticsA science that deals with the production, control, transmission, reception, and effects of sound
AcrylicDerived from acrylic acid. Known by trade names Plexiglas, Acrylite, Lucite, and Perspex among several others. Often used in sheet form as a lightweight or shatter-resistant alternative to glass.
Acrylic Paint or LatexA paint composed of acrylic resins, thinned with water.
ActivatorA material component that, when added to the base compound of a multi-component system, will cause or accelerate the curing process.
Active Door (Or Leaf)First operating door in a door pair. The active door is usually equipped with the lock cylinder.
Active Multipoint Point Locking HardwareA lock with at least two locking points other than the latch and center deadbolt.
Active PanelIn paired or dual window or door units, this is the main or first operating panel. The secondary panel is called the passive panel.
Active Solar Heat GainSolar heat that passes through a material and is mechanically captured.
AddendumWritten or graphic instructions issued prior to the execution of the Contract which modify or interpret the bidding documents, including Drawings and Specifications, by additions, deletions, clarifications or corrections. Addenda will become part of the Contract Documents when the Construction Contract is executed.
AdditionThe construction of a room that is attached to an existing structure.
AdhesionThat property of a coating or sealant which measures its ability to stick or attach/bond to the applied surface.
Adhesion Peel TestThe bond separation test. The material is pulled away from the surface at a certain angle (90° or 180° angle to the plane to which it is adhered. Values are expressed in pounds/inch width.
AdhesiveA sticky substance to bond one material to another.  Use the term “Adhere” instead of “Glue.”  Do not use “Glue,” “Cement,” or Mastic.
Adhesive FailureFailure of the bond between the sealant and the surface to which it is in contact.
Adhesive MaterialThe seal between a material and the surface to which it adheres.
AdjustableA window, door or skylight that can be tweaked into true or square to become for effective.
Advertisement for BidsPublished public notice soliciting bids for a construction project. Most frequently used to conform to legal requirements pertaining to projects to be constructed under public authority, and usually published on newspapers of general circulation in those districts from which the public funds are derived.
AECAluminum Extruders Council
Aeroelastic (Dynamic) ModelThis is a building model that is constructed to deflect and oscillate in response to fluctuating air flow induced forces. Strain gauges mounted on elastic elements and accelerometers attached to the frame of this type of model are used to measure peak and mean values of fluctuating moments, deflections and accelerations for the overall building. While this type of model is not primarily used for curtain walls, curtain wall performance can be affected by in-plane and out-of-plane racking of the curtain wall system as the building deflects. Peak deflections obtained from the aeroelastic model tests can be used to estimate maximum deflections of the system elements.
AerogelAerogel was first created in 1931. It is a synthetic porous ultralight material. It has an extremely low density[2] and low thermal conductivity. Nicknames include frozen smoke or blue smoke.
Aerosol Foam SealantA sealant that expands in volume as it is dispensed from a container, using propellant under pressure, to form a rigid or semi-rigid cellular mass.
AestheticsThe science and philosophy of beauty.
AFUEAnnual Fuel Utilization Efficiency
Aging in PlaceThe ability to live in one’s own home and community safely, independently, and comfortably, regardless of age, income, or ability level
AgreementOn a construction project, the document stating the essential terms of the Construction Contract which incorporates by reference the other Contract Documents. The document setting forth the terms of the Contract between the Architect and a consultant.
AHDDAnnual Heating Degree Days
AIAAmerican Institute of Architects
Air And Water Barrier (Air/Water Barrier)Wall system layer(s) that limits the transfer of liquid water and air through the system. The barrier shall be adequate to withstand design wind load requirements, either independently or through a backup system. The terms “air and water barrier” and/or “air/water barrier” may also indicate a material that is also a vapor retarder.
Air BarrierThe assembly of materials used in building construction to cut down on the passage of air in and out of the building.
Air Barrier Foam SealantAlso referred to as expanding foam. An aerosol foam product dispensed as a bead into the air gap area around the fenestration perimeter to reduce the infiltration or ex-filtration of air between the fenestration product and the rough opening.
Air InfiltrationUnintentional or accidental introduction of outside air into a building, typically through cracks in the building envelope and through use of doors, windows and other openings. Also caused by low quality windows and doors. As a low air infiltration number is best, a blower door test us often used to zero in on problem areas of infiltration.
Air LeakageLeakage through the window assembly itself. It is indicated by an air leakage rating (AL) expressed as the equivalent cubic feet of air passing through a square foot of window area.
Air Leakage RateThe volume of air flowing per unit of time through leakage paths in the closed window product under specified temperature and pressure conditions on both sides of the window.
Air Leakage ResistanceThe amount of air leaking through cracks in walls, windows, and doors.
Air MassThe ratio of the mass of atmosphere along the actual observer-to-sun line to the mass that would exist if the observer was at sea level, a standard barometric pressure and if the sun was directly overhead (at the zenith).
Air PocketsBubbles of air entrapped within a sealant, or between two adjacent beads of sealant applied successively in a joint.
Air SealA continuous seal put into the air gap area around the interior side, exterior side or both sides of the fenestration perimeter to restrict infiltration or exfiltration of air past the fenestration product.
Airblast Over­PressureThe variation of air pressure caused by a blast event relative to ambient pressure conditions.
Air-leakage RatingA measure of the rate of air-leakage around a window, door, or skylight in the presence of a specific pressure difference. It is expressed in units of cubic feet per minute per square foot of frame area (cfm/sq ft). Formerly expressed as cubic feet per minute per foot of window perimeter length (cfm/ft) but not now in use. The lower a window’s air-leakage rating, the better its airtightness.
Airlock StripThe weatherstripping attached to the edges of each wing of a revolving door.
AirspaceThe physical distance between the two sheets of glass in double insulated glass unit or both of the two spaces in a triple insulated glass unit.
AirspacerThe physical product that separates the two or more lites of glass in an insulating glass unit. The material may be aluminum, stainless steel, silicone, plastic to name a few. Also available in several colors. Often times manufactures place a manufacturing stamp on the spacer component as a permanent reference for manufacturing date and time.
ALCAir Leakage Control
AlderA widely distributed tree of the birch family that has toothed leaves and bears male catkins and woody female cones.
Alkyd (Paint)A paint composed of a chemically synthesized, alkyd derived base, thinned with mineral spirits. The current version of “oil” based paints.
All-Glass DoorSee GLASS DOOR.
AlterationA planned or executed change to an existing building, short of complete demolition of the building.
AlternateMechanism used in Bid Documents to seek separate bids for a different design than the “Base Bid” design.  May be “Additive” or “Deductive” alternates.
Aluminum SpacerUeog = 0.223 + 0.842Ucog – 0.153Ucog2
Aluminum WindowsWindows with the frame and sash made out of aluminum. Aluminum window frames are light, strong, durable, and easily extruded into the complex shapes required for window parts. The biggest disadvantage of aluminum as a window frame material is its obviously high thermal conductance.
Ambient Temperature/ConditionsThe temperature or conditions (humidity, air velocity, light exposure, etc.) which surround or encompass the area of concern, i.e., a test specimen, framing member, etc.
AmplitudeThe difference between the maximum and minimum pressure that is developed in a sound pulse.
AnchorAny device used to secure a building part or component to adjoining construction or a supporting member. See also and .
Anchor PointA line (or point) of reference on fenestration products and/or the building where attachment is made.
AnchorageThe attachment of the individual products or mulled fenestration assembly to the rough opening with regard to transferring load.
Angular DistortionThe rotation of the exterior face of the framing member from its nominal position. Normally this is caused by thermal stresses during pouring and curing, improper handling or uneven glazing pressures.
Annealed GlassStandard sheet of float glass which has not been heat-treated. Further processing is required to transform annealed glass into safety glass.
AnnealingHeating above the critical or recrystallization temperature, then controlled cooling of metal, glass, or other materials to eliminate the effects of cold-working, relieve internal stresses, or improve strength, ductility, or other properties.
Annealing LehrAn on-line, controlled heating/cooling apparatus located after the tin bath and before the cooling conveyor of a float glass production line. Its purpose is to relieve induced stress from the flat glass product to allow normal cold end processing.
Annual EnergyThe composite fuel and electric energy at the building site boundary for heating, cooling, and lighting the building, including pump energy and fan energy.
Annual LoadsThe separate energy requirements for each of the three factors heating, cooling, and lighting.
Anodic FinishesAnodic coatings are composed of aluminum oxide and are an integral part of the aluminum substrate. Careful control is permitted by the electrolytic anodizing process, and it provides substantial improvement over the natural oxide film due to greater thickness, density, and hardness of these factory-produced finishes. They may be clear (natural) or colored. Color is electrolytically deposited or integral. Pre-anodic chemical treatments clean and prepare the aluminum for the anodic finish. The Aluminum Association classifies architectural anodic coatings depending on coating thickness and recommended use. Further detailed information and specifications on anodic finishes are available from the Aluminum Association and the American Architectural Manufacturers Association.
AnodizeTo give an aluminum oxide coating by electrolytic action.
Anodizing AluminumAluminum that is treated by electrolysis to develop a finished surface (an extremely hard, noncorrosive oxide film). The electrochemical process produces an anodic coating by converting aluminum into aluminum oxide by electrolytic action. The resulting finish may be either clear or colored, and is an integral part of the aluminum.
ANSIAn acronym for the American National Standards Institute, which is an non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organization also coordinates U.S. standards with international standards so that American products can be used worldwide.
Anti-Reflective CoatingA transparent coating, typically 150 nm thick, which reduces surface reflectance by using destructive interference between light reflected at the substrate surface and light reflected at the coating surface.
Anti-Walk BlocksElastomeric blocks that limit glass from moving lateral in the glazing rabbet which may result from thermal, seismic, wind load effects, building movement, and other forces that may apply.
Application LifeThe period of time during which a sealant, after being mixed with a catalyst or exposed to the atmosphere, remains suitable for application; also referred to as work life, or pot life.
Applied CoatingThe process of applying an organic coating using various application methods on a prepared surface and curing it into a continuous film.
Applied FilmsWindow film often is applied to the room-side glass surface of windows. Since window film absorbs the portion of solar heat that it does not reflect or transmit, it increases the glass temperature and may cause thermal stress on the glass or insulated glazing seals, particularly on sunny but cold days. Before installing window film, be sure to check whether this interferes with the warranty conditions for your windows and whether self-installation would meet the window film’s warranty requirements
Applied FlangeA separate flange that may be added to or removed from the window or door frame. (a.k.a. field-applied/mechanically attached, non-integral flange)
Applied MuntinA profile member applied to the exterior or interior of a lite of glass to simulate individual glass lites. The members may be tape applied, sandwiched with the glass and glazed in, or designed to be removable.
Applied StopSurface mounted stop attached to a cased opening frame.
ApprovalThe term “approved,” where used in conjunction with the Architect’s action on the Contractor’s submittal, applications, and requests, is limited to the Architect’s duties and responsibilities as stated in General and Supplementary Conditions.
ApronA molding applied horizontally to the wall, directly below the window sill. It is used to hide the rough edge of the drywall or plaster below the window framing
Arch or Arch-top WindowA four sided unit with a curve at the top
ArchitecturalConventional aluminum oxide coatings which are formed in sulfuric acid based
Architectural Color Anodic FinishesClear aluminum oxide coatings that are dyed to produce a range of colors including gold, red, yellow, blue, turquoise and black. Only colors meeting the weathering requirements as outlined in Section 9.7, Weathering, are covered by this specification. Anodizing process recommendations of the dye manufacturer are to be strictly followed. Additional coating thickness in excess of Class I may be necessary for exterior color-fastness. Electrodeposited coatings may also be over-dyed.
Architectural Coordination DetailsFenestration details provided in architectural drawings, at bid or contract document stages, usually in large 1” = 1’-0” or 3” = 1’-0” scale, indicating fenestration external and internal profiles, adjacent materials, and interfaces; along with scope definition and coordination notes. These are typically generated as supplemental or overlaid 2-D drawings, not solely as “views” of the overall building BIM model.
Architectural Profile DetailsFenestration details provided in architectural drawings, at concept or design- development stages, usually in small 1/16” = 1’-0” or 1/8” = 1’-0” scale, indicating fenestration external profiles only, without great detail in adjacent materials, and interfaces. These are typically generated as “views” of the overall building BIM model.
Architectural Terrace DoorA door primarily used for terrace access in high-rise applications/buildings. Architectural terrace doors consist of one or more glazed panels contained within one master frame. The operable panels will be hinged on either jamb, and can swing either to the exterior or interior (not both). The door is not used as a primary entrance door because of the nature of the sill/threshold design used to meet performance requirements. Architectural terrace doors are not tested for limited water and meet the requirements of AAMA 910.
Architectural WallsWalls having formed framing members (usually extrusions) and sizeable areas of glass, often with opaque panel areas also.
Architectural WindowsA window in its most primitive form was an unglazed hole. Unfortunatley, some bottom end windows don’t provide much more than this. An architectural window implies a better quality, more solidly built article of construction.
AreaThermal performance characteristics of fenestration products are dependent on the vision area, spandrel area, center-of-glass area, edge-of-glass area, frame area and total area.
AreawayAn uncovered space next to the fountain walls of a building, for entrance of light and air to the basement.
ArgonAn inert, nontoxic and orderless gas used in insulating glass units to reduce heat transfer.
Argon FillThe act of filling an insulated glass unit with argon gas.
Argon Gas (Argon Filled)An inert, nontoxic gas placed between glass panes in insulated glass units in order to improve the insulating value of sealed glass units.
Armored FaceplateTamper-proof faceplate or front of a lock mortised in the edge of a door to cover the lock mechanism.
Art GlassAny of the several varieties of glass using combinations of colors, special effects of opaqueness and transparency, etc., to create an aesthetic effect. When used in windows and doors, the art glass can be incorporated into the thermal pane, therefore sealed off for protection and damage due to dirt and debris. Often times, back lighting can be incorporated into the thermal pane to illuminate the beauty of the glass.
As-Build DrawingsA drawing or print marked by the Contractor to show actual conditions of a project as constructed after construction.
ASHRAEAn acronym for the American Society of Heating, Refrigeration and Air Conditioning Engineers, a group responsible for standards for heating, ventilation, air conditioning, and refrigeration. Particularly important to green building construction is ASHRAE 90.1.
ASMEAmerican Society of Mechanical Engineers
Aspect RatioThe quotient of the long side of a glazing lite over the short side of that lite.
Assembled UnitA unit, complete in its entirety, shipped with all parts and sub-assemblies in complete connection with each other and with no separate pieces. Screens, if offered, may be shipped separately.
Assembly DrawingsDrawings that show typical cross sections of the egress window system.
ASTMAn acronym for the American Society for Testing and Materials. An non-profit that develops and publishes standards, definitions of materials, methods for testing materials, recommended installation practices, and specifications for materials.
Astm (American Society For Testing And Materials)A group that develops test methods and materials standards that are widely used by the construction and building design industries. Considered one of the bases for acceptable testing levels of quality for materials used in construction.
AstragalAn astragal is commonly used to seal between a pair of doors. The word “astragal” comes from the Greek and Latin for “vertebra,” and the original astragals used in architecture were made in a beaded design, thereby resembling a vertebra.
Asymetrical Insulating Glass UnitInsulating glass units in which the panes of glass are of a different thickness or type or both.
At-Rest PositionThe position of the levers of the handle set when not in use. The at-rest position of the levers is typically horizontal.
AtriumA large enclosed open space with the shell of a building.
Atrium GlazingHorizontal (or similar) light transmitting material located in the roof sections of the atrium space; the glazed area is assumed to be uniformly distributed over the entire atrium roof with a minimum of ten percent of the gross glazed area used for structural support members.
Authentic Divided Lites (ADL)Also known as True Divided Lites (TDL). See True Divided Lites.
Auto AdhesionThe adhesion of a specific uncured sealant to the same cured sealant.
Automatic OperatorPower-operated door activating device and control, actuated by approaching traffic or remote switch.
Auxillary TestsAdditional mandatory testing of a specimen as outlined in Clause 9.3.6 of 101/I.S.2/A440-11
AwardThe acceptance of a bid or negotiated proposal by an owner.
AWGAmerican Wire Gauge
AwningWindow very similar to a side hing casement except that the sash is hinged at the top and not the side. Awnings always swings out.
Awning, Hopper And Projected WindowA window consisting of one or more sash hinged at the top or bottom which project outward or inward from the plane of the frame. An awning rotates about its top hinge(s) and projects outward. A hopper window rotates about its bottom hinge(s) and projects inward.
AzimuthThe horizontal angle subtended between two planes, one being the plane passing vertically through the position of the sun and normal to the earth’s surface and the other being the plane aligned to the north and south, and normal to earth’s surface.



Back CheckA resistance to cushion and slow down the opening swing of a door before reaching the closer swing limit.
Back ClosureComplementary member used in forming tube for side jamb.
Back DamThe rear upturned leg of a masonry sill, sill pan or sub-sill designed for the purpose of diverting liquid water. A sealant joint can also be used to form a back dam provided it is part of a continuous air seal.
Back Plate (A.K.A Escutcheon)A plate typically featuring a bearing for the rotation of a lever. It is also used to cover and protect bored preparations used to install hardware in the door.
Back StopA mechanical feature of a door closer which completely stops the opening swing of a door at a pre-set position.
Back UpA material placed into a joint, primarily to control the depth of the sealant.
BackbandBackband moldings are used in conjunction with Casing or Baseboard to create a wide variety of trim options for windows and doors. Adding an extra piece of back band moulding can add that extra boost of architectural interest.
BackbeddingThe bedding of glazing compound which is placed between the face of glass and the frame or sash containing it.
Backer RodA material placed into a joint, primarily to control the depth and shape of the sealant. Also serves as a bond breaker.
BacksetThe distance from the front of the face plate of the locking hardware to the rotation axis of the actuation lever or knob.
BaffleA shielding surface in a test apparatus located to separate the specimen from the heating or cooling equipment.
BalanceA mechanism, used in single- and double-hung windows, that offers a counterbalance to the weight of the window’s sash when opening and closing. Comes in visions of constant force balance, spiral balance and block-and-tackle balance.
BalanceA mechanical device used in hung windows as a means of counterbalancing the weight of the sash.
Balance Rated Travel Range (Brtr)The rated travel range of the balance as specified by the manufacturer.
Balanced DoorA door equipped with double-pivoted hardware so designed as to cause a semi- counterbalanced swing action when opening.
BalconyAn exterior floor that projects from the wall of a building, is completely supported by the building structure, and is enclosed by a parapet or railing.
BalusterAny of a number of closely spaced vertica decorative supports for a railing or balustrade.
Barrier FreeThe elimination of barriers or obstructions to permit ready access to and through entrances for those who are confined to wheelchairs or otherwise physically handicapped.
Barrier SystemsThe location of the weatherability is determined by the integrity of the first (exterior) surface of the wall and the first surface of the window or door. The two surfaces are usually connected together by a sealant joint, effectively creating the water barrier for the building.
Barrier SystemsThe location of the weatherability is determined by the integrity of the first (exterior) surface of the wall and the first surface of the window or door. The two surfaces are usually connected together by a sealant joint, effectively creating a water barrier for the building.
Barrier WallA wall system that is intended to manage all water at the exterior surface.
Baseline UnitOne test specimen representative of the product line under evaluation fabricated using standard construction for that product line with the highest conductivity glazing option for that product line. A baseline test specimen glazed with an insulating glass unit (IGU) shall be filled with air.
Basement WindowAny window type intended for the purpose of ventilating or illuminating a basement or cellar.
Basic Wind SpeedThe wind velocity used to calculate external pressures acting on a surface or structure. Basic Wind Speed is expressed in miles per hour (mph) or kilometers per hour (kph) and is based on wind speed maps included in building codes or other related standards.
Bay WindowsUsually a projecting combination of three windows, arranged with two operating and one fixed picture window, where the fixed window is parallel to the wall and usually half the total width of the opening.
BeadOften called a “stop” or a “bead stop”, a bead is a wood strip against which a swinging sash closes. Also, a finishing trim at the sides and top of the frame to hold the sash, as in a fixed sash or a double-hung window. A strip of sealant, glazing compound or putty.
BeamA horizontal load-supporting member of a building which directly supports a floor; may be of wood steel, or concrete; transmits load horizontally to vertical columns or bearing walls. Normally beams are larger and are spaced further apart than “joist.”
BearingThe area of contact between a structural member (beam, girder, footing) and its underlying support (column, bearing wall, load bearing ground).
Bearing WallA wall which supports any vertical load in a building (such as floors, roofs, joist, beams or girder) as well as its own weight.
Bed Or BeddingThe bead of compound applied between two materials, normally the glass or panel and the stop or frame.
Bedding Of StopThe application of sealant at the base of a channel, just before the stop is placed in position, or buttered on the inside face of the stop.
Beige ProfileA profile, the color of which is defined by the color space falling within the parameters LH = 61 to 87, aH = -2.5 to 4.0, and bH = 6.5 to 23.
Bent GlassGlass that has been curved by heating to above its softening point and then bent by gravity or press molds; also termed “curved glass.”
BETECAn acronym for the Building Enclosure Technology and Environment Council. A voluntary membership council of the National Institute of Building Sciences. BETEC is charged with encouraging optimum energy use of buildings through a better understanding of how overall, complex building components interact with each other and with the environment.
Between Glass MuntinA small profile member installed between the lites of glass, in a sealed insulating glass unit, to simulate individual glass lites.
BevelA sloped or canted surface contiguous with a vertical or horizontal one.
Bevel Of Sealant BeadIn glazing, a bead of sealant applied to provide a slanted top surface so that water will drain away from the glass or panel.
Beveled GlassIs usually made by taking thick glass and creating an angled surface cut (bevel) around the entire periphery.
BHMABuilders Hardware Manufacturers Association
BidA complete and signed proposal to do the construction work or designated portion thereof for the dollar amount stated in the bid.
BidderOne who submits a bid for a prime contract with the Owner, as distinct from a sub-bidder who submits a bid to another bidder. Technically, a bidder is not a contractor on a specific project until a contract exists between him and the Owner.
Bidding DocumentsThe advertisement or invitation to bid, instructions to Bidders, the bid form the drawings, the specifications, and any Addenda issued prior to receipt of bids.
Bi-folding DoorsBi fold doors are also known as bi-folding doors and folding sliding doors. In its simplest term, a bifold is a door that slides open while its panels fold up and stack neatly against the wall – like a concertina or an accordion.
Bi-folding WindowsWindows that fold to one side or both in a tight, compact stack.
Bim ElementsBIM elements represent different parts of a building, such as a window or door.
Bim FamiliesBIM families are collections of similar elements, such as windows, sometimes referred to as Industry Foundation Classes (IFCs).
Bim ManagerThe project executive, often employed by the construction management firm or architect of record, responsible for maintaining the project BIM model, and all related processes and protocols. The project BIM manager’s responsibilities as defined herein are not the fenestration manufacturer’s.
BIPVBuilding Integrated Photovoltaics. See photovoltaics.
BiteAmount of overlap between the stop and the panel or light. The distance that the surround member (rail or stile) overlaps the glazing.
BiteThe dimension by which the inner or outer edge of the frame or glazing stop overlaps the edge of the glazing.
Bite FailureGlazing or infill panel disengagement from the fenestration system that is attributed to an inadequate bite.
BituminousDescribing cement, mastic, or roofing, indicating a product in which asphalt is a major ingredient.
BlackbodyThe ideal, perfect emitter and absorber of thermal radiation. It emits radiant energy at each wavelength at the maximum rate possible as a consequence of its temperature, and absorbs all incident radiance.
BlankThin plastic sheeting or other suitable material applied to the exterior surface of the test specimen (tare reading).
Blast (Explosion)A rapid chemical or nuclear reaction that produces sound, heat, light and a shock wave.
Blast ConsultantAn individual, firm or institution employing such persons that have demonstrated experience with the accepted practices for blast resistant design.
Blast EventAn explosion resulting in a time-dependent variation of air pressure that radiates from the explosion.
Blast TestsTests designed to simulate the effects on an explosion.
Blast-Resistant WindowsWindows resistance to blast and blast-type attacks.
BleedingA migration of a liquid to the surface of a component or into/onto an adjacent material.
Blind NailingNailing in such a way that the nail heads are not visible on the face of the finished work.
Blind StopThe blind stop serves the same purpose as the inside stop, except it is positioned for function on the exterior of the window. Often serve as a stop for storm windows and screens.
BlisterA rounded elevation of the pultruded surface with boundaries that may be more or less sharply defined.
BlockA small piece of elastomeric or other suitable material used to support or position the glass in the frame
Block Frame Fenestration ProductA type of non-finned fenestration product (either window or door) that has no factory-applied moldings and that is installed into the rough opening either by driving fasteners through shimmed side jambs or by use of installation clips or brackets. (Sometimes called “Box Frame”.)
Block Frame WindowReplacing a window that utilizes the existing wood perimeter frame of the old window.
BlockingA lineal piece of suitable material designed to support and prevent rotation of the replacement window sill.
BOAFBuilding Officials Association of Florida
Board FootA unit of measure represented by a board one foot long, one foot wide and nominally one inch thick, or 144 cubic inches.
BOCAAn acronym for Building Officials and Code Administrators International. Development and enforcement of building codes.
BondThe arrangement of bricks in certain overlapping patterns to give the finished structural unit additional strength and to allow the individual elements to act together as a cohesive, integrated unit. Commonly used bonds are Running, common, English, and Flemish bonds.
Bond BreakerA material used to prevent three-sided adhesion in sealant joints.
BookfoldAll four or three wings of a revolving door folded so that they are parallel and point in the same direction.
Boot GlazedThe rubber gasket that cups the edge of a piece of glass perimeter installation into a sash.
Borrowed LightAn interior window between rooms which allows light from one room to enter another – It is an older term, but not entirely out of use – use instead “glazed opening.
Bottom ArmThe arm mechanism attached to the bottom rail of a door and connecting to the spindle of a floor closer or pivot.
Bottom RailThe horizontal bottom part of a window sash.
Bottom SweepA flexible weatherstripping attached to the bottom of a door to prevent the infiltration of air, water, insects or sound.
Boundary LayerThe atmospheric layer from the ground surface up to a height where ground based obstacles such as buildings, trees and low hills cease to affect wind characteristics. In this layer the vertical distribution of mean wind speed, turbulence intensity and scale (gustiness) are determined primarily by surface features.
Boundary Layer Wind Tunnel (Blwt)A low velocity wind tunnel with a long test section designed to physically model the atmospheric boundary layer. The floor of the wind tunnel is covered with surface features scaled to the same scale as the structure under study so as to develop a boundary layer with air flow characteristics similar to those for the actual site.
Bow WindowA rounded bay window that projects from the wall in an arc shape, commonly consisting of four or more sashes.
Box BayA window style of a bay window with the side windows that project away from the home’s exterior at 90 degree angles and the center picture window is parallel to the wall.
Box StrikeSee STRIKE.
BoxframeDoor or window frame with no exterior casing or flange for mounting to a wall. (a.k.a. Non-Flanged Door/Window)
Brake ShapeSheet stock bent or “broken” to desired shape, as required by specific job, on a power or manual brake machine. This shape is often used to cover conditions which cannot be covered by stock shape.
Breakaway ForceThe force required to start a sash (or panel) in motion from a fully closed position.
Breakaway MechanismSee COLLAPSING MECHANISM.
BreakoutIndividual fiberglass strands which are loose or frayed, typically near fabricated edges.
Breather TubeSimilar to “Capillary Tubes”, are metal tubes placed in the edges of insulated glass units to accommodate for pressure changes during shipping over high altitudes. The tube is sealed upon installation.
Brick MoldAn exterior trim molding forming a boundary between bricks or other siding and a window or door. It is sometimes provided with a recess to receive a screen or storm door.
Brick Moldingrefers to the exterior trim on all types of windows and doors, whether the house is brick or not.
BridgeThe portion of the extruded framing member which connects the exterior face with the interior structural portion of the frame. This portion of the thermal break cavity is removed by sawing or milling after pouring and curing of the thermal break material
British Thermal Unit (Btu)The heat required to increase the temperature of 1 lb. of water 1 degree F.
BrokerA person who buys and sells goods or assets for others.
BTUAn abbreviation for British Thermal Unit. This is the heat required to increase the temperature of one pound of water one degree Fahrenheit.
BubbleAn inclusion of a gaseous or liquid material within the vinyl or at the glass-vinyl interface.
BubblingOpen or closed pockets in a sealant caused by release, production, or expansion of glasses.
BuckA rough wooden framework built into a window or door opening in a concrete or masonry wall, to which the window or door frame is secured.
BudgetThe sum established by the Owner as available for the entire Project, including the construction budget, land costs, equipment costs, financing costs, compensation for professional services, contingency allowance, and other similar established or estimated costs.
Building EnvelopeThe outer elements of a building, both above and below ground, that divide the external from the internal environments.
Building Information Modeling (Bim)An integrated construction project workflow and process, in which up-to-date, reliable information is used to coordinate design, manufacturing, and construction activities of all parties involved, with information kept in a single building model.
Building PaperA membrane material made of cellulose paper impregnated with asphalt (to inhibit passage of liquid water through the material) and which is commonly used as a concealed water-resistive barrier (WRB), similar to polymer house wraps, in membrane/drainage walls.
Building PaperA membrane material typically made of cellulose paper impregnated with asphalt (to inhibit passage of liquid water through the material) and which is commonly used as a concealed water-resistive barrier (WRB), similar to polymer house wraps, in membrane/drainage walls.
Building PermitA permit issued by a village, town, city, county, state or federal governmental authority allowing construction of a project in accordance with approved Drawings and Specifications.
Building Seismic Safety Council (Bssc)The Building Seismic Safety Council was established in 1979 under the auspices of the National Institute of Building Sciences (NIBS) for dealing with the complex regulatory, technical, social, and economic issues involved in developing and promulgating building earthquake hazard mitigation regulatory provisions that are national in scope. Building Seismic Safety Council, 1090 Vermont Avenue, N.W., Suite 700, Washington, DC 20005.
Building TypeA classification of a building according to principal activities or uses for which it was constructed, such as housing, jail, shopping center. This is not the same as an “occupancy type” of building codes.
BulkheadThe member of an entrance frame which forms a base for a sidelight.
Bull-NoseConvex rounding of a member, such as a radius face plate.
Burglar Proof DoorsReinforced doors designed to be secure and to frustrate any attempted burglary.
ButtAbbreviation for Butt Hinge, which is a hinge designed for application to the edge of a door.
Butt GlazingThe installation of glass products where the vertical glass edges are without structural supporting mullions
Butt JointA meeting of two members squarely end to end.
ButteringApplication of sealant compound to the flat surface of some member before placing the member in position, such as the buttering of a removable stop before fastening the stop in place.
Butt-Hung DoorA door hung on Butt Hinges.
ButylA synthetic rubber, or elastomer, butyl rubber is impermeable to air and used in many applications requiring an airtight rubber. Often used around windows and doors.
By OwnerThe term “by others” means that work shown or described in the contract documents and labeled with this designation is not included in the specific sub-trade’s contract, but will be required to be done within the General Contractor’s contract.
BypassA bypass door is a type of door system often used with closets. Bypass doors open by sliding on a track behind/in front of each other.



CABOCouncil of American Building Officials
Cam LockOn a double hung or single hung window, a hardware that pulls the sash together and locks the window.
CamberA slight rising from a plane to gain an actual or apparent effect of arching.
CamingRefers to the grooved metal bars that hold textured glass and bevels in place, creating a decorative art glass design.
Cap BeadA beveled seal applied to the top of the glazing rabbet to shed water away from the glazed infill.
Capillary TubesSimilar tol “Breather Tubes”, are metal tubes placed in the edges of insulated glass units to accommodate for pressure changes during shipping over high altitudes. The tube is sealed upon installation.
CapstockThe outer layer in a co-extrusion generally exposed to weathering. It could also be the outer layer designated for color, appearance or other performance criteria.
Carbon NeutralA term used to describe the action of organizations, businesses and individuals taking action to remove as much carbon dioxide from the atmosphere as each put in to it.
CasementA window sash that swings open on side hinges: in-swinging are French in origin; out-swinging English. Hardware can be a hand crank, push bar or a lever handle.
Casement WindowA window consisting of one or more sash hinged to open from the side (adjacent to the jambs), which project outward or inward from the plane of the window in the vertical plane.
CasingExposed molding or framing around a window or door, on either the inside or outside, to cover the space between the window frame or jamb and the wall.
CatalystA material which speeds the cure of a compound.
CaulkTo fill or close seams or crevices of in order to make watertight, airtight, etc
CaulkingIs both the processes and material to seal joints or seams in various structures. Commonly made of silicone, bituminous, acrylic, or rubber-based material.
CavityThe hollow, channel or void provided in the extruded framing member into which the liquid thermal break material is poured.
Cavity To Vent RatioThe volume of the drainage and ventilation cavity in m3 (ft3) between the rain screen and the air/water barrier, divided by the area of the vent in the rain screen in m2 (ft2). It does not include the volume of rigid non-air permeable insulation such as closed cell foams, but does include the volume of fibrous insulation such as mineral wool insulation. The cavity to vent ratio shall be expressed as m3/ m2 (ft3/ft2).
Cavity WallA type of building wall construction consisting of an outer wall secured to an inner wall separated by an air space.
Cellular PVCCellular PVC is made from a foam extrusion process that creates not only a stronger but a lighter material for many applications, including replacement windows. Cellular PVC is roughly 140 percent more durable than vinyl and has roughly double the insulation properties.
cellulose Composite MaterialA composite material whose ingredients include cellulose elements. These cellulose elements appear in the form of, but are not limited to, distinct fibers, fiber bundles, particles, wafers, flakes, strands, and veneers.
Cement CasingThe pan installed in the floor to house the floor bearing and/or operator of a revolving door or the floor mounted operator or closer for a swinging door.
Cementitious MaterialMaterial binding aggregate particles together into heterogeneous mass.
Center Pivot WindowsAlso referred to as a center hinge window. The hinges of a window sash that are centrally located in the frame so that the window rotates horizontally about its center line. Often incorporated in round windows that are required to open.
Center ShaftThe vertical shaft to which the wings of a revolving door are fastened.
Center-Hung DoorA door hung on center pivots.
Center-Of-Glass Area (Cog)For thermal transmittance, this includes all vision area except the area within 64 mm (2.5 in.) of the primary sash or frame. For VT and SHGC determination, center-of- glass area is taken to be the vision area.
Center-PivotSwing hardware having its pivot axis on the thickness centerline of the door and normally located about 2 from the hinge jamb.
Centor Pivot DoorsA door that is supported by, and swings about, pivot pins. The pins are inserted into or attached to the door on the center line of its thickness.
CertificationA process that indicates a representative sample of a product line has been tested, that the product meets specified requirements, and that the product is subject to ongoing inspections by an outside certification agency.
Certification for PaymentA signed statement from the Architect to the Owner confirming the amount of money due the Contractor for Work accomplished and/or materials and equipment suitably stored.
Certification ProgramA program sponsored by a HUD approved organization concerned with product evaluation. This organization maintains periodic testing, inspection and listing of products that meet this standard.
Certified ProductA product which meets all requirements of the certification program and is included in that listing.
Certified WoodWood and paper products come from responsibly managed forests – as defined by a particular standard.
CFMCubic Feet per Minute.
CFRCode of Federal Regulations
Change OrderA written order to the Contractor signed by the Contractor, Owner, and the Architect, issued after the execution of the Contract, authorizing a Change in the Work or an adjustment in the Contract Sum or the Contract Time. The Contract Sum and the Contract Time may be changed only by Change Order.
ChannelA three-sided, U-shaped opening in sash or frame to receive light or panel, as with sash or frame units in which the light or panel is retained by a removable stop. Contrasted to a rabbet, which is a two-sided L-shaped opening, as with face-glazed window sash.
Channel DepthThe measurement from the bottom of the channel to the top of the stop, or measurement from sight line to base of channel.
Channel GlazingThe sealing of the joints around lights or panels set in a U-shaped channel employing removable stops.
Channel WidthThe measurement between stationary and removable stops in a U-shaped channel at its widest point.
ChaseA rough channel formed in the inner face of a wall to receive piping, wiring, or duct­work and keep it behind the finished surface.
Check RailAlso referred to as a meeting rail, it is the horizontal bottom rails on the upper and horizontal top rail on the lower sashes that meet when a double-hung window is closed.
Check StileSee Meeting Stile
Chemical Compatibility“Chemical Compatibility” is in accordance with a definition outlined in ASTM C717, “Standard Terminology of Building Seals and Sealants.” Compatibility is defined as the capability of two or more materials that can be placed in contact or close proximity with one another with each material maintaining its usual physical or chemical properties, or both. Specifically, this is to ensure that the components do not interact (chemically or otherwise) to the extent that their properties are altered, which could adversely affect the performance of each component.
Chemical Curing SealantA sealant that cures primarily through chemical reaction.
Chemically Bonded(When related to a welded corner) A process where the two polymer profiles or pieces are heated and fused together with the aid of a chemical reaction. The reaction and bonding is similar to the original extrusion process.
Chemically Strengthened GlassGlass that has been strengthened by an interchange of molecules at the glass surface, the modified molecules are larger than the original, placing the glass surface in compression.
ChipsMinor damage to the pultruded or coated surface that removes material, but does not cause a crack or craze.
ChordFor bent glass, the dimension measured straight across the bend.
Chromogenic GlazingA broad class of switchable glazings including active materials (i.e.: electrochromic) and passive materials (photochromic and thermochromic).
Circle TopSometimes called a round top, arch top or circle head, are semi-circular windows that usually accompany common rectangular-shaped windows. They allow more external light to enter, but normally don’t open. So, added ventilation isn’t a consideration. Circle-top windows creatively enhance their companion windows, providing a sense of richness and sophistication.
CladdingSometimes referred to as window wrapping, Refers to the application of aluminum or vinyl sheeting cut and formed to create a covering or coating attached to the exterior face of a door or window to provide a low-maintenance surface.
Cladding SupportA sub-support between the exterior wall cladding and the building frame that acts to transfer loads back to the structure. Not to be confused with panel stiffener, which typically acts to limit cladding deflection.
Cladding SystemMaterial assembly applied to a building as a nonload-bearing wall, or attached to a wall surface as a protective and ornamental covering.
Clash DetectionIdentification of physical interference between building components in a virtual (modeled) environment.
Class I (A4)High performance anodic finishes used in exterior applications receiving periodic maintenance such as curtain walls. Minimum coating thickness of 18 microns (0.7 mil).
Class Ii (A3)Commercial anodic coatings used in interior applications or exterior applications receiving regularly scheduled cleaning and maintenance such as storefronts. Minimum coating thickness of 10 microns (0.4 mil).
Clear Anodic Coatingselectrolytes. These coatings are transparent and allow the natural aluminum color to show through.
Clear GlassArchitectural clear glass is mostly of the soda-lime-silica type, and composition varies between manufacturers, but is generally 70 – 74 percent silica, 5 – 12 percent lime, and 12 – 16 percent soda, with small amounts of magnesium, aluminum, iron, and other elements.
ClerestoryA window in the upper part of a lofty room that admits light to the center of the room. Historically, clerestory denoted an upper level of a Roman basilica or of the nave of a Romanesque or Gothic church, the walls of which rise above the rooflines of the lower aisles and are pierced with windows.
Climate ChangeA change in global or regional climate patterns.
ClipsWire spring devices to hold glass in a rebated sash, without stops, and face glazed.
COCarbon Monoxide
CoalescenceTo unite, to join together.
Coated GlassGlass with a very thin film use as a reflective surface.
CoatingA protective and/or decorative layer applied to a surface without the use of an adhesive.
Coating/Finishesgreater thickness, density and hardness of these factory-produced finishes. They may be clear (natural) or colored. Color is electrolytically deposited or integral. Pre- anodic chemical treatments clean and prepare the aluminum for the anodic finish.
CodesRegulations, ordinances or statutory requirements of a village, town, city, county, state, or federal government relating to building construction, adopted and administered for the protection of the public health, safety, and welfare.
Coefficient Of ExpansionA value denoting the rate at which a material expands with rising temperature.
Coefficient Of VariationA fraction or percentage indicative of the variability or distribution of a value.
CoextrusionProfiles extruded from two or more concentric streams of compounds. The separate streams may be compounded to provide different characteristics such as strength or weathering.
Cohesive FailureFailure characterized by splitting within the sealant resulting from over-extension.
Cohibition PointRetraint point. A location where movement is restricted between the sash and the frame.
Coil StockStock rolls of aluminum used for custom exterior trim.
Coil-Applied CoatingThe process of applying a resinous coating onto a coil of aluminum, and curing it into a continuous film, prior to the fabrication process.
Coincidence DipA frequency or set of frequencies at which the sound transmission loss across a material will decrease due to the resonant characteristics of the material.
Cold FlowDeformation, under gravitational force, at or below room temperature.
Collaboration SoftwareAn application that facilitates file sharing, reading various file types and bringing them together in one user interface.
Collapsing MechanismThe revolving door mechanism, top and bottom, that allows the door to turn properly and breakaway when required.
Colored MarkingDiscoloration on the surface of the pultruded product that cannot be removed by rigorous cleaning.
Color-Hold GuidelinesPredictive target color regions within a three-dimensional model which constitute acceptable appearance retention levels of color change resulting from weathering of a specific product type and color.
ColumnA supporting pillar.
Combination AssemblyAn assembly formed by a combination of two or more separate fenestration products whose frames are mulled together utilizing a combination mullion or reinforcing mullion.
Combination DoorsA door composed of a prime door with a storm door affixed to the exterior face of the assembly. Combination doors are offered by the manufacturer as a complete factory pre-assembled or integral unit. Operation of the prime door and storm door shall be completely independent of each other. Combination doors are marked and tested as single integral units.
Combination MullionA horizontal or vertical member formed by joining two or more individual fenestration units together without a mullion stiffener.
Combination Storm WindowA window that is made of a storm window with screen and primary window combined.
CombustionA chemical process of oxidation that occurs at a rate fast enough to produce a temperature rise and usually a light, either as a glow or flame.
Commercial Building (As Defined In The Iecc)All buildings other than detached one- and two-family dwellings, townhouses and residential buildings, Groups R-2 and R-4.
Commercial Entrance SystemA system of products used for ingress, egress and rescue in non-residential buildings. Commercial entrance systems typically utilize panic hardware, automatic closers, and relatively large amounts of glass. Commercial entrance systems are often site assembled. They are typically subject to high use and possibly abuse and are designed to withstand such use and abuse.
Commercial GlazingGeneraly referring to commercial or architectural applications of glass for windows and doors.
Common MullionsOccur when two or more similar units are assembled in rows or ribbons (back to back). The individual units must be tested to the appropriate section(s) of this standard, but may be either factory or field mulled. Evidence of compliance shall be either by testing or mathematical calculation.
Compartmentalization (Segmentation)The principle of dividing the vent and drainage cavity into smaller confined air cavities to control vertical or horizontal air flow inside the wall for the purpose of maintaining the pressure equalized air space.
CompatibilityWhen materials maintain physical and functional properties when in direct contact or close proximity to each other. The ability of two or more materials to exist in close association for an indefinite period with no adverse effect of one on the other.
CompatibleTwo or more substances which can be mixed or blended or in close proximity without separating, reacting, or affecting the material adversely.
Compatible MaterialsMaterials that can exist in contact or close proximity to one another without detrimental effects on either.
CompleteThe term “complete” means all surfaces or areas of a construction  item.
Complete Window ReplacementThe installation of a replacement window where the previously installed window (frame and sash) is completely removed.
CompliantExpression of dissatisfaction (other than Appeal) to the AAMA Validator or Chief Engineer, Certification Programs by a licensee, any person, or organization, relating to either the operation of the certification program or qualifications of a certified product, where a response is expected. Complaints and responses must be in writing. If the complainant deems the response unsatisfactory, he may file an Appeal.
Composite Framecomposite windows or doors are made from a mixture of synthetic and natural materials, such as vinyl and wood, which is held together by an epoxy resin. May also mean two or more separate materials for example, an interior wood element with an exterior fiberglass element.
Composite MaterialsWindow and door members that are comprised of two or more materials. They are structurally combined or connected so as to perform structurally as a singular material, e.g., poured and de-bridged aluminum shapes, fiberglass, and man-­made wood products.
Composite MaterialsWindow and door members that are comprised of two or more materials. They are structurally combined or connected so as to perform structurally as a singular material (e.g., poured and debridged aluminum shapes, fiberglass, and man-made wood products).
Composite SectionA framing member consisting of an interior and exterior extruded aluminum section, both of which are mechanically joined by a polyamide structural thermal barrier to improve the thermal performance of the assembly.
Composite UnitA fenestration product consisting of two or more sash, leaves, lites or sliding door panels within a single frame utilizing an integral mullion (not to be confused with products made from cellulose composite materials).
Composite WindowsRefers to a window made of several compounds. Examples are fiberglass windows, Andersons fibrex and pultrusion window products.
CompoundA formulation of ingredients, usually grouped as vehicle or polymer pigment and fillers, to produce caulking compound, elastomeric joint sealant, etc.
CompressionPressure exerted on a sealant in a joint, as by placing a light or panel in place against bedding, or placing a stop in position against a bead of sealant.
Compression GasketA gasket designed to function under compression.
Compression SetThe permanent deformation of a material after removal of the compressive stress.
Compression StrengthThe maximum compressive stress which a material is capable of sustaining. Compressive strength is calculated from the maximum load during a compression test and the original cross-sectional area of the specimen.
Concentrated LoadA force applied to a fixed point load on a window, door, TDD, SSP, roof window or unit skylight component.
Concrete Masonry Unit (Cmu)A pre-cast masonry block used to construct walls.
CondensationThe deposit of water vapor from the air on any cold surface whose temperature is below the dew point, such as a cold window glass or frame that is exposed to humid indoor air.
Condensation GutterA trough for carrying off condensed water; this may be drained to the exterior or allowed to evaporate.
Condensation Resistancereferred to as “CR” measures how well a window resists the formation of condensation on the inside surface. CR is expressed as a number between 1 and 100. The rating value is based on interior surface temperatures at 30%, 50%, and 70% indoor relative humidity for a given outside air temperature of 0° Fahrenheit under 15 mph wind conditions. The higher the number, the better a product is able to resist condensation. CR is meant to compare products and their potential for condensation formation. CR is an optional rating on the NFRC label.
Condensation Resistance Factor (Crf)A rating number obtained under standard test conditions as prescribed in AAMA 1503. The CRF is essentially the ratio of the difference between an average inside surface temperature and the outside air temperature, and the difference between the inside air temperature and the outside air temperature. The CRF allows for comparison of the relative performance of fenestration systems based on the point at which an objectionable amount of condensation occurs. The CRF is dimensionless and expressed as a number between 1 and 100. The higher the CRF, the higher the resistance to condensation.
ConditionedSpace within a building that is provided with a heating and/or cooling system.
Conditioned SpaceAn area or room within a building that: (a) is heated or cooled by any equipment or appliance; (b) contains un-insulated ducts; or (c) has a fixed opening directly into an adjacent area or room that is heated or cooled by any equipment or appliance or contains un-insulated ducts.
ConductionOne of the three ways in which heat is transferred through a medium from an area of higher temperature to an area of lower temperature.
ConductionThe transfer of heat through matter, whether solid, liquid, or gas.
ConservatoryA sunroom featuring a high percentage of glazed surfaces used as walls and roof systems.
ConsistencyDegree of softness or firmness of a compound as supplied in the container, and varying according to method of application, such as gun, knife, tool, etc.
Construction DocumentsThe term “Construction Documents” means the Scope of Work. List architectural drawings, specifications, shop drawings, manufacturing details, test reports or contracts, building permits, applicable codes.
Construction JointThe linear void between two adjacent building elements.
Construction ManagementThe combined operations for the authorization, purchasing, supervision, accomplishment, and acceptance of a construction project.
ConsultantAn individual or organization engaged by the Owner or Architect to render professional consulting services, supplementing the Architect’s services. Types of consultants could be Engineers, acoustical, energy, or cost consultants.
Contract AdministrationThe duties and responsibilities of the Architect during the Construction Phase, which includes observation of construction, checking shop drawings, and approving pay requests.
Control JointA joint acting to regulate the location and degree of cracking and separation resulting from the dimensional change of different elements of a structure.
ConvectionOne of the three ways in which heat is transferred. The tendency of heat transfer process involving motion or currents of hotter, less dense air to rise, and cooler, denser air to sink, causing the transfer of heat.
CoordinatorA mechanism which controls the order of closing of a pair of swing doors, used with doors equipped with overlapping astragals and certain panic hardware which requires one door to close ahead of the other.
COPCoefficient of Performance
CopeTo join two molded strips at an angle by fitting one over the other, instead of mitering.
Co-PolymerA polymer containing two or more chemically different types of monomers.
Corner BracketA bracket which is connected to a door frame jamb and head at the upper hinge corner to support an exposed overhead door closer. Used only on out-swinging doors.
Corner PostA glass-holding mullion which connects two plates of glass at an angle, forming a corner.
Corner SealFormed when a sealant is installed to prevent air and water intrusion at corner details.
CorniceAny horizontal decorative molding that crowns a building or furniture element— the cornice over a door or window, for instance.
CorrosionThe deterioration of metal by chemical or electro-chemical reaction resulting from exposure to weathering, moisture, chemicals or other agents or media.
Cottage Windowa double-hung window with an upper sash at 1/3 size and bottom sash 2/3 size. This is inverse to an Oriel style window where the top sash is larger at 2/3 size and bottom sash is smaller at 1/3 size.
Counter-FlashingHorizontally applied sheet (flashing) material that joins layers of flashings where they join the weather resistant barrier, enhancing drainage by gravity.
CouplingThe ability of materials that are rigidly connected, to transmit vibrations or sound energy from one point to another location. The amount of energy transfer will depend upon the type of material.
Cover PlateA finish plate used to cover the exposed face of a floor closer not covered by the threshold; also, a plate used to cover the exposed face of a closer mounted in the head of a door frame or a section of threshold over a floor closer.
CoveringA surface or component that provides protection or security by its position over a space. Coverings include, but are not necessarily limited to roofs, roof systems, glazed surfaces, screened panels or other similar assemblies.
CPSCConsumer Products Safety Commission
Crash BarThe cross bar of a panic exit device, serving as a push bar to actuate the panic hardware.
Crash Bar HousingThe housing at either end of a crash bar which is mounted on the surface of a door.
CreepTime dependent part of strain resulting from stress.
CremoneA locking device consisting of two long rods, the ends of which engage at sill and head.
CRFThe AAMA rating is called the Condensation Resistance Factor (CRF). CRF numbers for windows range from 30 to 80; the higher the number, the better the window is at resisting condensation.
Cripple StudA short stud above or below a window or door opening.
Critical InterfaceThe interface between the fenestration product or other building component, and the surface of the building that requires protection from water intrusion. The critical interface can include, but is not limited to, any or all of the following: the mounting flange/nailing fin, exterior frame of a non-flanged product, the exterior edge of a casing of a brick mold of the fenestration product and the sheathing WRB or rough opening frame; the trim and siding/cladding interface; or it can be the nail or other penetrations through the window trim.
Cross RafterIn a skylight system, a structural framing member between rafters; generally at or near horizontal.
CSACanadian Standards Association
CSIConstruction Specifications Institute
CurbA wall or frame used to raise roof windows, skylights, or sloped glazing above the surface of the roof.
Cure TimeThe period of time that a reacting thermosetting material is exposed to specific conditions to reach a specified property level. The time required for a poured and debridged section to develop maximum physical properties.
CuringChemical process of developing ultimate properties of a finish or other material over a specified period of time. Compare to Drying.
Curing AgentOne part of a two-part sealant, which when added to the base will cause the base to change its physical state by chemical reaction between the two parts.
Curtain WallA system of an outer covering of a building in which the outer walls are non-structural, but merely keep the weather out and the occupants in. The wall transfers horizontal wind loads that are incident upon it to the main building structure through connections at floors or columns of the building. The outdoor surface may be metal, glass, concrete, or other material. Transparent assemblies are referred to as vision panels, and opaque assemblies are referred to as spandrel panels.
Curved GlassSee BENT GLASS.
Custom Made WindowsWindow, and doors, that are made to custom size, shape, operations, wood species, finishes, hardware, glass and obscurity
Custom SizedWindows made to a size other than manufactures standard selection of sizes.
Cut-Back(For replacement windows without old frame tear-out.) The difference between the measured opening size and the manufactured frame dimensions that allows the installation of the window with the manufacturer’s recommended clearances. Similar to Rough Opening Gap for new windows.
CWDMACanadian Window and Door Manufacturers Association
Cyclic BendingThe repeated application and removal of a bending load to a framing member so as to investigate fatigue life, composite interaction, possible changes in physical properties, etc.
CylinderThe cylindrical mechanism which receives the key used to operate a locking mechanism.
Cylinder CamUsually refers to the flat metal plate on the end of a mortise type cylinder, serving to actuate the lock mechanism.
Cylinder GuardHardened protective shield to prevent pulling of cylinder.
Cylinder RingSpacing collar to accommodate longer cylinders.



Dade County Approved DoorsThe Miami-Dade Building Code requires that every exterior opening – residential or commercial – be provided The Miami-Dade Building Code requires that every exterior opening – residential or commercial – be provided with protection against wind-borne debris caused by hurricanes.
Dade County Approved WindowsEssentially all of Florida.
Damp SurfaceFor the purposes of this document, a ‘damp surface” is ‘damp-to-touch’ and is characterized by a lack of visible water on the surface and no transfer to the skin upon touching.
DAP Shipment“Delivered At Place” means the seller is responsible for arranging carriage and for delivering the goods ready for unloading by purchaser. The purchaser is responsible for import clearance and any applicable local taxes or import duties.
Dark Brown ProfileA profile, the color of which is defined by the color space falling within the parameters LH = 13 to 33, aH = -1.0 to 6.0, and bH = 1.0 to 6.5.
Dark Green ProfileColor defined by the color space falling within the parameters LH = 20 to 40; aH = -20 to -2; bH = -2 to 4
DASMADoor and Access Systems Manufacturers Association
DAT Shipment“Delivered At Terminal” means the seller is responsible for arranging carriage and for delivering the goods and for unloading. The buyer is responsible for import clearance and any applicable local taxes or import duties.
Daylight OpeningThe area of glass visible in a glazed sash. Or can be thought of as the area in which the sun can shine through.
DaylightingThe effective use of natural lighting from both the sun and the sky for meeting at least part of the lighting needs within an occupied space. Associated with this is an assumption that all or part of the installed lighting system uses some type of lighting control strategy to respond to the available daylight.
DDP Shipment“Delivered Duty Paid” means that the seller fulfils full responsibility for deliver. The seller has to bear the risks and costs, including duties, taxes and other charges of delivering the goods thereto, cleared for importation.
Dead LoadThe part of the total building load contributed by the structural building elements and materials.
DeadlatchA latch bolt having an auxiliary feature which prevents its retraction by end pressure when in projected position.
DeadlockA lock in which a bolt is moved by means of a key or thumb turn, and is positively stopped in its projected position.
DealerA person or firm who buys and sells goods
debridingThe process whereby the aluminum bridge connecting the exterior and interior portions of the extruded thermal break cavity is removed either by milling or sawing.
debriding TimeThe minimum time required for the mixed thermal break material to develop sufficient hardness to allow debriding.
DeckAn exterior floor supported on at least one side by an adjacent structure, posts, piers or other independent supports.
Decorative LaminateA layer of natural or synthetic material bonded with an adhesive system to the interior or exterior surface of a plastic skylight, window and door profiles.
Decorative ProfileProfiles that do not comprise part of the main-frame or sash, are not integral to the structure of the assembled unit, and/or are not components related to the retention of glass, such as decorative muntin and glazing stop profiles.
DecouplingThe ability of materials to isolate vibrations or sound energy from one point to another location. Resilient materials, such as foam or rubber would provide this type of isolation.
DeflectionThe displacement in a structural member that occurs when a load is applied to the structure.
Deflection ResistanceThe ability of the thermal break material to resist distortion due to wind loading, gasket pressure, fabrication or handling which would exceed the deflection limits specified for the product.
Degree dayA unit that represents a one-degree Fahrenheit deviation from some fixed reference point (usually 65° F) in the mean, daily outdoor temperature. See also heating degree day.
DelaminationThe separation of two or more layers or plies of reinforcing material within pultrusion.
DeleteTo take something out of the building or contract – do not confuse with “omit” which means not to install something in the first place.
DensityThe mass per unit volume of a material, i.e., the mass of the thermal break material divided by the volume of that material.
Density ToleranceInsures that the finished profiles conform to the original design, weight, and to a lesser extent, the dimensions presented in the drawings.
DesiccantIs a hygroscopic and extremely porous crystalline substance that induces or sustains a state of dryness. Is used in the sealed airspace of a window to absorb and remove moisture.
Design DisplacementThe portion of total vertical movement resulting from live load, system dead load and/or column creep and, unless otherwise specified, is defined to be 80% of the total vertical displacement (unless otherwise quantified through detailed calculations, and clearly called out in project specifications. OR The design earthquake lateral displacements, excluding additional displacement due to actual and accidental torsion. Numerically, this is the calculated elastic deflection multiplied by an appropriate deflection amplification factor that approximates the actual inelastic displacement. An earthquake that would produce ground motions at the site under consideration having a 90% probability of not being exceeded in 50 years. (Previously, some referred to this as the “probable earthquake.”) As defined in 1997 SBC
Design Earthquakeearthquake at the site under consideration that produces ground motions having 90% 501.4-00, 501.6-01 probability of not being exceeded in 50 years.” As defined in 1997 UBC: “the design . ’ basis ground motion is that ground motion that has a 10% chance of being exceeded in 50 years as determined by a site specific hazard analysis or may be determined from a hazard map.”
Design FactorFor glass, the average resistance to external loads fore given size, type and thickness GDSG 1 87 divided by the loads corresponding to the maximum allowable breaking probability.
Design Intent (Di) ModelsFenestration BIM models of standard “catalog” products, of standard size and configuration, often made available through manufacturers’ websites or industry warehousing/library sites, intended for use in early stages of design for visualization, rendering, product selection, and other high-level conceptual purposes as “basis of design.” DI models are provided prior to fenestration purchase order issuance.
Design PressureThe structural wind loading requirements
Design Wind LoadThe wind load pressure a product is required by the specifier to withstand in its end use application.
DetailA drawing, at a larger scale, of a part of another drawing, indicating in detail the design, location, composition and correlation of the elements and materials shown.
Dew PointThe temperature at which water vapor in air will condense at a given state of humidity and pressure.
Dew Point TemperatureThe temperature at which water vapor in air will condense at a given state of humidity and pressure.
DHIDoor and Hardware Institute
Die-Parting LineA lengthwise flash or depression on the surface of a pultruded part.
DiffuserA translucent glazing layer or fenestration product accessory designed to transmit direct-beam radiation diffusely, i.e. many directions.
Dimensional StabilityThe degree that an extruded profile retains its original length and resists shrinkage, after being subjected to elevated temperatures. Dimensional stability is an excellent indicator of any internal or residual stresses in the profile that may have resulted from the extrusion process.
Direct GlazeA sashless window unit in which the glass is glazed directly into a frame.
DirectedTerms such as “directed,” “requested,” “authorized,” “selected,” “approved,” “required,” and “permitted” mean “directed by the Architect,” “requested by the Architect,” and similar phrases.
DisengagementSeparation of one decking system component from another, as in a fastener head pulling completely through a plank. Disengagement does not include movement of one component relative to another.
DisplacementA vector or the magnitude of a vector from the initial position to a subsequent position assumed by a body.
DisputeDisagreement between two parties (typically a licensee and a test lab, or a licensee and a customer) which is brought to AAMA for a decision based on procedural documents. Disputes shall be addressed, in writing, to the Validator, the AAMA Chief Engineer, Certification Programs, or the Certification Policy Committee, as appropriate. A response unsatisfactory to any party may result in an Appeal.
DistortionThe optical effect due to the variation of sheet glass thickness.
Divided LightA window with a number of smaller panes of glass separated and held in place by muntins.
DividerA solid element other than a frame or sash that is used to create divided lights, including muntins as well as grilles that lie between the indoor and outdoor glass layers.
DivisionOne of the sixteen organizational subdivisions used in the specifications and in construction information filing.
Division BarA resilient member used vertically or horizontally, supporting lightweight building materials when combined with a structural element.
DockA deck designed and located for the reception of water-going vessels and the loading/unloading of people and materials to/from docked vessels.
DOE(United States) Department of Energy
DOE-2.1EA building-simulation computer program, by Dept of Energy, used to calculate total annual energy use.
Dogging DeviceA device used to lock the crash bar on a panic exit device in the open position.
DoorA means of access for the purpose of ingress and egress. A movable structure used to close off an entrance, typically consisting of a panel that swings, slides or rotates.
Door BacksetDimension from plane of face of door to plane of face of frame.
Door ClearanceThe margin of clearance around the edge of a door, between door and frame.
Door CloserA device or mechanism to control a door during its opening and closing cycle; may be overhead or floor mounted, and either exposed or concealed.
Door FrameThe assembly of members into which a door fits when closed, consisting of jambs and head but no sill.
Door HolderA hardware device designed to limit the swing of a door and hold it in an open position.
Door Light (Lite)The glass area in a glazed door.
Door OpeningThe opening dimension of a doorway, measured from inside of jambs and from floor line to underside of head of frame. The opening size is usually the nominal door size, and is equal to the actual door size plus clearances and threshold height.
Door RollersThe wheels on sliding doors that movement.
Door SystemOne or more leaves or panels contained within one master frame with a sill/threshold and with or without mullions or hardware. The operable panels are hinged or sliding. The hinged panels can swing inward or outward.
DoorbuckA door frame of rough material to which the finished door frame is attached.
DoppeltürGerman: Double door
DormerA structural element of a building that protrudes from the plane of a sloping roof surface.
Double Acting DoorA door equipped with hardware which permits it to swing in both directions from the plane of its frame.
Double GlazingIn general, two pieces of glass separated by an air space to improve insulation against heat transfer and/or sound transmission. In factory-made double glazing units, the air between the glass sheets is thoroughly dried and the space is sealed airtight, eliminating possible condensation and providing superior insulating properties.
Double SliderA sliding window with both sash slide side to side.
Double-HungA sliding window with both sash slide up and down. A counterbalance mechanism usually holds the sash in place.
Double-Hung TiltA double-hung window with the sashes made to tilt to the interior of the home for ease of cleaning.
Double-Strength GlassGlass that is 1/8″ in thickness. More exactly, sheet glass between 0.115″ and 0.133″ (2.92–3.39 mm) thick.
Drainage And Ventilation CavityA cavity which is located behind the rain screen cladding element of the wall system and is on the exterior side of the air and water barrier (AWB) that allows the system to drain and vent.
DraindownThe observed dripping/sag/flow of any component from the constructed sample as a result of the softening or liquefaction of the self-adhered flashing adhesive or sealant.
Drained Cavity Wall Claddingwall system that consists of an exterior cladding, a cavity, and an AWB to manage air leakage and water penetration. The exterior cladding sheds the majority of water. Water that penetrates the cladding is drained to the exterior of the building with flashing, drainage paths and weeps.
Dreh Kipp FensterGerman: Exact translation is “turn tilt window” or “rotary tilt window”; general meaning: tilt/turn window
DrehfensterGerman: Pivot window
DriftGenerally refers to horizontal displacement. Story drift (or inter-story drift) refers to lateral movement (displacement) of one level (story) of a structure with respect to the level (story) above or below due to the design lateral forces. Story drift is the calculated elastic drift that has been amplified by factors required by government regulations or codes.
DripAny exterior projecting fin, groove, molding or cornice at the outer edge of a sill, soffit, or other projecting member in a wall designed to interrupt and divert the flow of water away/ downward over the wall or inward across the soffit. A small groove on the underside of a drip cap or window sill to prevent water from running back under the cap or window.
Drip CapA specialty component or molding made of either wood, aluminum or vinyl installed above a window or door. Commonly installed over windows and doors to direct water away from the building in order to prevent seepage, also called a drip molding. A rounded or beveled metal strip attached to the bottom of an exterior door to prevent water from draining or blowing under the door.
Drip MoldA molding shaped for drip.
Dropped Dart Impact ResistanceMeasures the resistance of the profile to cracking or breaking during the fabrication processes, such as sawing, routing and punching. Impact resistance also indicates resistance to general abuse during transportation, storage and installation.
DrumThe curved sides of the enclosure, either glass or sheet metal of a revolving door.
Dry GlazingA flexible vinyl seal or other acceptable material that does not have adhesive properties.
Dry SealAccomplishment of a weather seal between the glass and sash by use of elastomeric or other flexible material strips or gaskets.
DryingProcess of developing, solely by evaporation of volatile ingredients, ultimate properties of a finish or other material over a specified period of time. Compare to Curing.
DTDuty assessed using the US Customs Haronized Tariff Schedule. Determined by the description and value of imports in US dollars.
Dual Action Hinged Glass DoorDual action hinged glass doors consist of one or more glazed panels contained within an overall frame designed so that one of the glazed panels is operable in a swing mode and can be tilted inward from the top for ventilation.
Dual DoorA side-hinged door composed of one of the configurations listed in Clause 4.5.1 of 101/I.S.2/A440-11.
Dual GlazingTwo layers of glazing material mounted in a common frame and/or sash, separated by a space, and sealed or non-sealed.
Dual ModeThe primary and secondary window/door, or both primary windows/doors, are closed, the primary windows/doors are locked, and the insect screen (when offered or specified by the manufacturer) is in the stored position.
Dual WindowA window composed of one of the configurations listed in Clause 4.5.1 of 101/I.S.2/A440-11 and offered by the manufacturer as a complete factory pre­assembled or integral unit.
Dual-ActionA window consisting of a sash that tilts from the top and swings inward from the side for cleaning of the outside surface. Also referred to as “tilt-turn” window.
Dual-Action Side- Hinged DoorA door system consisting of one or more leaves contained within an overall frame and designed such that one of the leaves is operable in a swing mode and can be tilted inward from the top for ventilation.
Dual-Sealed UnitsSealed insulating glass units fabricated with an inner seal and an outer secondary seal. Generally, each of the two seals has been selected for its special performance characteristic, i.e. adhesion and moisture vapor transmission properties.
DurabilityThe capability of maintaining the serviceability of a product, component, assembly or construction over a time.
DurometerAn instrument used to measure hardness of a material. Shore Hardness is a commonly used hardness measurement scale.
Dutch DoorA two piece entry door in such that the top half operates separately than the lower half.
Dwell TimeThe time from the point the test apparatus clutch slips until the apparatus changes direction.
Dynamic GlazingAny Glazing System/Glazing In-fill that has the fully reversible ability to change its performance properties, including U-factor, SHGC, or VT. This includes, but is not limited to, shading systems between the glazing layers and chromogenic glazing.
Dynamic WindowsWindows or door systems include switchable windows and shading systems such as motorized shades, switchable electrochromic or gasochromic window coatings, and systems that have variable optical and thermal properties that can be changed in response to occupant preferences.



EcologicalRelating to or concerned with the relation of living organisms to one another and to their physical surroundings
Ecologically BalancedEcological balance is a theory stipulating that natural conditions, including numbers of various animal and plant species, remain stable on their own through variations over time.
Edge BlocksContinuous or short lengths of elastomeric materials located at both jambs of the frame for centering the glass in the framed opening and for preventing lateral “walking.” They also protect the glass edges from being nicked during installation.
Edge ClearanceThe dimension between the edge of glass or panel and its surrounding frame, measured normal to the edge in the plane of the glass or panel.
Edge CoverThe dimension by which the inner edge of the frame or stop overlaps the edge of the glass or panel.
Edge EffectsTwo-dimensional heat transfer through a spacers on a glass perimeter.
Edge Slip (Edge Mismatch)An edge condition in which one component glass of a (edge mismatch) laminate extends beyond the other.
Edge-Glued JointA joint between two pieces of wood longitudinally glued edge to edge.
Edge-Of-Glass Area (Eog)For thermal transmittance, this area includes all vision area within 64 mm (2.5 in) of the primary sash or frame.
EEREnergy Efficiency Ratio
Effective Moment Of InertiaThe moment of inertia or ability of the composite structure to resist deflection under load. This property is usually determined by testing the composite rather than attempting to mathematically predict composite performance.
Effective Thermal ConductivityThe combined effects of conduction, convection, and radiation in fluid-filled (gas- filled) enclosures and cavities, converted into an apparent or effective conductivity of a solid.
Efficient WindowsThe term used to describe the double glazing or triple glazing use in modern windows in homes. Unlike the original single glazing or old double glazing, energy-efficent glazing incorporates coated (low-emissivity) glass to prevent heat escaping through the windows.
EGIAElectric and Gas Industries Association
EgressA means of exiting. An egress window is one that is large enough for an adult to exit the room in case of an emergency. The size will be defined by national or local building codes.
EgressThe act of leaving an enclosed space. In the window industry the term refers to the dimensions of the opening of a window or door (the horizontal clear distance, vertical clear distance and the area of the opening which are established by the building codes). The reason for establishing minimum egress dimensions is to insure that a person attempting to leave a building in an emergency situation will have room to maneuver. Also proper “egress” will allow a fireman to enter a home while wearing emergency equipment. In 1985, the minimum egress dimensions required by most codes are 22″ horizontally, 24″ vertically and 5.7 square feet in area. Some areas of the country use different dimensions.
Egress WindowA window that provide emergency exits in case of fire. Egress windows shall have a clear opening, measured when the operable part of the window is completely open, of 5.7 square feet and meeting the following minimum dimensions.
Egress Window SystemA “primary window” and, if provided, any screen, secondary window or other device, together with the necessary operating instructions constitute an “Egress Window System,” which complies with the requirements of this standard and that, when properly installed in a manufactured home, provides a means of egress when access to the exterior passage doors are unavailable.
EicheGerman: Oak
EIFSExterior Insulation and Finish System. A nonload-bearing outdoor wall finish system consisting of a thermal insulation board, an attachment system, a reinforced base coat, exterior joint sealant, and a compatible finish.
Elastic RecoveryElastic recovery is the ability of the cross-linked sealant to recover from a constant external deformation. Elastic recovery is a measure of the cross-linking density of the system.
ElastomerAn elastic, rubber-like substance, such as natural or synthetic rubber.
ElastomericAn elastic rubber like substance.
Elastomeric MaterialA term often used for rubber and polymers that have properties similar to those of rubber. Thermal break polymers having the elastic properties of natural rubber.
Electric OperatorUused to operate an window or door automatically.
Electric StrikeSee STRIKE.
Electrochromic Glass or glazing whose light transmission properties are altered when voltage is applied.
Electrochromic GlazingGlazing with optical properties that can be varied continuously from clear to dark with a low-voltage signal. Ions are reversibly injected or removed from an electrochromic material.
Electrodeposited Color Anodic Finishes (A44)Colored anodic coatings achieved in a multi-step process involving a clear anodizing step, followed by an electrolytic deposition of stable metal compounds at the pore base of the anodic coatings to obtain the color. A wide range of colors including the champagnes, bronzes, black, blue, burgundy, green, gray and gold can be achieved through different electrochemical techniques. A44 finishes may be over dyed to produce additional colors (A44/A43).
ElectrolysisChemical decomposition of metal surface by the action of dissimilar metals and moisture.
Electrolytic ColoringA multi-step process involving a clear anodizing step, followed by an electrolytic deposition of stable metal compounds at the pore base of the anodic coatings to obtain the color.
Electromagnetic SpectrumThe range of radiant energy
ElevationA drawing of the front, side, or rear of the building drawn to scale. (2) The height above surface of the earth or the vertical distance from a given reference elevation.
ElongationIncrease in length expressed as a percentage of original length. The extension or growth of a material in one direction usually with a shrinkage or reduction in one or both of the other orthographic directions.
Emergency Exit WindowFire escape window (egress window) large enough for a person to climb out. In U.S. building codes, each bedroom must be provided with an exit window. The exact width, area, and height from the floor are specified in the building codes.
Emergency ReleaseA safety device other than panic hardware which permits egress under emergency conditions.
EmissivityThe relative ability of a surface to radiate heat, with emissivity factors ranging from 0.0 (or 0 percent) to 1.0 (or 100 percent).
EmittanceThe ratio of the radiant flux (heat) emitted by a object to that emitted by a blackbody at the same temperature and conditions.
Enclosure WallThe curved wall components of a revolving door.
End DamAny means provided to stop the flow of water out from the ends of the sill, panning system, or subsill and into the wall cavity, such as, but not limited to, sealants, upstands, plates, or gaskets.
Energy PanelA glazed Fenestration Attachment designed to be mounted to the interior or exterior of a primary fenestration product such that a gap is created between the glazing systems of the attachment and the primary fenestration product.
Energy RatingsPerformance ratings. National Fenestration Rating Council (HVRC) measuring windows on their U-Factor, Solar Heat Gain Coefficient, Visible Transmittance, Air Leakage and Condensation Resistance.
ENERGY STAR®An international standard for energy efficient consumer products originated in the United States. It was created in 1992 by the Environmental Protection Agency and the Department of Energy. An Energy Star qualified home uses at least 15% less energy than standard homes built to the 2003 International Residential Code.
English BasementA basement with half its height above grade level.
EntranceThe doorway, vestibule or lobby through which one enters a building.
Entry doorsA doorway that allows entrance to or exit from a building
Environmental ManagementThe organizational structure, planning and resources for developing, implementing and maintaining policy for environmental protection.
Environmental StewardsRefers to responsible use and protection of the natural environment through conservation and sustainable practices. Aldo Leopold (1887–1949) championed environmental stewardship based on a land ethic “dealing with man’s relation to land and to the animals and plants which grow upon it.”
Environmentally FriendlyAlso referred to as environment-friendly, eco-friendly, nature-friendly, and green are marketing terms referring to goods and services, laws, guidelines and policies that inflict reduced, minimal, or no harm upon ecosystems or the environment.
EPAEnivronmental Protection Agency
EPDMA synthetic rubber; Ethylene Propylene Diene Monomer.
Equal LiteEqually sized and spaced sashes.
Equivalent Combined LoadVarious long and short term loads combined into a single load; loads are combined in a manner that considers the variability of glass strength with load duration.
Equivalent Glass AreaTriangular or quadrilateral glass areas interpreted into equivalent rectangular areas for the purpose of determining resistance to loads.
Equivalent Triangular Load Duration (Td)The time duration of the positive phase of a blast pressure pulse idealized as a triangle.
Equivalent WeatherstripManufacturers shall classify their products in groups called Series. Each series defines significant properties of the product group that relate to its component materials, construction, and intended application. Changes in component materials such as yarn, fin, and backing materials that alter the product’s performance or application shall denote a change in series. Changes in a product’s construction such as method of attachment to a base, number of extending fins that alter the product’s performance or application shall also denote a change in series.
Escutcheon PlateA flat ornamental piece of metal for protection and often decoration, around a keyhole, door handle, or light switch.
EucalyptusA fast-growing evergreen Australasian tree that has been widely introduced elsewhere. It is valued for its timber.
Evacuated Glazingreferred to as Vacuum Insulated Glass (VIG). The most thermally efficient gas fill would be no gas at all—a vacuum –in which the space between surfaces two and three is evacuated to a minimum of less than one millionth of normal atmospheric pressure. At that level, there is no conductive or convective heat exchange between the lites of glass, thus lowering the U-factor. – See more at: http://www.aamanet.org/news/2/10/0/all/1086/coming-soon-to-a-window-near-you-vacuum-insulated-glazing#sthash.gIibyqGw.dpuf
Execution And CoordinationBIM model, representing external extents and attributes of fenestration profiles and accessories; and used in coordination, clash detection, sequencing, and other
Expansion JointA separation between building elements that allows independent movement without damage to the assembly.
Exposed SurfacesThose surfaces which are visible when the coated product is installed. These may include both closed and open positions of operating sash, ventilators, doors or panels.
Extensioin CrankA pole, rod or extension used to open and close windows, awnings and skylight that are out of reach.
Extension BoltSee FLUSH BOLT.
Extension JambWooden or vinyl trim that extends the window jamb to match the wall thickness.
ExteriorExposed surfaces visible when viewed from the building exterior with operating sash, door, or ventilators in the closed and locked positions.
Exterior GlazedGlazing infills set from the exterior of the building.
Exterior Insulation And Finish System (Eifs)A non-load-bearing outdoor wall finish system consisting of a thermal insulation board, an attachment systems, a reinforced base coat, exterior joint sealant, and a compatible finish.
Exterior Perimeter SealSealant that seals the joint between the building construction materials, such as masonry, and doors or windows.
Exterior Rain ScreenAn exterior cladding that allows venting to occur for the purpose of controlling water penetration through the system.
Exterior Stain FinishSingle or multi-layered coating system designed to yield a variegated or grained pattern.
Exterior StopThe removable glazing bead that holds the glass or panel in place when it is on the exterior side window. In contrast to an interior stop located on the interior side of the glass.
Exterior SurfaceExposed surfaces visible when viewed from the building exterior with operating sash or ventilators in the closed and locked positions.
Exterior TrimTrim that is installed on the exterior window or door.
Exterior Walking SurfaceFlooring designed to be used outdoors as a component of decks, docks, balconies and stairs.
Extraneous AirAir entering into the monitored/tested area from sources other than the specimen being tested.
Extrud Ability LimitsA set of guidelines established by The Aluminum Association and the Aluminum Extruders Council that provides quality extrusions with standard tooling. Dimensional tolerances, gap-width ratios, extrusion factor and inscribing circle are examples of these limits.
Extruded AluminumAluminum pushed through a die to create a thick and strong type of aluminum profile. Used to make window and sash frame in aluminum window or as cladding for exterior applications on wood windows. In contrast to roll-form aluminum, which is rolled in sheets and much thinner.
Extruded F-RatingFormed by forcing plastic material or metal through a shaped opening.
ExtrusionThe process of producing vinyl or aluminum shapes by forcing heated material through a die.
EyebrowA small and usually short window that is fixed in place or hinged at the bottom and rounded at the top. Usually located on a roof where a dormer would be. Often found on Greek Revival and Italianate houses.



F.S.Federal Specifications
FaçadeThe front of a building.
Face ClearanceThe dimension between the face of a light of glass or panel and the nearest face of its retaining frame of stop, measured normal to the plane of the glass or panel.
Face GlazingOn rabbeted sash without stops, the triangular bead of sealant applied with a glazing knife after bedding, setting and clipping the lite in place.
Face Sealed SystemsA wall system that uses an exterior cladding and sealant or gaskets to control air leakage and water penetration. These components are installed to form an air and water tight seal around the building in the plane of the cladding.
Face ShimSpacer placed between the glass face and the glazing stops to center the glass in the glazing channel.
Facing MaterialThe integrated structural layer of the self adhering flashing.
Failed I.G. UnitAn installed unit failure exhibits permanent material obstruction of vision through the unit due to accumulation of dust, moisture or film on the internal surface of the glass. Surface numbers 2 or 3 in dual-pane units; surface numbers 2, 3, 4 or 5 on triple-pane units.
Falling Weight Impact ResistanceMeasures the resistance of the profile to cracking or breaking during the fabrication processes and general abuse during transportation, storage, installation and use.
Falt- und SchiebetürenGerman: Folding and sliding doors. See Folding Doors
FalttürenGerman: Folding Doors.
FanlightA half-circle window over a door or window, with radiating bars. Also called circle top transom.
FaqadeA face of a building, usually the front.
Feasibility StudyA detailed investigation and analysis conducted to determine the financial, economic, technical or other advisability of a proposed project.
FeeA term used to denote payment for a professional service.
FEMAFederal Emergency Management Agency, the lead agency for overall administration of the NEHRP program.
FenestrationThis term, as used in architecture and construction, refers to the design, construction, or presence of windows, doors, storefront glass and curtain wall in a building. Interestingly, in reference to shipping, it is the practice of placing holes in the rudder of a ship to reduce the work required to move the rudder while preserving its ability to steer the ship.
Fenestration CladdingThe exterior components that cover the frame, sash, leaf, or sliding door panel members and constitute the weather-resistant surface. Some claddings function only as an aesthetic covering, while others contribute partially to the structural strength of the product. This use of cladding should not be confused with the definition of “Components and Cladding – Elements of the building envelope that do not qualify as part of the main wind-force resisting system” as found in ASCE/SEI 7.
Fenestration ProductAny transparent or translucent glazing material plus any associated sash, framer mullions, and/or dividers, in the envelope of a building, including, but not limited to: windows, sliding glass doors, french doors, skylights, curtain walls, and garden windows.
Fenestration SystemCommon types of commercial fenestration systems installed in commercial buildings including windows, curtain wall, window wall, storefront and doors.
Fenestration Testing LaboratoryRefers to either an individual test facility or the collective group of independent testing laboratories that have been inspected and accredited by nationally and internationally recognized governing bodies to perform fenestration test standards.
FensterGerman for Window
Fiber BloomA pultrusion surface condition exhibiting a fiber prominence or fiber show that usually has a white or bleached color and a sparkling appearance as a result of incomplete fiber coverage with resin, or resin removal from the surface by degradation.
Fiber Reinforced ThermosetMaterial in which fibers are blended with resin materials and cured into thermoset composites.
FiberglassA composite material made by embedding glass fibers in a polymer mix. Becoming a common choice in replacement windows.
FichteGerman: Spruce
Field Sound Transmission Class (Fstc)A single number rating system, similar to STC, that is applied to field test data under ASTM E336.
Fillet BeadCaulking or sealant installed at the intersection of two surfaces which meet at an angle, often 90 degrees.
FilmThe clear plastic material placed on glass, and often the frame and sash, to allow temporary protection during construction and installation.
Finger GuardA closure strip of soft material such as rubber or plastic, which is applied at the edge of a door or to the pivot jamb adjacent to door, to prevent damage to hands or fingers inserted between door and frame.
Finger JointA glued joint consisting of a series of interlocking fingers, precision-machined on the ends of two pieces of wood to be jointed.
Finger LiftsSmall holes or indentations on a double hung window’s bottom sash that allow a person to slide the window sash up and down.
Finish HardwareHardware that is within sight.
FirAn evergreen coniferous tree with upright cones and flat needle-shaped leaves, typically arranged in two rows. Firs are an important source of timber and resins.
Fire EnduranceA measure of elapsed time during which a material or assemblage continues to exhibit fire resistance.
Fire ExposureProcess by which or extent to which materials or assemblies are subjected to the conditions created by fire.
Fire-Retardant BarrierA layer of material which, when secured or otherwise interposed between a material and a potential fire source, delays ignition, combustion or other deterioration of the material when the barrier is exposed to fire.
Fire-Test-Response CharacteristicA response characteristic of a mater, or assembly of materials, to a prescribed source of heat or flame, under controlled fire conditions per ASTM E119.
Fixed DoorOne or more non-operable assembled leaves or sliding door panels within a door frame and threshold/sill.
Fixed LightA window which glass is installed directly into non-operating framing members.
Fixed PanelAn inoperable panel of a sliding glass door or slider window.
Fixed WindowType of window that doesn’t open
FlameA hot, usually luminous zone of gas, or particulate matter in gaseous suspension, or both, that is undergoing combustion.
Flame ResistanceThe ability to withstand flame impingement or provide protection from it.
Flange (Frontal Flange)Refers to a type of window which includes a permanent appendage projecting parallel to the plane of the wall, located at or near the exterior surface of the window for the purpose of installing the window against a backstop, buck, receptor or other such stepped features that have been incorporated into the rough opening.
FlankerA window placed to the side of larger center window unit.
Flanking TransmissionSound transmission from the source to the receiving location by a path other than through the test specimen.
FlashingSheet metal, thermo plastic or other material that directs water away from window or door opening. To prevent water seepage or leaks with the purpose of preventing water penetration by draining water away from the window or door to the exterior.
Flashing Systemintegrated system of flashings intended to move incidental water to the building exterior.
Flashing SystemIntegrated system of flashings intended to move incidental water to the building exterior.
Flat GlassA general term covering sheet glass, plate glass, float glass, window glass, and various forms of rolled glass, and named according to the method used in its manufacture. See also , , and SHEET GLASS.
Flexural ModulusThe ratio of nominal stress to corresponding strain below the proportional limit of a material. A constant or coefficient which expresses the degree to which a substance is subject to bending. (The Modulus of Elasticity as determined, by calculation, from a bending test.)
Float GlassGlass formed by a process of floating the molten glass material on a bed of molten metal suchn as tin. It produces a high-quality glass without polishing and grinding.
Float Glasscontact with the tin is known as the tin surface or tin side. The top surface is known as the atmosphere side or air side.
Floor AnchorA metal device attached to the back of a door frame jamb at its base, to secure the frame to the floor. It may be either fixed or adjustable in height.
Floor CheckSee FLOOR CLOSER.
Floor CloserA door closing device which is installed in a recess in the floor below the door to regulate the opening and closing swing of a door.
Floor HingeSee , which is the preferred term.
Floor PivotA center or offset pivot which is located at the floor or threshold.
Floor-to-Ceiling GlassUsed for describing things such as windows that are the full height of a wall
Fluid HeadThe amount of thermal break material which is forced ahead of the filling nozzle. This material promotes complete filling of the cavity and reduces the likelihood of entrapped air bubbles or voids.
Flush BoltA rod or bolt which is mounted flush with the edge or the face of the inactive door of a pair, to lock the door to the frame at head and/or sill. When mounted in the edge, operation is by means of a recessed lever. (See SURFACE BOLT.)
Flush Bolt BacksetThe distance from the outside of the face plate to the inside surface of mounting tabs.
Flush DoorAre simple interior and exterior solid or hollow core doors that feature plain facings on both sides of the construction.
Flush FinA replacement window commonly used in California, where original windows are often aluminum, and exteriors are often stucco. Have large exterior flange to hide the existing window frame.
Flush GlazingA method of setting glass whereby glazing beads are recessed within and flush with the edge of the frame.
FMAFenestration Manufacturers Association
Foam SpacerFoam material with desiccant and high-strength adhesive used instead of a metal spacer to improve insulation.
Fogged UnitA permanent deposit of contaminates on the interior glass surfaces of an insulating glass unit.
FoggingA film on the inside of sealed insulating glass that is the result of a faulty seal.
FoggingA deposit of contamination left on the inside surface of a sealed insulating glass unit due to extremes of temperatures or failed seals.
Folding DoorA door that can fold flat against each other often compared to an accordion. Folding off to the side, these doors are designed to provide quick and easy space divisions and, when open, to provide large clear spaces.
Folding WindowsSimilar to a folding door that folds off to one or both sides in a compact arrangement.
Foot BoltA locking hardware operated by using the foot.
Footcandle (Fc)The units of luminance (amount of light flux) incident on a surface; in this study assumed to be determined at the horizontal work plane (2.5 ft above the floor).
ForceA push or pull action that tends to change the shape of a deformable body or the state of motion of an object.
Force To Latch DoorThe force required to close door and fully engage latch in accordance with Clause [of AAMA/WDMA/CSA 101/I.S.2/A440-111.
Forced Entry Resistance (Fer)The ability of a window or door in the locked position to resist entry under a specified load and conditions.
FoyerThe entrance hall of a house or other building type.
FPMFeet Per Minute
FrameThe fixed frame of a window which holds the sash or casement as well as hardware. The outside perimeter of a window or door consisting of two side jamb members, one head member and one sill member. In a window, the frame will hold the glass lights or sash panels. An assembly of structural members that surround and support the sash, ventilators, doors, panels, or glazing that is installed into an opening in a building envelope or wall.
Frame AreaThis area includes the area of the framing that is in a plane parallel to the infill. This area can be calculated by multiplying the width of the framing systems times its length.
Frame Jamb Primary Material GroupA general category of frame jamb material which is an AAMA approved material type as verified by the frame jamb manufacturer. Aluminum and PVC are separate Frame Jamb Primary Material Groups.
Frame Jamb StructuresThe segment of window frame which provides the pocket and guides the vertical travel of the sash of a complete window.
Frame LinersVinyl or aluminum track assemblies or covers that are fitted into wood window jambs, heads, and sills.
Frame MaterialsThis test will assure the durability of the lamination when exposed to friction loaded cycle testing. Satisfactory completion of this test will qualify the specific frame jamb structure and it’s layered material(s) as a new approved frame jamb material.
Frame SizeWindow unit size, measured from outside edge to outside edge.
Free StandingStructurally independent of an adjacent wall or other background, as a free-standing column.
French CasementA dual operating hinged window, each hinged on the outside edge, with no center post. There is an unobstructed view to the outside when both sashes are open.
French DoorDual hinged doors that open from the middle. Can swing either in or out and have no center post when open.
French Sliding DoorSimilar to a French swing door, but slides open instead of swings.
French WindowTwo sash, each hinged on one stile and opening in the middle.
FrequencyThe number of sound wavelength cycles that occur within one (1) second represented as cycles per second (cps).
Friction Allowance (Fa)An approximation of additional amount of force required to operate the window unit in either direction over and above the weight of the sash and exclusive of breakaway and sash operating force. This force is due to the frictional factors acting on the window unit; the greater the effect of these factors the higher the frictional allowance. The unit of measure for the FA is Newton’s per meter (pounds of force per inch) of sash stile height.
Friction Balance Adjustment (Fba)FBA is an independent friction setting that contributes to the forces that act upon the vertical movement of a sash in an installed window. Balance adjustment instructions shall be specified by the balance manufacturer for use by the window manufacturer.
Friction Balance Rated Capacity (Fbrc)The manufacturer’s specified minimum and maximum weight capacity per balance based upon the Balance Rated Travel Range (BRTR): FBLRC = Friction Balance Lowest Rated Capacity FBHRC = Friction Balance Highest Rated Capacity
Friction Shoe/ClutchA component of a Type 1 balance which uses friction to resist the vertical movement of the sash and provides an engagement location for the pivot pin or pivot bar. The friction shoe/clutch is permitted to provide other functions not related to vertical sash counterbalancing and is available in assorted sizes that suit the pocket size of varied frame designs.
Friction TestA test to determine the maximum amount of resistance attainable by a friction shoe in the pocket of a specific frame jamb structure and geometry. The results of this test may be used to qualify existing and new frame jamb structures and materials with the tested friction shoe.
Front doorsThe main entrance to a house.
FSCForest Stewardship Council (FSC) is an international non-profit, multi-stakeholder organization established in 1993 to promote responsible management of the world’s forests.
FSC Chain of Custody CertificationA certification allows companies to label their FSC products, which in turn enables consumers to identify and choose products that support responsible forest management. 
Full Divided LiteReplication of the True Divided Lite (TDL), with a spacer between the sheets of glass and behind the outside grilles.
Full Frame ReplacementTo replace a window by removing the old window sash and frame down to the studs so the new window, measured to fit the old rough opening, will fit properly.
Full RoundA window in a true round, wheel, shape.
Full Travel RangeThat travel range of the balance from the fully retracted position to the fully extended position.
Fully Tempered GlassGlass that has been heat treated to a high surface and/or edge compression to meet the requirements of ASTM C1048 (kind FT) or CAN/CGSB 12.1. Fully tempered glass, if broken, will fracture into many small pieces (dice) which are more or less cubical. Fully tempered glass is approximately four times stronger than annealed glass of the same thickness when exposed to uniform static pressure loads.
Fusion WeldAlso called a welded corner, it is the process of fusing vinyl iwindow corner pieces together using heat.



Galvanic CorrosionA form of deterioration of metal resulting from the electrochemical reaction that occurs when certain dissimilar metals are in contact with each other in the presence of moisture.
GANAGlass Association of North America
Gas FillA gas other than air, usually argon or krypton, placed between glazing panes to reduce the U-factor by suppressing conduction and convection.
Gas Filled UnitsInsulating glass units with a gas other than air in the air space to decrease the unit’s thermal conductivity U-value and to increase the unit’s sound insulating value.
Gas RetentionThe ability of a sealed insulating glazing unit to retain its original gas-filled composition. In the long term, diffusion through frame and edge-seal materials allows air to progressively replace the original gas(es).
GasketPreformed shapes (strips, grommets, etc.) of rubber or rubber-like composition, used to fill and seal a joint or opening, either alone or in conjunction with a supplemental application of a sealant.
Gasochromic GlazingGlazing which uses the phenomenon of chromism due to tin injection / ejection to color the window. The application of gas flow transporting ions to the surface (catalyst), which changes solar and visible transmittance. See also SWITCHABLE GLAZING.
Gateway Performance RequirementsThe requirements for minimum gateway test size, air leakage resistance, structural design load and overload testing, water penetration testing, forced-entry resistance, and auxiliary testing which are the conditions permitting a product entry into a performance class. They are specifically indicated for each product operator type in Table 12.2 of AAMA/WDMA/CSA 101/LS.2/A440-1L
Gateway Test SizeThe test specimen size specified to enter a performance class.
Gear-Type Rotary OperatorA mechanical operating device for opening and closing projected windows that are not skylights or roof-windows. It consists basically of an operating handle turning an input shaft, which drives a gear mechanism that causes an arm or arms to pivot, operating a window.
Gel TimeThe period of time from the initial mixing of the reactants of a plastic or rubber composition to the time when gelatin occurs, as measured by a specific test. The time in seconds for the mixed thermal barrier material to change from a liquid to a solid including mixing time.
General ConditionsThat written part of the Contract Documents which sets forth many of the rights, responsibilities and relationships of the parties involved.
German WindowsReferred to as German windows, any European window or door is a highly engineered window product consisting of multi-laminated lumber glued up cross-grain to establish long term durability and usability. Clad windows from Europe consist of thick aluminum extrusion offset from the wood to eliminate direct convection and breathability.
GFRCGlass Fiber Reinforced Concrete
GirthFor bent glass, the dimension measured along the curve or bend.
GlassAn inorganic transparent material composed of silica (sand), soda (sodium carbonate), and lime (calcium carbonate) with small quantities of alumina, boric, or magnesia oxides.
Glass DoorA door with no stiles in which glass forms the structure. Provision is made for mounting on hinges or pivots.
Glass FaçadeA facade is generally one exterior side of a building, usually, but not always, the front. It comes from the French word façade which literally means “frontage” or “face”. In architecture, the facade of a building is often the most important aspect from a design standpoint, as it sets the tone for the rest of the building. From the engineering perspective of a building, the facade is also of great importance due to its impact on energy efficiency.
Glass Fiber BoardFibrous glass insulation consisting of inorganic glass fibers formed into rigid boards using a binder.
Glass SizeThe measurement of the complete pane of glass, not just the visible part.
Glass StopA glazing bead which is either applied to, or is an integral part of the frame.
GlazeTo install glass lights or infill material.
Glazed DoorsAny door wth glass panels
Glazed WindowsAny window with glass panels
GlazingThe glass or plastic panes in a window, door, or skylight. Can also refer to the process of fitting the glass into its frame or door panel.
Glazing (N)An infill material such as glass or plastic.
Glazing (V)The process of installing an infill material into a prepared opening in windows, doors, TDDs, roof windows, SSPs or unit skylights.
Glazing BeadA molding or stop around the inside of a window frame to hold the glass in place.
Glazing ChannelChannel into which the glass is inserted and which retains the glass in place.
Glazing Channel WidthThe measurement between the stationary stop and the removable stop.
Glazing CompoundA soft, dough-like material used for filling and sealing the spaces between a light of glass and its surrounding frame and/or stops.
Glazing GasketA preformed elastomeric or plastic material applied between the face of the glass or panel and the framing to provide resilient support between the glass or panel and the framing and to prevent the passage of air and water. Gaskets are normally used alone but in some installations may be used in conjunction with a supplemental application of sealant.
Glazing StopFixed or removable portion of the glazing channel which prevents inward outward movement of the glass edges.
GliderSimply a horizontal sider window.
GothicA style of window commonly found in Gothic architecture that is typically long and narrow with a pointed arch at the top.
Gradient WindThe wind at the top of the atmospheric boundary layer. Wind above the so-called gradient level is not directly influenced by the local surface conditions. In the boundary layer wind tunnel the gradient wind may be referred to as the free-stream wind.
Gray ProfileA profile, the color of which is defined by the color space falling within the parameters LH = 33 to 74, aH = -3 to 4, and bH = -5.5 to 5.5.
GreenhouseA glazed enclosure described by the following criteria: 1. Commercial use or detached from other structures; 2. Not accessible to the public; 3. Exclusively for growing plants; 4. Ridge no more than 20 feet above grade
Greenhouse EffectThe trapping of the sun’s warmth in a planet’s lower atmosphere due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet’s surface.
Greenhouse WindowA three-dimensional window that projects from the exterior wall and usually has glazing on all sides and top; except the bottom, which serves as a shelf.
GrillesVertical and/or horizontal bars that visually divide a pane of glass into sections. Some be detached for ease of cleaning.
Grilles Between GlassEnclosed in the space between panes of glass, they are bars that visually divide the glass.
GrooveLong narrow grooves or depressions in a surface of a pultrusion parallel to its length. Sometimes referred to as a Sink Line or a Sink Mark.
Guard BarA protective bar applied to the lower portion of a door or sidelight to prevent accidental contact with glass.
Guard RailA railing for traffic separation and control.
Gun ConsistencySealant formulated in a softness suitable for application through the nozzle of a caulking gun.
Gun Gray ConsistencyCompound formulated to a degree of viscosity suitable for application through the nozzle of a caulking gun.
Gunnable Foam SealantAn aerosol foam container from which the polymer is extruded through a mechanical dispenser designed for on and off flow at the point of extrusion. A gun- type devise is intended for multiple containers and many re-use cycles.



H Airline CrazeMultiple fine pultrusion surface separation cracks that exceed 6 mm (1/4 in) in length and do not penetrate in depth to the equivalent of a full ply of reinforcement.
HabitableAn area designed to afford living space by virtue of its environmental control using heating and/or air conditioning.
Hair-Line JointThe fine line of contact between abutting members, with a maximum joint width of 1/64”.
Half RoundAlso called half circle, circle top or round top, it is a window with a flat bottom and rounded top. Circle top portion has a height that is half its width.
Half ScreenA screen used on double hung or slider windows to cover just one sash.
HallmarkBy the Window and Door Manufacturers Association (WDMA). Considered a mark of excellence among architects, contractors and other specifiers and is accepted industry-wide.
Hand Of DoorThe designation of direction of swing of door. Viewed in plan, a clockwise swing inward is right hand, and outward is left hand reverse; a counterclockwise swing inward is left hand, and outward is right hand reverse.
Handicap Accessible WindowsAccessibility refers to the design of products, devices, services, or environments for people with disabilities. Therefore, windows can be made to accommodate people with disabilities with well placed hardware, handles and operational function.
Handicap HardwareHardware designed specifically to accommodate the needs of the physically handicapped and to provide for ease of operation of doors and accessibility.
HandingA term to describe the way a door or window opens. Manufactures determine handing by different means and either from the inside or outside so care must be taken when trying to ascertain handing.
HandleA component which enables the movement of a sash, leaf, or panel or which activates a mechanism which locks or unlocks a sash, leaf, or panel.
Handle SetDoor hardware. Includes the interior and exterior door handle or knob, strike plate, turning mechanism, core, spindle and lock plate.
Hard-coat GlassLow-E glass is manufactured by adhering a thin layer of molten tin onto a sheet of glass while the glass is still slightly molten. The tin actually becomes “welded” to the glass. This process makes it difficult or “hard” to scratch or remove the tin. Often this glass has a blueish tint to it.
HardnessResistance to indentation as measured under specific conditions.
HardwareThe mechanisms that allow doors and windows to operate and lock. Includes hinges, locks, keepers, gears, restrictors and handles.
Hardware And Weatherseal “Package”A unique combination of locks, strikes, hinges, operators (push bars, rotos, etc.), limited opening devices, stay bars, friction adjusters, rollers, counter-balances, snubbers, and/or weather seals, used across a range of individual products.
HardwoodWood obtained from deciduous trees, mainly used for finished wood trim, doors, panels, and furniture such as oak, birch, ash, poplar, teak, mahogany, butternut, etc.
HaustürenGerman: House doors
HDG or HANcommon handling service fee by shipper.
HeadThe top horizontal piece of a window or door.
Head BoltA locking device that is mortised vertically on a door.
Head ExpanderAn inverted U-channel installation accessory that may be fitted to the head of a replacement window to accommodate differences between rough opening and window heights.
Head FlashingSheet material, integrated with the water-resistive barrier, that bridges and protects the joint (gap) between the window or door frame members at the head, and the adjacent construction for the purpose of preventing water penetration by draining water away from the window or door.
Head TrackThe top track of a sliding door or sliding window.
HeaderA horizontal load bearing beam used in framing. Jt is placed at the top of a rough opening to support the weight of the wall and roof above.
HeaderA horizontal structural member (beam) that supports the load over an opening, such as that of a door or window. The header transfers that load to the vertical members at the sides of the opening.
Heat Build-UpA temperature rise above ambient air temperature caused by absorption of the sun’s energy. Heat build-up is one of the factors in the dimensional stability of the window assembly.
Heat GainThe transfer of heat from the outside to the inside of a house through conduction, convection and radiation.
Heat LossThe transfer of heat from the inside to the outside of a house by means of conduction, convection and radiation.
Heat Loss RateThe rate at which heat is lost from a system or component of a system, per degree of temperature difference between its average temperature and the average ambient air temperature.
Heat ResistanceMeasures the resistance to surface degradation such as blistering, cracking or delamination. The profile is exposed to a temperature well above the material’s heat distortion temperature in order to predict or accelerate potential surface imperfections that would not be evident otherwise
Heat Strengthened GlassProcess to strengthen glass. Twice as strong as annealed but not as strong as fully tempered. Heat strengthened glass is recommended for hard to reach glass units because any glass manufacturing defects are exposed in the heating furnace and hence don’t become an issue in the building at some later time.
Heat TransferThe movement of thermal energy from one thing to another thing of different temperature. 
Heat-Absorbing GlassWindow glass containing chemicals (with gray, bronze, or blue-green tint) which absorb light and heat radiation, and reduce glare and brightness. See also Tinted glass.
Heating Degree DayTerm used by heating and cooling engineers to refer to the amount of heating requirements of buildings. The base temperature is 65 degrees Fahrenheit. A heating degree day is counted for each degree below 65 degrees reached by the average daily outside temperatures in the winter. For example, if on a given winter day, the daily average temperature outdoors is 30 degrees, then there are 35 degrees below the base temperature of 65 degrees. Thus, there are 35 heating degree days for that day.
Heben SchiebetürGerman: Lift Slide Doors.
Heel BeadSealant applied at the base of a channel, after setting the lite or panel and before the removable stop is installed, to prevent leakage past the stop. Sealant must bridge the gap between the glass and frame.
Hertz (Hz)Dimension of a sound frequency in cycles per second.
High Density PolyethyleneThose linear polyethylene thermoplastics having a standard density of 0.941g/cm3 or greater.
High- Transmission GlassGlass that transmits an exceptionally high percentage of visible light.
High-Cyclic Movement SealantsHigh-cyclic movement sealants are those which have a cyclic movement capability of >12.5%.
HingeMoveable joint or mechanism that allows a window or door to swing open
Hinge BacksetDistance from stop side face of door to edge of hinge cut-out on both door and frame.
Hinged Egress WindowA hinged perimeter frame window assembly consists of any primary window which has passed the applicable performance requirements, in Section 2.1 that is mounted into a stationary perimeter frame and is permanently pivoted or hinged at one jamb to permit
Hinged Glass DoorHinged glass doors consist of one or more glazed panels contained within an overall frame designed so that one or more of the glazed panels are operable. The operable panels swing either to the inside or to the outside (not both). Panels shall be all operable or some operable and some fixed. Panels shall lock or interlock with each other or shall contact a jamb member where the panel is capable of being securely locked.
Hinged Patio DoorsA single or dual paneled patio door. The door panels open from the center and swing either inward or outward.
Hinged Rescue WindowAny window that is mounted into a stationary perimeter frame and is permanently hinged at one jamb.
Hinged WindowsWindows (casement, awning, dual action and hopper) with an operating sash that has hinges on one side. See also Projected window.
Historical DuplicationCustom fabrication of fenestration products to duplicate design elements of years past.
Historische BauelementeGerman: Historical elements
Hold-Back FeatureA mechanism on a latch which serves to hold the latch bolt in a retracted position.
Holz-Aluminium FensterGerman: Wood – aluminum windows.
HolzfensterGerman: Wood windows
Homogeneous MaterialA material in which relevant properties are not a function of the position within the material.
HopperWindow with sash hinged at the bottom.
Horizontal Pivoted WindowSee PIVOTED WINDOW
Horizontal SliderAlso referred to as a gliding window, it is a window in which the one or both sash slides horizontally.
Horizontal Sliding WindowA window that consists of one or more sash that slide or roll horizontally within a common frame, and can also contain fixed lites/sash. Typically, operating sash are identified with an (X) and fixed lites or fixed sash are identified with an
Hot-Applied SealantA sealant that is applied in a molten state and develops properties by cooling to ambient temperature. Also called hot-melt sealant.
House WrapA polymer-based sheet material provided in a variety of dimensions and used as a WRB (the user of this product shall defer to manufacturer’s instructions).
Humidity, AbsoluteThe mass of water vapor per unit of volume.
Humidity, RelativeThe percentage of moisture in the air in relation to the amount of moisture the air
Hung WindowA window consisting of vertically sliding sash which utilize counterbalancing devices to allow the sash to be opened to any variable position between its fully open and fully closed limits. Common types are single hung, double hung, and triple hung. See also VERTICAL SLIDING WINDOW.
Hurricane GlassSee impact resistance
HVACHeating Ventilation and Air Conditioning
Hybrid Tubular Daylighting Device (HTDD)A tubular daylighting device (TDD) whose light transmitting tube consists of more than one material and/or has more than one geometry throughout its length. Typically used with suspended ceilings or to illuminate spaces without ceilings.



IBCAn acronym for International Building Code. A collection of codes published by the International Code Council that covers all buildings except one and two story homes and townhomes up to three stories tall.
ICBOInternational Conference of Building Officials
ICCAn acronym for International Code Council. A national organization that publishes model codes for adoption by states and other agencies. Codes include the International Building Code (IBC) and the International Energy Conservation Code (IECC).
ICC-ESInternational Code Council Evaluation Services, Inc.
IDInside Diameter
IECCAn acronym for the International Energy Conservation Code, which is a publication of the ICC that establishes minimum regulations for energy-efficient structures.
IGMAInsulating Glass Manufacturers Alliance
Impact ResistantThe ability of a material to withstand a high force or shock applied to it over a short period of time.
Impact Resistant GlassWindows utilizing special laminates to offer extra protection. Used in areas prone to hurricanes.
Impact Resistant WindowsA laminated product. There are two main types or residential impact resistant windows, depending on the degree of impact resistance you are looking for.
Impact StrengthResistance to fracture under shock force. The ability of the thermal barrier material to resist breaking, cracking or shattering when subjected to a sudden concentrated load. Impact loads may occur during handling, installation or fabrication of the framing members.
Impaling PinA pin-type device with a sharp point that is used to pierce and retain insulation materials in position.
ImportersThe generic definition to bring merchandise or commodities from a foreign country for sale. However,it is actually more than that. An importer must deal with the shipping, bonds, fees, surcharges, tax, levies, filing fees, duties and filing charges for the product imported. And, with regard to wood windows, must file the Lacey Act paperwork and fees appropriate with the wood species.
ImpulseThe area under the pressure-time history curve with the units of kPa^msec or psnmsec.
InactiveA window or door panel that is secondary and will open only after a primary or active panel is opened first.
Inactive Door Or LeafThe last door of a pair of doors to be released when unlocking, usually the one not equipped with primary lock.
Inactive Multipoint Locking HardwareA lock with at least two lock-points that are driven by a single input.
InclusionAny foreign matter or particles that are either encapsulated or imbedded in the pultrusion.
Industrial WallsWalls composed either of preformed metal sheets made in stock patterns and sizes, used in combination with standard windows, or of large metal-faced insulated panels, used either with or without fenestration. Typical usage of such walls is on industrial type structures.
Industry Foundation Classes (Ifcs)IFCs define how “things” such as structure, doors, walls and fans (as well as abstract concepts) should be described so that different software packages can use the same information.
Inert GasRefers to the use of chemically nonreactive gas(es) within the cavity of a sealed insulating glass unit for the purpose of reducing conductive/convective heat transfer.
InfillVarious material glazed into a framing system.
InfiltrationA term that describes the air or water that moves between the inside and outside of a building. See air leakage.
Infrared RadiationInvisible, electromagnetic radiation beyond red light on the spectrum, with wavelengths greater than 0.7 microns.
InoperableNo longer opening, closing, locking or unlocking as originally designed.
InorganicDesignating or composed of matter that is not animal or vegetable; designating or composed of any chemical compound not classified as organic. Most inorganic compounds do not contain carbon and are derived from mineral sources.
Insect ScreenA mesh made of metal wire, fiberglass, or other synthetic fiber material attached to a frame. Sllows ventilation when a window is opened, while still keeping insects outside.
Insert ReplacementA replacement window that utilizes use of the original frame.
Inside RadiusThe distance from the center of the unit to the inside of the revolving door drum.
Inside StopA thin, vertical piece of wood that keeps the sash in place.
InstallThe term “install” is used to describe operations at project site including the actual “unloading, unpacking, assembly, erection, placing, anchoring, applying, working to dimension, finishing, curing, protecting, cleaning, and similar operations.”
Installation AccessoriesComponents supplied by the fenestration manufacturer that are specifically designed to mate or “trim out” the product with various surrounding constructions.
Installation HolesHoles in window or door frames that are fabricated by the manufacturer to locate and accommodate installation fasteners.
Installation MastersAn AAMA backed intensive training and certification program that incorporates industry-accepted best practices for proper installation of fenestration products industry wide.
InstallerAn “Installer” is the Contractor or an entity engaged by the Contractor, either as an employee, subcontractor, or sub-subcontractor, for performance of a particular construction activity, including installation, erection, application, and similar operations.
Insulated ShuttersInsulating panels that cover a window opening to reduce heat loss.
Insulating GlassTwo or more pieces of glass spaced apart and hermetically sealed to form a single glazed unit with one or more air spaces in between. Also called double glazing.
Insulating ValueSee U-factor.
InsulationConstruction materials used for protection from noise, heat, cold or fire.
Insulation Rating (Ul)/T-Rating (Opl)A measure of the perimeter fire containment system’s resistance to both flame passage and heat transfer and requires the maximum temperature rise on the unexposed surface of the fill material or on the interior surface of the curtain wall 25 mm (1 in) above the fill material not to exceed 163°C (325°F)above the starting temperature. For perimeter fire containment systems having a clearance distance of 150 mm (6 in) [100 mm (4 in) for the T-Rating] or greater between the curtain wall and the floor, the Insulation Rating also requires the average temperature rise on the unexposed surface of the fill material not to exceed 121°C (250°F) above the starting temperature.
InswingDoors or windows with panels that swing inward.
Integral Color Anodic FinishesCoatings are formed in special electrolytes that produce colors in the aluminum oxide coating as it forms. A range of colors from light to dark bronze and black is achieved with this process.
Integral FinSee Mounting Flange.
Integral MullionA horizontal or vertical member which is bound at either end or both ends by crossing frame members.
Integral Ventilating System/DeviceAn apparatus that is independent from but installed into a window, door, or unit skylight product for the purpose of controlling the transfer of air through the window, door, or unit skylight product.
Integration Of The AssemblyIn a wall assembly the flashing needs to be properly integrated with the water resistive barrier (WRB). Together with the facing material, the integrated flashing and WRB form a weather resistive integrated system.
Integrity Rating (Ul)/F-Rating (Opl)A measure of the perimeter fire containment system’s ability to withstand the fire exposure test without permitting the passage of flame through openings or the occurrence of flaming on an element of the unexposed surface of the fill material or floor or on the interior surface of the curtain wall above the fill material.
InteriorExposed surfaces visible when viewed from the building interior with operating sash, doors, or ventilators in the closed and locked position.
Interior Accessory WindowA glazed frame and/or sash, attached inboard of existing prime windows, curtain wall, or storefront, in commercial buildings, to enhance control of themal transmittance, solar heat gain, sound, air leakage, and/or daylight. IAWs are not intended for occupant operation or to be used with the exterior windows in the nor are they intended to provide any specific resistance to air leakage or water penetration, or withstand structural load.
Interior CasingInterior trim around a door or window.
Interior DoorA door system not intended for use in exterior applications.
Interior GlazedGlazing infills set from the interior of the building.
Interior Glazing DepthThe measurement from the bottom of the glazing channel to the top of its stops.
Interior GrillsAluminum grilles that are sealed in the airspace of a double or triple paned glass unit.
Interior StopThe removable molding or bead located on the interior side that holds the lite or panel in place. (See .)
Interior WindowA window system not intended for use in exterior applications.
InterlayerA layer of material acting as an adhesive between layers of glazing.
InterlockThe encounter location where two adjacent sliding doors or gliding windows connect.
InterlockerAn upright frame member of a panel in a sliding glass door or sliding window which engages with a corresponding member in an adjacent panel when the units is closed. Also called interlocking stile.
Intermediate PivotA jamb mounted alignment and/or reinforcing offset pivot located between the top and bottom offset pivots on a door.
Internal LoadsLoads from pressures within a building; this may be stack pressures, pressures from air conditioning fans, or pressures caused by air infiltration.
Internal MuntinsDecorative grid installed between the glass lites that do not actually divide the glass.
IRCAn acronym for the International Residential Code, a publication of the ICC that outlines codes for single-family homes, and low-rise multi-family buildings.
IsocyanateAn organic compound having at least one isocyan group united with an oxygen (NCO).
Isocyanate ComponentOne of the two components of a thermal break system. Normally in this application, it is a polymeric isocyanate or a blend of materials whose major component is an isocyanate.
Isolation CoatingA material that separates two adjacent materials to prevent galvanic corrosion of one of the materials by the other material.
IWCInches of Water Column (also iwc)
IzodimpactorA machine designed for the testing of the impact resistance of materials such that the specimen is held as a vertical cantilever beam and is broken by a single swing of a pendulum with the line of initial contact at a fixed distance from the specimen clamp and from the centerline of the notch and on the same face as the notch as described in ASTM D256.



Jack StudA block or short stud nailed to the rough door or window studding to add strength and to provide a solid bearing for the lintel and nailing member for the finished door jamb or window frame.
Jal-AwningA window consisting of a multiplicity of top-hinged sash arranged in a vertical series within a common frame, each operated by its own control device which
JalousieWindow made up of several horizontally-mounted glass slats that fit together tightly when closed and rotate outward when cranked open.
JambWidth of the window frame from the inside to the outside. Vertical pieces are called side jambs. Horizontal top pieces are called head jambs. Horizontal bottom pieces are called sills.
Jamb AnchorA metal device inserted in the back of a metal frame to anchor the frame to the wall. A masonry anchor is used in masonry wall, a stud anchor in a wall built with wood or metal studs.
Jamb ClipsUsed in replacement window installation or for windows and doors that do not have a nailing flange. They are the metal brackets that secure the window jamb to the stud next to the window opening.
Jamb DepthThe measurement of the window or door from the inside of the exterior trim to the inside of the interior trim.
Jamb ExtensionA piece that is added to the window jamb to match the wall’s thickness.
Jamb FlashingSheet material, integrated with the weather-resistive barrier, that bridges and protects the joint (gap) between the window or door frame members at the jambs, and the adjacent construction for the purpose of preventing water penetration by draining water away from the window or door.
Jamb LinerUsed to make a window fit properly within a frame. In modern replacement windows, it contains the track on which a double-hung window sash slides.
Jambliner SystemConsists of rigid structural members that mount in the jambs of a typical wood­framed hung window and have, as part, a set of installed sash balances. Sash Balances that are designed for exclusive use in jambliner systems rely on the friction between the sash stiles and the jambliner surfaces to hold the sash in a stationary position throughout sash travel.
J-ChannelA cosmetic piece used as an interface between exterior siding and a window for a finished appearance.
JointThe space or opening between two or more adjoining surfaces.
JoistThe sub-deck structural element located directly beneath the plank system.
Joist SpacingThe distance between the center of each joist, commonly 16” or 24”.



KastendoppelfensterGerman: Box double window
KD UnitA KD unit is shipped in a disassembled condition and later assembled according to the instructions of the manufacturer utilizing all of the components supplied or specified by the manufacturer.
KeeperSash hardware that the lock arm engages.
KertA narrow slot cut in to the face of a material such as wood or metal.
Keyed-Alike CylindersCylinders operated by the same key. (Not to be confused with master-keyed cylinders.)
Keyed-Different CylindersCylinders requiring individual keys for their operation.
Kick PlateA plate applied to the face of the bottom of a door or sidelight to protect against abrasion or impact loads or to maintain sight lines.
KieferGerman: Pine
King PostThe vertical member at the center of a triangular truss.
King StudThe full length stud next to a door or window opening to which the trimmer and lintel are nailed.
Kipp FensterGerman: Tilt window
Knife ConsistencyCompound formulated to a degree of firmness suitable for application with a glazing knife such as used for face glazing and other sealant applications.
KnobA round handle for actuating a locking or latching device.
Knocked Down (KD)A system that is sold a kit for assembly on site.
KryptonAn inert, nontoxic gas used in insulating windows to reduce heat transfer.
KWHKilowatt Hour. Unit of energy or work equal to one thousand watt-hours expended over one hour.



LaitanceAn accumulation of fine particles on the surface of fresh concrete due to an upward movement of excess water.
LaminateA layer of film or veneer applied to the surface of the profile.
Laminated GlassTwo or more sheets of glass with an inner layer of transparent plastic, typically of polyvinyl butyral (PVB) or ethylene-vinyl acetate (EVA), sandwiched together under heat and pressure to which the glass adheres if broken. Used for safety glazing and sound reduction.
LarcheGerman: Larch. A conifer similar to fir.
LatchA mechanism having a spring-activated beveled latch bolt but no locking device. Retraction of the latch bolt is by lever handle or knob.
LatexA colloidal dispersion of a rubber resin (synthetic or natural) in water and which coagulates on exposure to air.
Lead Compound ContentThe percentage by weight of lead or lead compounds in formulations used to make profiles. Restrictions on lead content are meant to ensure that compounds do not contain lead in excess of United States Safety Standards.
Lead ContentInsures that compounds do not contain lead in excess of United States safety standards
Lead glassLead glass is a variety of glass in which lead replaces the calcium content of a typical potash glass.
LeafA part of a side-hinged door system, glazed or unglazed, surrounded by a frame. Leaves can be fixed in place (inoperable) or movable (operable).
LED lighted glassThermal pane glass with LED lights inside the thermal pane. Used to back light art glass or beveled glass. Recommended use for doors and bay/bow windows.
LEEDAn acronym for Leadership in Energy and Environmental Design. The LEED rating system offers four certification levels for new construction — Certified, Silver, Gold and Platinum — that correspond to the number of credits accrued in five green design categories: sustainable sites, water efficiency, energy and atmosphere, materials and resources and indoor environmental quality. By fulfilling credits, projects earn points that determine its certification level: Certified (40-49 points), Silver (50-59 points), Gold (60-79 points) and Platinum (80+).
LEED CertificationStands for Leadership in Energy and Environmental Design, is a certification program focused primarily on new, commercial-building projects and based upon a points system. The more points you earn, the higher your rating.
Letter SlotSee MAIL SLOT.
LevelHaving a horizontally flat, even surface with no irregularities and no vertical tilt. No part of the surface is higher or lower than any other part.
Lever HandleA bar-like grip which is rotated about an axis at one of its ends to operate a latch.
Lever-Type OperatorA mechanical operating device for opening and closing project-out windows that are not skylights or roof-windows. It consists basically of a bar-like operating mechanism that is used to push open and pull closed the sash portion of an operable window.
Life Cycle AssessmentReferred to “LCA”. Is a multi-step procedure for calculating the lifetime environmental impact of a product or service. The complete process of LCA includes goal and scope definition, inventory analysis, impact assessment, and interpretation.
LiftHandle for raising the lower sash in a double-hung window. Also called sash lift.
Lift And Slide HardwareHardware used in a sliding door or horizontal sliding window application that lifts a sliding sash/panel vertically before the sash/panel can be moved horizontally.
Lift RailA horizontal member applied to the top or bottom of the glass and used to operate the sash.
Lift Slide DoorsPrimarily used for very large and heavy doors. The hardware, when activated, lifts the massive sash off and away from other components as a way to reduce friction when opening. Typically can be made up to 22′ wide as a two panel door. French style double doors also available as a lift slide door.
LightA window; a pane of glass within a window. Double-hung windows are designated by the number of lights in upper and lower sash, as in six-over-six. Also spelled informally lite.
Light Brown ProfileA profile, the color of which is defined by the color space falling within the parameters of LH = 33 to 61, aH = -1.5 to 12.5, and bH = 3.0 to 12.5.
Light Green ProfileColor defined by the color space falling within the parameters LH = 45 to 80.5; aH = -25 to -3; bH = 1 to 14.
Light or LiteOne piece of glazing. Another term for a pane of glass used in a window.
Light Reducing GlassGlass formulated to reduce the transmission of visible light.
Light ShaftA shaft that extends from a roof window, through the attic, to light a room.
Light WellAn open area within a building or in a subsoil space around a basement window, which provides light and air.
Lighting PowerThe lighting power load including the lamp, density ballast and controls (in watts) associated with a given space area (in square feet); the units are power per unit area, or watts per square foot (w/s.f.).
Light-to-Solar-Gain RatioA measure of the ability of a glazing to provide light without excessive solar heat gain. It is the ratio between the visible transmittance (VT) of a glazing and its solar heat gain coefficient (SHGC). Abbreviated LSG.
Limited Travel RangeAny range within the Full Travel Range. The limits of this range shall be measured from the point of full retraction as specified by the balance manufacturer.
Limited Water (Lw)The water penetration resistance performance is achieved by testing at a pressure less than the minimum test pressure required for the indicated performance class and performance grade (design pressure).
LinealAn stock length of window material that is used to make window or door components.
Linear-Type OperatorA mechanical operating device for opening and closing projected windows that are not skylights or roof-windows. It consists basically of an operating handle turning an input shaft, which drives a gear mechanism that causes an arm to move linearly, operating a window.
LintelA piece of wood, stone, or steel placed horizontally across the top of door and window openings to support the wall above the opening. Also called a Header.
Liquid Applied FlashingA material that is fluid at the time of application that provides a water-resistive seal around building openings at or near the interface between the through-wall penetration and the building envelope.
Liquid Applied Water Resistive Coating/SealantA product applied to a surface in a liquid/fluid state to improve the water resistance of the substrate and interfaces with that substrate.
Liquid Crystal GlazingLaminated glass that can change from clear to diffused through the use of liquid crystals, controlled by an electrical current.
ListedTo be included in a list published by a HUD approved certification program.
LiteAn individual pane of glass in a window or door.
Live LoadThat part of the total load on structural members that is not a permanent part of the structure. it may be variable, as in the case of loads contributed by people, furniture, wind, snow or earthquake loads.
LockHardware for keeping a door or window securely fastened.
Lock BacksetDistance from vertical centerline of leading edge of lock stile of door to centerline of lock cylinder, measured parallel with door face.
Lock FaceplateThe exposed plate which sets in the edge of a door to cover a locking mechanism.
LocksetHardware for securing a door. Includes inside and outside door handles, keys, latch bolt, dead bolt, strike plate, and other parts.
Lock-Strip GasketA gasket in which sealant pressure is attained by inserting a keyed locking strip into a mating keyed groove in one face of the gasket. Also called a structural gasket.
Long-Wave Infrared RadiationInvisible radiation, beyond red light on the electromagnetic spectrum (above 3.5 micro meters). Emitted by warm surfaces such as a body at room temperature radiating to a cold window surface.
Low Emissivity GlassGlass with a transparent metallic or metallic oxide coating applied onto or into a glass surface, which reflects long-wave infrared energy and thus improves the U- value.
Low Emittance (Low-E) CoatingA coating that has a reduced ability to radiate heat energy; when facing an airspace this property reduces the amount of heat transfer across the space.
Low-Conductance SpacersMaterial placed between panes of glass designed to reduce heat transfer at the edge of an insulating window. Spacers are placed between the panes of glass in a double- or triple-glazed window.
Low-Cyclic Movement SealantsLow-cyclic movement sealants are those having minimum movement capability through their useful life in mechanically restricted joints.
Low-E GlassShort for low emissivity glass. It refers to a type of coated glass to offer better UV protection and energy efficiency.
Low-Emittance (Low-E) CoatingMicroscopically thin, virtually invisible, metal or metallic oxide layers deposited on a glazing surface primarily to reduce the U-factor. The coatings let visible light pass through the glazing, while reflecting radiant infrared energy.
Lumber YardA business that sells building materials for construction and home improvement related uses. Often also provide planning services and drafting details.



MAF RatioThe manually applied force (MAF) divided by the Test Weight.
MahoganyHard reddish-brown timber from a tropical tree, used for high-quality wood products.
Mail SlotAn opening provided in a door, sidelight or adjacent construction for the insertion of mail. (Size and location usually governed by the Postal Code.)
Manually Applied Force (Maf)That externally applied force required to cause movement of the guide block when a balance is mounted in the test apparatus with test weight attached.
Manually Applied Force Ratio (Mafr)The ratio of the maximum MAF to test weight (See Sections 8.4.4 and 8.4.5 of AAMA 902).
Manufactured HomeA dwelling, other than site built, constructed in accordance with Federal Manufactured Home Construction and Safety Standards/24 CFR 3280 and 24 CFR 3282.
ManufacturerA company which fabricates and/or assembles one or more parts, components, and/or accessories or supplies entire fenestration systems.
Masonry ClipA clip that allows an installer to mount a replacement window to existing brick, concrete, wood or metal walls.
Masonry OpeningA brick, stone or stucco opening.
Mass LawA rule of sound attenuation stating that the sound transmission loss across a barrier will increase approximately 6 decibels for every doubling of the barrier’s mass per projected unit area.
Master FramePrimary structural system containing sub-assemblies which shall be attached to a manufactured home wall.
Master KeyA key to operate cylinders, each of which may be set to an individual key.
MasticA material composition that, after application as a thin layer, is converted to a solid protective, or decorative, or functional adherent film.
Material ChangesVariations in the composition of approved frame jamb primary material groups (PVC, aluminum) that influence the pocket inner wall surfaces or structural characteristics will be considered new frame jamb structures. Material composition variations of frame jamb primary material groups for purposes of material stability, resistance to exposure, service for life, color changes and enhancements for processing shall not constitute a material change. Significant material changes that are indicated, but not itemized by the frame jamb manufacturer may be specifically referenced by the manufacturer’s product series identification of the frame jamb.
Material Flow AnalysisMFA is an important tool to study the bio-physical aspects of human activity on different spatial and temporal scales.
Material Safety Data Sheet (MSDS)Data for evaluating hazards, toxicity and proper handling of chemicals are furnished by thermal break suppliers in the form of a MSDS.
Maximum Capable EventThe maximum intensity of earthquake ground shaking that may ever be expected at the building site within the known geological framework. In areas on NEHRP maps with an Aa (acceleration coefficient) value of 0.3 or greater, this ground shaking intensity may be taken as the level of earthquake ground motion that has a 98 percent change of non-excedance in 50 years, or an average return period of 2,500 years. This event has also been termed a “Maximum Credible Earthquake,” and, most recently (1997 NEHRP “Provisions”) a “Maximum Considered Event.”
MDFAn acronym for medium-density fiberboard. An engineered wood product used in doors and trim.
Mechanical FasteningThe method employed to join together two or more components of a window using a mechanical device such as a screw, rivet, etc.
Mechanical WindowA window with corners mechanically screwed, as opposed to a welded, together.
Mechanically Attached FlashingFlashing which is permanently attached using screws, staples or other mechanical fasteners.
Mechanic’s LienA legal charge on property in favor of persons supplying labor or materials for a building for the value of labor or materials supplied by them. Clear title to the claim for the labor, materials or professional services is settled through the “release of liens” which is accomplished through a form given to the owner by the contractor.
Medium StileSee STILE.
Medium-Cyclic Movement SealantsMedium-cyclic movement sealants are those having a cyclic movement capability of >5% to 12.5% through their useful life.
Meeting RailThe horizontal part of a hung window where two panels meet and create a weather barrier.
Meeting StileA vertical part of a sliding glass door or a sliding window that meets to fill the opening between the sash when the sash are closed.
Meeting StileOne of the two adjacent vertical leaf, sash or panel members that come together when in the closed position.
Membrane Drainage SystemA wall system in which the first (exterior) building surface is considered cosmetic and not the sole method of protecting the building from moisture, e.g., stucco, brick veneer, or siding. The waterproofing and weatherability of the fenestration product is integrated into the system and is waterproofed and sealed to a surface behind the first (exterior) building surface. The fenestration product is usually integrated (sealed) to an underlayment membrane or flashing system not exposed to the weather. Moisture collected at the underlayment membrane or flashing is drained to the exterior at the bottom-most locations of each floor, story, or level.
MerantiThe soft weak light usually pinkish to dark red wood of various trees of the genera Hopea and Shorea of Malaysia, Borneo, and the Philippines that is sometimes substituted for mahogany in cabinetwork
MerantiDark Red Meranti is sometimes referred to as Red Lauan, and very commonly used in southeast Asia. Also called Philippine Mahogany but Meranti bears no relation to what is considered to be “true” mahogany. A meranti tree can reach a 200′ height and a trunk diameter of 6′. A lumberman’s dream, it will also be branch free for 90′.
MetadataThe collection of attributes associated with a particular object.
Metal Curtain WallAn exterior curtain wall which may consist entirely or principally of metal, or may be a combination of metal, glass and other surfacing materials supported by or within a metal framework.
Metal SpacersRoll-formed metal shapes used at the edges of an insulating glass unit to provide the desired spacing of the glasses; metal spacers allow areas for sealant applications and contain desiccants.
Metal-Clad WindowsExterior wood parts covered with roll formed or extruded aluminum, copper, bronze or vinyl as a protect from the elements.
Methylene ChlorideSolvent formerly used for cleaning and flushing thermal break compounds from the nozzles and operating parts of the mixing and filling machine. (Suspected of being an animal carcinogen.)
MicronOne millionth (10-6) of a metric meter.
MigrationSpreading or creeping of oil or vehicle from a sealant out onto adjacent non-porous surfaces. (See BLEEDING.)
MilOne thousandth of an inch, or 0.0254 millimeter.
Mill ConstructionA type of “slow-burning” construction made of masonry walls, heavy timber framing, and planked or laminated wood floors.
Mill FinishesUncoated aluminum that possesses a silvery, natural finish. This finish protects aluminum against most atmospheric corrosion. Atmospheric or certain job-site conditions may affect the surface appearance of mill finish aluminum.
MillworkDoors, windows and door frames, mantels, panel work, stairways, and woodwork.
Mineral Fiber BoardA fibrous insulation board composed of either inorganic glass fibers or inorganic steel slag or rock fibers, bonded together using a binder. Commonly, however, this term is used and understood to mean slag wool.
Minimum Gateway Test SizeThe test specimen size specified to enter a performance class at the lowest or minimum level.
MiterMost commonly, a joint made by joining together two 45 degree bevels.
Mitered CornersUsually a 45-degree mitered joint produced in some sash where vertical jamb members meet horizontal head and sill members.
Mixing RatioAmount of resin component with respect to the isocyanate component present in the thermal break material measured either by volume or by weight.
Model Building CodeA construction code developed from input from industry, building officials, and others for use as a guide for the development of state and local building codes. Model building codes have no legislative or jurisdictional power.
Model Energy Code (MEC)The Model Energy Code is cited in the 1992 U.S. Energy Policy Act (Epact) as the baseline for residential Energy Codes in the United States. It has been succeeded by the International Energy Conservation Code (IECC) published by the International Code Council (ICC). It contains energy efficiency criteria for residential and commercial buildings.
Model ServerModel servers allow centralized storage of IFC information models, allowing them to be accessed and modified via the Internet, and manipulated by a large audience over the building’s lifecycle.
Modular Opening“M.O.” Callout opening.
Modular Size “M.S.” Callout size.
ModulusStress at a given strain, or tensile strength at given elongation.
Modulus of ElasticityThe ratio of stress to strain, being an indicator of a material’s bending resistance to a load.
Moisture BarrierA layer of material used to retard or prevent the absorption of moisture into a construction.
Moisture ContentThe percentage of dry weight that is composed of water, such as in wood.
Moisture PenetrationMoisture migration between the glass and interlayer which may cause hazing or other discoloration of the interlayer. Normally, this will not be a cause for rejection.
Moisture Vapor Transmission Rate (Mvtr)The rate at which moisture vapor permeates through a polymer film.
MoldingA strip of wood or other material having a rounded or otherwise decorative surface; used to conceal joints or to accent and highlight other surfaces.
Monolithic GlassA single lite of glass.
MortiseA hole or rectangular slot that is cut into a piece of wood to be fitted with a corresponding Tenon.
Mortise LockA lock to be inserted edgewise in the stile of the door.
Mortise TypeWhich has a threaded surface which screws directly into a lock case, with a cam which engages the lock mechanism.
Mortise-and-TenonA type of woodworking joint that is simple and strong. Formed mortise is cut in one piece of wood and is fitted with another piece of wood called the Tenon.
Mounting DistanceThe distance from the bottom of the weatherstrip backing to an opposite mating surface.
Mounting FlangeA permanently attached appendage protruding from the body of a window or door. It is used as either an installation attachment feature or part of the weather barrier interface between the product and the wall, or both. (Also known as Integral Mounting Flange or Nail Fin.)
Mounting SurfaceThe exterior surface(s) of the pre-existing window frame.
MPFMerchandise processing fee assessed by US Customs
Mull CoverThe connecting cover of two windows assembled in tandem.
MulledWhere two windows are joined together at the mullion.
Mulled Fenestration AssemblyAn assembly of two or more individual products that will be installed in a single rough opening (individual products are those primary or dual windows, or primary sliding glass doors as defined herein). Mullion elements may be horizontal, vertical, or both.
MullingWhen two or more windows are joined together, either vertically or horizontally.
MullionA major structural piece joining two windows, which can run vertically or horizontally.
Mullion ElementsOne or more of the following: 1)Reinforced or non-reinforced frame member(s) 2)Reinforced or non-reinforced mullion member(s) 3)Additional independent reinforcement shapes.
Mullion StiffenerAn additional reinforcing member used in a reinforcing mullion. Mullion stiffeners carry the entire wind load or share the load with adjacent frame members.
Mullion, CombinationA horizontal or vertical member formed by joining two or more individual fenestration units together without a mullion stiffener.
Mullion, IntegralA horizontal and/or vertical member which is bounded at either end or both ends by crossing frame members.
Mullion, ReinforcingA horizontal or vertical member with an added continuous mullion stiffener and joining two or more individual fenestration units along the sides of the mullion stiffener.
Multi-Bar HingeA mechanical device which, when mounted in a window in accordance with the manufacturer’s instructions, is used to support a variety of in-plane sash types; such as, project-out (at bottom), project-in (at top), casement (out-swinging or in­swinging), parallel opening (four sides of sash opening outward) and certain types of sash which are opened primarily for glass cleaning.
Multi-LayerFrame materials that have laminated or applied, multi-layer structure within the frame pocket must qualify with complete testing according to 8.1 through
Multiple Glazing Panel (Mgp)A glazed panel that can be installed in or on a sash, leaf, or panel on either the interior side or exterior side of the primary glazing. An MGP is tested only in conjunction with a specific primary window or door.
Multiple-Glazed UnitsUnits of three glass lites (triple glazed) or four glass lites (quadruple glazed) with two and three air spaces respectively.
Multi-Point HardwareA lock assembly featuring two or more locking points other than the combination of one latch bolt and one deadbolt. Multipoint hardware typically features one latch bolt, one deadbolt, and additional auxiliary locking points.
Multipoint LockA lock that secures the window or door at several or multiple locations and which simultaneously lock into place through the action of a continuous travel drive rail.
MuntinA secondary framing member (horizontal, vertical, or diagonal) to hold the window panes in the sash. This term is often confused with mullion.
Muntin BarsAlso called grilles or muntin grills, muntins are bars that separate glass into a decorative pattern.



NAHBNational Association of Home Builders
Nailing FinAn accessory, through which a window is nailed in place to the structure of the building.
Natural ConvectionA heat transfer process involving motion in a fluid (such as air) that is caused by a difference in the density of the fluid and the action of gravity. This is an important part of heat transfer from the glass surface to room air.
Needle GlazingApplication of a small bead of sealant / compound at the site line by a nozzle gun.
Negative PressurePressure acting in the outward direction.
NEHRPNational Earthquake Hazards Reduction Program. It was developed in response to the Earthquake Hazard Reduction Act of 1977. The principal agencies involved in the NEHRP are: FEMA – Federal Emergency Management Agency, the lead agency for overall administration of the NEHRP program. NSF – National Science Foundation, which supports academic research studying all aspects of the earthquake hazard problem. NIST – National Institute for Standards and Technology (formerly the National Bureau of Standards), which supports standardization activities, including those related to building construction. USGS – United States Geological Survey, which studies and defines earthquake hazards from the seismological and geological points of view; produces the base maps for seismic hazard.
NeopreneA synthetic rubber having physical properties closely resembling those of natural rubber. It is made by polymerizing chloroprene, and the latter is produced from acetylene and hydrogen chloride.
Net ZeroAlso known as a zero net energy (ZNE) building, net-zero energy building (NZEB), or net zero building, is a building with zero net energy consumption, meaning the total amount of energy used by the building on an annual basis is roughly equal to the amount of renewable energy created on the site
New Construction WindowsNew construction windows involve installing the window prior to exterior waterproofing and finishes. Comes with a new frame of proper jamb thickness or with extension jamb accessories.
New Frame Jamb StructuresA frame jamb structure that has variation(s) in material composition and/or design geometry to the inner pocket walls of previously approved frame jamb structures.
New InstallationInstallation of a fenestration product in a new building or wall.
NFPANational Fire Protection Association
NFRCThis acronym stands for the “National Fenestration Rating Council”. This independent organization is a non-profit that certifies windows, doors and skylights for energy efficiency.
NFVNet Free Venting
NGANational Glass Association
NIBSNational Institute of Building Sciences
NISTNational Institute for Standards and Technology (formerly the National Bureau of Standards), which supports standardization activities, including those related to building construction.
Noise Reduction (Nr)The difference between the Sound Pressure Level on each side of a barrier for a given measured frequency.
Non-CombustibleWill not combust.
Non-DryingA sealant that does not set up or cure.
Non-FinA fenestration product that has no integral appendage attached to the body of the window or door for the purposes of installation or air/water resistance. Also called Block Frame.
Non-HabitableAn area designed to afford living space on a less than year-round basis by virtue of its lack of environmental or temperature control systems. Non habitable space is designed to serve as recreational space on a seasonal basis.
Non-Hung WindowA window consisting of vertically sliding sash which utilize mechanical retainers or slide bolts to allow the sash to be opened to any one of the pre-selected positions between its fully open and fully closed limits.
Non-Integral Door Bottom WeathersealA door bottom weatherseal which can be readily removed from an assembled and installed door product which is not an integral part of a door panel.
Non-Keyed CylinderFor inactive doors. It is a door handle that has no key and cannot be locked from the outside.
Non-OperableIntended to not open or close.
Non-Resilient TapeA high solids content, mastic material furnished in varying thicknesses and widths, in a roll form; easily deformed and permanently soft and tacky.
Non-SagA sealant formulation having a consistency that will permit application in vertical joints without appreciable sagging or slumping. A performance characteristic which allows the sealant to be installed in a sloped or vertical joint application without appreciable sagging or slumping (thixotropy).
Non-SkinningA product that does not form a surface skin after application, and usually remains tacky or sticky.
Non-StainingCharacteristic of a compound which will not stain a surface.
Non-VolatileAny substance which does not evaporate or volatilize under normal conditions of temperature and pressure.
Normal Use(Pertaining to windows, doors, secondary storm products, operable unit skylights, and roof windows) Intended for operation for reasons in addition to cleaning and maintenance of the window(s), door(s), operable unit skylight(s), or roof window(s) in question.
NozzleThe tubular tip of a caulking gun through which the compound is extruded.
Nozzle SettingAdjustment to the filling machine to control the rate of flow of the thermal break material into the cavity and maintain the proper fluid head during filling.
NPEANational Patio Enclosure Association
NSANational Sunroom Association
NSFNational Science Foundation, which supports academic research studying all aspects of the earthquake hazard problem.
NWWDAThis acronym stands for stands for National Wood Window and Door Association, now called the Window and Door Manufacturers Association (WDMA). It is a trade organization for standards in wood window and door manufacturing.



O.C.On Center
OakOaks are common in many north temperate forests and are an important source of hard and durable wood used chiefly in construction, furniture, and (formerly) shipbuilding.
Obscure GlassAny textured glass (frosted, etched, fluted, ground, etc.) used for privacy, light diffusion, or decorative effects.
OCFOne component foam that is the same as aerosol foam sealant.
Octagon WindowsA window having eight angles and eight sides. Defined as specialty windows and are often used in the design of high-end homes to achieve a classical look.
ODOutside Diameter
Off-CenternessThe distances between the respective center-lines of the pile and the overall width evidenced by uneven flanges.
OffsetThe shape of the strip in which the web of the strip is not aligned with the cavity and looks similar to the letter “C”.
Offset PivotA pin-and-socket hardware device with bearing contact by means of which a door is suspended in its frame, allowing it to swing about an axis which is normally located about %” out from the door face.
OITCAn acronym that stands for Outdoor/Indoor Transmission Class, which is the standard used for indicating the rate of transmission of sound between outdoor and indoor spaces in a structure.
OleoresinousA compound consisting of natural and synthetic resins mixed with drying oils.
One-step DistributorA term for a company that buys products directly from a manufacturer and then sells them directly to the end user. As opposed to two step distribution.
OpaquePreventing light from traveling through and therefore not transparent or translucent.
Open UnitA unit, complete in its entirety, with the exception of glass, glazing materials or screens, which is shipped in an assembled condition and later glazed according to the instructions of the manufacturer.
Open-Air Arena TestA blast test conducted in an open field with explosives. Multiple specimens may be included in such a test at various distances and orientations from the detonation source.
OpeningA breach or aperture in a wall or roof surface intended to accept a fenestration product or that is left open.
Open-Stud FramingA building framing system comprised of unsheathed structural components (studs, headers, sills, plates, etc.) and areas of sheer wall framing.
Operable DoorA door that is intended to be opened and closed.
Operable WindowAny window that is able to open and close.
Operating ForceThe force required to initiate or maintain a sash, leaf, or panel motion in either the opening or closing direction.
Operational HardwareComponents of an egress system that require manipulation or operation by an occupant to effect egress. For the purpose of this standard, “locks” or “latches” are defined as devices intended to prohibit the opening of the window from the exterior.
OperatorThe hardware piece that is most likely crank-operated device for opening and closing casement or jalousie windows.
OptionTerm used in construction documents to indicate that contractor may use one of several products at his or her choice.
OrganicDesignating or composed of any chemical compound containing carbon; derived from living organisms.
Organic CoatingOrganic coatings including paints, enamels and resins. A wide range of colors is achieved through the addition of pigments.
Organic GinishesOrganic coatings including paints, enamels, and resins. A wide range of colors is achieved through the addition of pigments. For further detailed information concerning organic coatings on aluminum, contact the American Architectural Manufacturers Association.
Orial Double Hunga double-hung window where the top sash is larger at 2/3 size and bottom sash is smaller at 1/3 size. In contrast to Cottage Double Hung with an upper sash at 1/3 size and bottom sash 2/3 size.
OrielA bay window type that extrudes or extends from a building, usually from an upper floor, that is supported by corbels or brackets.
OrientationPlacement of windows in regard to access, view, sun, shade, etc.
OSHAOccupational Safety and Health Administration
Outdoor-Indoor Transmission Class (Oitc)A single-number rating calculated in accordance with ASTM E1322, using values of outdoor-indoor transmission loss. It provides an estimate of the sound insulation performance of a facade or building elements. The frequency range used is typical of outdoor traffic noises.
Outside StopAlso called a blind stop, it is the piece of wood trim that is attached to the side jambs on the exterior. See blind stop.
OutswingWindows or doors that swing out.
Overall DimensionsThe external height and width of the product, expressed in millimeters or inches.
Overall Heigh AllowancesThis allowance relates to the AAMA Certification Program, under which window and door manufacturers are permitted to use, without a Waiver of Retest, pile weatherstrips whose nominal height is from +0.5mm (+0.020 in) to -0.3mm (-0.010 in) difference than those used in the test window or door.
Overall HeightThe total thickness of the weatherstrip excluding appurtenances protruding above the pile.
Overhead Closera.) Surface type – An exposed door swing control and closer device mounted on the surface of a door and frame at its head; b.) Semi-concealed type – A door swing control and closing device mortised into the door top rail and/or frame head; and c.) Concealed type – A door swing control and closer device enclosed within the door top rail and/or frame head.
Owner’S RepresentativeA party designated by the owner to act on his behalf.
OX / XOUsed to diagram windows and doors. The “X” indicates the operating panel while the “O” indicates the stationary panel.



P&PPolicies and Procedures
PAPascal (unit of pressure)
Pan Flashing (A.K.A. Sill Pan)A type of flashing used at the base of a rough opening to divert water to the exterior or to the exterior surface of a concealed WRB. Pan flashings have upturned legs at the rear interior edge (back dam) and right and left sides (end dams), to form a three­sided pan that has the front open for drainage. They are intended to collect and drain water toward the exterior, including water that may enter through the window unit or around the window (between the rough opening and the fenestration). Pan flashing can be made from self-adhered flashing or from rigid or semi-rigid material, such as metal or a semi-rigid polymer.
Pan/PanningCosmetic covering, usually found on the exterior of the window or door to achieve aesthetic sight lines or to integrate the window or door system into the building surface or weatherproofing system. If panning is being used for weatherability, the panning is not considered cosmetic, but rather part of the window system.
PaneOne of the compartments of a door or window consisting of a single sheet of glass in a frame; also, a sheet of glass.
PanelA major component of a sliding glass door, consisting of a light of glass in a frame installed within the main (or outer) frame of the door. A panel may be sliding or fixed.
Panel SupportA sub-support between the panel and the building frame which is usually continuous and acts to transfer loads back to the structure. Not to be confused with a panel stiffener, which typically acts to limit deflection of the flat area of the panel.
Panic Device CaseSee CRASH BAR HOUSING.
Panic Exit HardwareA door locking mechanism designed to be always operable from the interior by pressure on a crash bar or lever.
PanningIn replacement window work, the outside aluminum trim that can extend around the perimeter of the window opening; used to cover up the old window material. Panning can be installed in the opening before the window, or can be attached directly to the window before installation.
Parallel Opening WindowA of an sash that moves in direction perpendicular to the plane of the frame for the purpose of ventilation. The sash remains parallel to the frame throughout its range of motion.
Parallel-Schiebe-KippGerman: Parallel tilt and slide unit. See Tilt Slide
ParameterA variable characteristic attribute of an object.
Parametric ObjectAn intelligent object that is part of a single building database, represented in any number of views.
Partial Window ReplacementThe installation of a replacement window where some component of the previously installed window frame will remain in the wall.
Particle Dispersed GlazingGlazing in which the orientation of small particles between two sheets of glass is controlled electrically, thus changing its optical properties.
Parting StopA narrow strip, either integral or applied, that holds a sash or panel in position in a frame.
Passive DoorOne or more hinged leaves or sliding door panels that are normally held inactive by latching or locking hardware, but can become active on the release of the latching or locking hardware.
Passive Haus A German standard for energy use. Heat demand requirement of the Passive House Standard is 4.75 kilo BTUs per square foot per year. Passive House is the gold standard for high performance construction today.
Passive House WindowsSuper insulated and tightly built windows that meet the rigorous and voluntary energy efficiency standards set by the passive house concept that originated in Germany. To be certified Passive Haus in Germany, windows need to meet a European U value of 0.08 (USA converted U value = 0.1409) for the complete window unit.
Passive SolarRefers to the use of the sun’s energy for the heating and cooling of living spaces. In this approach, the building itself or some element of it takes advantage of natural energy characteristics in materials and air created by exposure to the sun. In passive solar building design, windows, walls, and floors are made to collect, store, and distribute solar energy in the form of heat in the winter and reject solar heat in the summer.
Passive Solar Heat GainSolar heat that passes through a material and is captured naturally, not by mechanical means.
PassivehausThe term passive house (Passivhaus in German) refers to a rigorous, voluntary standard for energy efficiency in a building, reducing its ecological footprint. It results in ultra-low energy buildings that require little energy for space heating or cooling.
Patio CoverA one story structure not exceeding 3657 mm (12 ft) in height. Enclosure walls shall be permitted to be of any configuration, provided the open or glazed area of the longer wall and one additional wall is equal to at least 65 percent of the area below a minimum of 2032 mm (6 ft. 8 in) of each wall, measured from the floor.
Patio DoorsTraditionally a large glass sliding door leading to a patio. North American style patio doors are usually simple two panel sliders.
Patio EnclosureA sunroom installed over an exterior surface such as a deck or patio slab.
Patterned GlassA type of glass used to control light, obscure visual detail for privacy, or to provide decorative effects.
Patterned GlassRolled glass having a distinct pattern on one or both surfaces.
Peak Blast Pressure (PiThe maximum value of the pressure over ambient pressure with units of kPa (psi).
Peak DemandThe maximum instantaneous power demand experienced at a particular point in time. The peak cooling demand is the heaviest cooling load seen by the air handlers; the peak heating load is the highest instantaneous heating load seen by the heating system.
Peak LoadThe maximum thermal load to be provided by a heating or cooling system in a house.
PEC ModelProject execution and coordination models. PEC models are project-specific fenestration BIM models that are provided at pre-defined milestones in the project execution process for insertion into the overall project BIM model.
PerformanceDefined in the dictionary as the action or process of carrying out or accomplishing an action, task, or function. Exactly what is needed for the many window and door openings we have in our home.
Performance BondAn insurance document purchased by the contractor which guarantees that the work will be performed in accordance with the Contract Documents.
Performance ClassOne of the five performance classes (R, LC, CW, AW, and SK) within the classification system that provides for several levels of performance. NOTE: This allows the purchaser or specifier to select the appropriate level of performance depending on climatic conditions, height of installation, type of building, etc.
Performance ConditionLevel of protection provided by a fenestration system.
Performance Grade (PG)A rating given by the North American Fenestration Standard (NAFS). A numeric designator that defines a specific set of NAFS-specified product performance requirements for a specific Design Pressure (DP) range as required by conditions at the intended location of the building.
Perimeter Fire ContainmentThe ability of a system of individual components assembled in a specific manner to contain and restrict the migration of flame and hot gases from the floor of origin to the floor(s) above at the building perimeters. These components are: 1) a floor with an hourly fire endurance rating; 2) an exterior curtain wall with or without a hourly fire endurance rating, and 3) the fill material installed between the floor and the curtain wall.
Permanent DeformationA change in shape or dimension that does not disappear when pressures are no longer applied.
Permanent SetThe amount of deflection left in a member after the application and release of a load.
PermeabilityThe time rate of water vapor or gas transmission through a unit area of the material of unit thickness induced by unit vapor pressure difference between two specific surfaces under specified temperature and humidity conditions.
PermeanceThe time rate of water vapor or gas transmission through a unit area of a body, normal to specific parallel surfaces, under specific temperature and humidity conditions.
PermitA document issued by a local, state, county, or federal governmental authority having jurisdiction to authorize specific work on a building.
PhotochromicGlazing with the optical properties that change in response to the amount of incident light.
PhotovoltaicsPhotovoltaics (PV) are solid-state, semiconductor type devices that produce electricity when exposed to light. Electrons in the photovoltaic material are knocked free by light to flow out of the device as an electric current. The more intense the sunlight, the stronger the electric current.
Physical InterlockThe provision in the design of the thermal break cavity which involves the incursion of metal lugs into the cavity area. These lugs prevent the pulling apart of the aluminum components from the thermal break material should a loss of adhesion occur.
Picture SliderA horizontal sliding window with one or two moving sash located on one or both sides of a fixed panel to make up a two or three panel window.
Picture WindowA large, fixed window framed so that it is usually, but not always, longer horizontally than vertically to provide a panoramic view.
Pile WeatherstripUpright cut threads or filaments interlaced, woven, or otherwise joined to a backing.
PineAn evergreen coniferous tree that has clusters of long needle-shaped leaves. Many kinds are grown for their soft timber, which is widely used for furniture and pulp.
PitchThe perceived tone of a sound based upon its representative frequency
PivotAn axis or hardware about which a window, sash, panel, or leaf rotates.
Pivot Bar Or Pivot PinComponents that link the sash to the friction shoe/clutch of the balance.
Pivot WindowA window with a sash that swings open or shut by revolving on pivots at either side of the sash or at top and bottom.
Plank Support SpanThe distance between plank support, including standard joist spacing and other support configurations such as angled joists.
Plank SystemDeck planks and the accessories that mate the planks to sub-decking or other deck components. Plank systems include planks, fasteners, installation clips or clip systems.
Plank Walking Surface AreaThe area of the plank that is exposed after assembly and provides the uppermost surface.
PlanksThe uppermost deck components that together comprise the walking surface.
Plastic FilmA thin plastic film, sometimes used as the inner layers in a triple- or quadruple-glazed window. Used to greatly reduce the weight of true triple or quad glass.
Plastic FilmA thin, plastic substrate sometimes used as the inner layers in a triple- or quadruple- glazed window.
Plastic GlazingPlastic infill materials (including, but not limited to, acrylic, co-polyester, fiberglass-reinforced plastic, and polycarbonate) that are glazed or set in a frame or sash.
PlasticsArtificial substances made of organic polymers that can be extruded or molded into various shapes including window frames and sashes.
Plate GlassThick fine-quality glass, typically used for doors and store windows and originally cast in plates. It has been replaced by float glass.
Plate GlassFlat glass with surfaces that are essentially plane and parallel; it is formed by a rolling process, ground, and polished on both sides. It is available in thicknesses varying from 3.2 mm to 31.8 mm (1/8 in to 1-1/4 in), but has been replaced by float glass.
Plinth BlockThe rectangular slab or block that forms the lowest part of the base of a column, statue, pedestal, or pier. Also called plinth course. Considered the lowest part of the wall of a building that appears above ground level and defines the base of door casing.
PlumbA term that means that something is straight up and down. Is perpendicular to the ground. To make vertical.
Pocket (Channel)A three-sided, U-shaped opening in a sash or frame to receive glazing infill. Contrasted to a rabbet, which is a two-sided, L-shaped section, as with face glazed window sash.
Pocket (Channel) DepthThe inside dimension from the bottom of the pocket to the top. Pocket depth equals the bite plus the edge clearance.
Pocket (Channel) WidthThe measurement between stationary stops (or stationary stop and removable stop) in a U-shaped channel.
Pocket DoorA door panel that slides into an cavity in the wall.
PointsThin, flat, triangular or diamond shaped pieces of zinc used to hold glass into wood sash by driving them into the wood.
PolarizationThe condition of electromagnetic waves in which the transverse motion or field of the wave is confined to a plane or ellipse.
PolybuteneA light-colored liquid, straight-chain aliphatic hydrocarbon polymer that is non­drying and widely used as a major component in sealing and caulking compounds. It is essentially non-reactive and inert.
PolycarbonateA synthetic thermoplastic resin, a linear polymer of carbonic acid, used for molded products, films, and nonbreakable windows.
Polyester ResinAny of a group of thermosetting synthetic resins which are poly-condensation products of dicarboxylic acid and dihydroxy alcohol.
PolyethyleneA straight chain plastic polymer of ethylene.
Polyethylene (Pe) BlendThermoplastics based on polymers made with ethylene as essentially the sole monomer. This shall also be permitted to include PE thermoplastics from pre- and post-consumer recycled thermoplastic materials.
Polyisobutylene (Pib)Synthetic rubber manufactured from isobutylene.
PolymerA high molecular weight chemical structure consisting of a long chain of small molecular units.
PolymerizedTreated by heating or cooking so that molecules of different substances unite into larger molecules of a different substance with individual characteristics.
PolyolA polymer or copolymer terminated with one or more hydroxyl groups (OH).
Polyol ComponentOne of the two components of a thermal break system. Normally in this application, it is a fully compounded blend of polyether polyols with small amounts of catalyst and additives present.
Polypropylene (Pp)Polymer prepared by polymerization of propylene as essentially the sole monomer.
Polystyrene (Ps)Polymer prepared by polymerization of styrene as essentially the sole monomer.
PolysulfideLong-chain aliphatic polymers containing disulfide linkages. They can be converted to rubbers at room temperature upon addition of a curing agent.
Polysulfide BaseSealants made from polysulfide synthetic rubber.
Polysulfide SealantPolysulfide liquid polymer sealant which are mercaptan terminated, long chain aliphatic polymers containing disulfide linkages. They can be converted to rubbers at room temperature without shrinkage upon addition of a curing agent.
PolyurethaneProduct produced by the reaction of a polyfunctional isocyanate with a polyol or other reactant containing two or more hydroxyl groups.
Polyurethane SealantAn organic compound formed by the reaction of a glycol with an isocyanate.
Polyvinyl ButylMaterial used in laminated safety glass and auto glass. Causes shattered glass to be held in place. Referred as PVB.
Polyvinyl ChlorideA common extruded product used in replacement window fabrication and as an exterior cladding on wood windows. Referred to as PVC.
Porch EnclosureA sunroom installed as part of a porch.
PorosityThe presence of numerous visible pits or pin holes at or near the substrate surface.
Positive PressurePressure acting in the inward direction.
Pot LifeThe time interval following the addition of an accelerator or curing agent, before a chemically curing material will become too viscous to apply satisfactorily. Also called work life.
Pour SpeedThe speed at which the material flows from the nozzle into the cavity and the part being filled moves under the nozzle.
Poured And DebridgedFraming system thermal break made by flowing a catalyzed liquid material with low thermal conductivity into a one-piece channel and then removing the base of the channel or bridge after solidification to form a thermally improved extrusion.
PPMParts Per Million (also PPM)
Pre-Cast Window Sill (A.K.A. Window Sill)A product used at the sill of a window masonry opening designed with a slope for the purpose of draining water away from the window masonry opening to the exterior of the building.
PrefinishedFor windows and doors, pre-finished products is a highly sought after option for the quality and completeness of the finish. Creates a furniture grade finish. Refers to a unit that is applied with paint or stain in a factory setting.
Pre-hangerGenerally a company that purchases door components for final assembly.
PreloadA positive and negative wind load (a reduced design pressure) that is applied to a fenestration product or wall assembly to condition the system before running an air leakage, water penetration or structural test.
Preshimmed Tape SealantA sealant having a preformed shape containing solids or discrete particles that limit its deformation under compression.
PressureDifferential force per unit area between the interior and exterior surfaces of the test specimen.
Pressure Build Or Foaming PressureA value for maximum pressure developed under specified conditions as determined by the test method described in AAMA 812-04.
Pressure CoefficientA coefficient which is a function of the building shape, a particular location on the building, the direction of the wind and other factors. The pressure on any part of the building is determined by multiplying the velocity pressure by the appropriate pressure coefficient. Pressure coefficients may be positive or negative. What the BLWT test does essentially is determine the maximum pressure coefficients at numerous locations on the building which the designers will need to determine the design wind loads the wall will be subjected to under extreme wind conditions.
Pressure Differential (AP)The difference between the absolute air pressure on the external surface of a window and the absolute air pressure on the internal surface of the same window. The difference is positive when the external pressure is higher than the internal pressure. When the external pressure is lower than the internal pressure, the difference is negative. This pressure differential is expressed in Pascals (Pa).
Pressure EqualizationThe use of ventilation to achieve a balance in pressure between the drainage and ventilation cavity, and the exterior.
Pressure Equalized Rain Screen Wall System (Prwc)A wall system that functions to control air leakage and water penetration within the cavity through use of an exterior rain screen, a compartmented drainage and ventilation cavity, and an air and water barrier.
Pressure TapA hole, approximately 1 mm in diameter, drilled perpendicularly through the exterior surface of the model wall, into which a metal tube is inserted from the interior surface. The metal tube provides attachment for a plastic tube which leads to the instantaneous pressure measuring device. A sufficient number of pressure taps must be used to adequately define the pressure distribution on the entire wall and on any special exterior architectural feature or geometry.
Primary Active PanelThe main operating panel in a pair of bi-hinge doors.
Primary DoorThat door in a dual-door system so designated by the manufacturer, capable of protecting the building’s interior from climactic elements (as opposed to a secondary door used mainly for performance enhancement).
Primary SealThe seal beyond which no water is allowed to pass. It is the location within the wall construction that is ultimately responsible for maintaining water impermeability between the interior and exterior of a building envelope.
Primary SealantA sealant applied to the inner shoulders of a spacer with its principle purpose to minimize moisture, gas and solvent migration into the unit’s air space.
Primary WindowThat window in a dual window unit so designated by the manufacturer, capable of protecting the building’s interior from climatic elements (as opposed to a secondary window used mainly for performance enhancement).
PrimeUndercoat is a preparatory coating put on materials before painting. Priming ensures better adhesion of paint to the surface, increases paint durability, and provides additional protection for the material being painted.
Prime DoorA swinging exterior passage door capable of protecting the building’s interior from climatic elements. A prime door does not require a storm door to perform as intended, but storm doors may be applied as additional protection from climatic elements.
Prime Window (Primary Window)The first window completely installed in a rough opening, which is designed to function as the sole fenestration product (contrasted to a storm window, which serves as a secondary window in conjunction with a primary window).
Primed WindowA window or door unit that already has a coat of primer applied and is ready to be painted on site.
PrimerA coating specifically designed to enhance the adhesion of sealant systems to certain surfaces, or to form a barrier to prevent migration of components, or to seal a porous substrate.
PrimingSealing of a porous surface so that a compound will not stain, lose elasticity shrink excessively, etc., because of loss of oil or vehicle into the surround. A sealant primer or surface conditioner may be used to promote adhesion of a curing-type sealant to certain surfaces.
Produced XustainablyIs the creation of goods and services using processes and systems that are: Non-polluting. Conserving of energy and natural resources. Economically viable. Safe and healthful for workers, communities, and consumers.
Product DesignationsSkylights included in this document are identified by the product designation code, which includes product type, performance class, performance grade and size tested.
Product LineA given series of fenestration products typically defined by operator type, frame type and a set of basic frame profiles.
Product TypeEach product type and class requires testing the largest size (maximum glazed area) for which compliance is desired for entry into the performance class.
Production Unit Testing ProcedurePerformance testing of a randomly selected production unit, conducted in accordance with the requirements of the certification program.
Production UnitsPrimary windows and sliding glass doors which are intended for installation in manufactured housing.
ProfileReferring to the cross-sectional geometry or property of a frame, sash, or its components.
ProjectDimensionally-accurate project-specific fenestration BIM models, provided at pre­defined milestones in the project execution process, for insertion into the project
Project in WindowsWindow that tilt, swing or tilt toward the interior.
Project ManualThe 8 2″x 11″ paper size bound book of written documents prepared by the Architect for a Project, including the bidding requirements, Conditions of the Contact and technical Specifications, used by the Contractor in bidding & building the project.
Projected WindowA window fitted with one or more sashes opening on pivoted arms or hinges that project away from the wall. Refers to casements, awnings, and hoppers.
Projected WindowProjected windows have one or more sash hinged or pivoted at the top or bottom which project inward or outward from the plane of the window with or without fixed lites of glass.
ProponentThe entity that orders the test. This may be a window or component manufacturer, an installer, contractor or builder.
Propylene CarbonateSolvent used for cleaning and flushing thermal break compounds from the nozzles and operating parts of the mixing and filling machine.
PrototypeA unit built strictly for testing purposes.
Prototype UnitsA unit built strictly for test purposes.
ProvideThe construction term “provide” means “to furnish and install, complete and ready for the intended use.”
PSFPounds per Square Foot
PSIPounds per Square Inch
Pull HardwareA fixed handle or grip used to pull a door open.
Pull StileA vertical member applied to the side of the glass and used to operate the sash.
Pulsating PressureA pressure in which pressure difference across the specimen is rapidly transitioned from one level of differential air pressure to another and back within a prescribed time period.
PultrusionA continuous process of manufacturing of composite materials with constant cross-section whereby reinforcing fiber, typically polyester polymers, are pulled through a resin.
Punched OpeningA discrete elevation of curtain wall, storefront or sloped glazing that is surrounded in its entirety by another building wall system such a masonry, EIFS, panels or similarly cladding systems.
Punched OpeningsGenerally, the construction term for conventional windows.
PurlinA horizontal beam along the length of a roof, resting on a main rafter and supporting the common rafters or boards
Push HardwareA fixed bar or plate used to push a door open.
Push-out CasementA casement window opened by pushing out the window.
PVCSee Polyvinyl chloride
Pyrolytic CoatingA low-e, thin-film coating applied at high temperature. See also HARD COATING.
Pyrolytic Low-EA low- E coating which typically uses tin oxide with some additives deposited directly onto a glass surface while it is still hot. The result is a baked-on surface layer that is hard and durable and thus sometimes referred to as a “hard coat.” Pyrolytic coatings are typically used in insulated glass units with the low-E surface inside the sealed air space, but can also be applied to single-pane glass and separate storm windows.



Quarter RoundA window unit one quarter of a circle in shape.



RabbetA groove, channel or recess in a piece of wood that is typically joined to the matching piece of wood.
RackingMovement and distortion of sash or frames so that the corners no longer form their original angles.
Radiant HeatHeat energy transmitted by electromagnetic waves in contrast to heat transmitted by conduction or convection.
RadiationThe transfer of heat in the form of electromagnetic waves from one separate surface to another. Energy from the sun reaches the earth by radiation, and a person’s body can lose heat to a cold window or skylight surface in a similar way. Low-E glass reduces the transfer of heat from radiation.
RadiationEnergy released in the form of waves or particles, due to a change in temperature within a gas or vacuum.
RadiusThe measurement from the center of a circle to the outside edge.
RafterFor sloped glazing, a main nominally vertical framing member.
RailHorizontal member of a window or door.
Rain ScreenAn exterior wall construction technique consisting of an exterior cladding (outer leaf), a cavity, and an inner leaf. Rain screens are subdivided into two distinct performance categories, one being pressure equalized rain screen and the second being drained and back ventilated (D&BV).
ReactionA mutual action of chemical agents upon each other, resulting in a chemical change.
ReceptorA device installed in a rough opening that is designed to receive the window.
ReclaimThe action or process of reclaiming or being reclaimed or reused.
RecycleTo make something new from something that has been used before.
Recycled AluminumIs the process by which scrap aluminium can be reused in products after its initial production. The process involves simply re-melting the metal, which is far less expensive and energy-intensive than creating new aluminium
Recycled ContentRefers to the portion of materials used in a product that have been diverted from the solid waste stream.
Reference Velocity PressureThe pressure equal to the product of the square of the reference velocity, a factor of one-half and the air density.
ReflectanceThe ratio of reflected radiant energy to incident radiant energy.
ReflectionThe process by which incident flux leaves a surface or medium from the incident side, without change in frequency.
Reflective Coated GlassGlass with metallic or metallic oxide coatings applied onto or into the glass surface to provide reduction of solar radiant energy, conductive heat energy and visible light transmission.
Reflective GlassWindow glass coated to reflect radiation striking the surface of the glass.
ReflectivityThe reflectance of a microscopically homogeneous sample with a clean, optically smooth surface and of thickness sufficient to be completely opaque.
RefractionThe phenomenon of light or other waves being deflected from a straight path when it passes at an oblique angle from one medium (such as air) to another (such as glass).
Regulation The term “Regulations” includes laws, ordinances, statutes, and lawful orders issued by authorities having jurisdiction, as well as rules, conventions, and agreements within the construction industry that control performance of the Work.
Reinforced MullionA connecting member that goes between two windows, two doors, or between an adjacent window and door that is reinforced with a material such as steel or aluminum.
Reinforced ThermoplasticsCompound in which a thermoplastic is blended with or chemically coupled to reinforcing additives, such as fibers, spheres or other materials.
ReinforcementThe material added to individual sash, leaf, panel, or frame members to increase strength and/or stiffness.
Reinforcing MullionA horizontal or vertical member with an added continuous mullion stiffener and joining two or more individual fenestration units along the sides of the mullion stiffener.
Relative Heat GainAn energy comparison factor for glass products combining the radiant and conductive heat gas in under specific conditions, (200 BTUs times the shading coefficient + 14 degrees times the summer U-value).
Relative HumidityThe percentage of moisture in the air in relationship to the amount of moisture the air could hold at that given temperature. At 100 percent relative humidity, moisture condenses and falls as rain.
Relative PressureThe dimensionless ratio of a sound’s pressure to a standardized reference sound pressure.
Releasing AgentA petroleum-based agent, usually spray applied to a wall or fixture, that will not permit cementitious material to adhere to the wall or fixture.
Relief KerfA kerf that is cut or machined into a frame member that helps prevent warping.
RemodelTo replace or improve a building or its parts.
RemodelTo replace or improve a building or its components
Removable Double GlazingThe use of a second sash or pane of glass as a storm panel to provide an air space between the glass of the window and the storm panel.
Removable Interior GrilleGrilles that are fastened to the inside of the window with latches, pins or snaps that can be removed for cleaning.
Removable MullionA mullion separating door openings, designed to permit its temporary removal.
Removable Multiple Glazing Panel (Rmgp)A glazed panel that can be installed in a sash, leaf, or panel on either the interior side or exterior side of the primary glazing.
RepairThe term “repair” means to fix and restore a portion or portions of the building to a sound, acceptable state of operation and serviceability or appearance.  Repairs will be expected to last approximately as long as a replacement.
ReplaceThe term “replace” means to remove an existing element or elements from the building and install a new element of like kind or a  salvaged element acceptable to the Owner and Architect, completely and properly anchored to the substrate and surrounding materials; also the term can mean to provide a substitute or replacement for an item.
Replaceable WeathersealA seal which can be readily removed from a retaining groove of an assembled and installed fenestration product and not an integral part of a framing member or applied with adhesives.
Replacement InstallationInstallation of a fenestration product that is designed for replacement of existing like and type, by either destructive or nondestructive installation methods.
Replacement WindowsA window that is installed in an existing window opening after removal of all or part of a previously installed window. The generic replacement window is a vinyl fabricated window replaced inside the frame of the original window, hence often referred to as “slide-in” or “pocket window”.
ResetThe term “Reset” means to remove an existing element or elements from the building and reinstall it completely and properly anchored to the substrate and surrounding materials.
RESFENA computer program used to calculate energy use and associated costs based on window selection in residential buildings.
Residential BuildingAny building used or intended primarily for a single or multiple family dwelling.
Residential Building – Group As Defined In The Iecc)Residential occupancies containing more than two dwelling units where the occupants are primarily permanent in nature such as apartment houses, boarding houses (not transient), convents, monasteries, rectories, fraternities and sororities, dormitories and rooming houses. For the purpose of this code, reference to Group R- 2 occupancies shall refer to buildings that are three stories or less in height above grade.
Residential Building – Group R-4 (As Defined In The Iecc)Residential occupancies shall include buildings arranged for occupancies as Residential Care/Assisted Living Facilities including more than five but not more than 16 occupants, excluding staff. For the purpose of this code, reference to Group R-4 occupancies shall refer to buildings which are three stories or less in height above grade.
Residential Translucent Sloped Glazing SystemA translucent glazed roof structure over a conditioned or un-conditioned space having a minimum glazed area of 15 square feet.
Resilient TapeA pre-shaped, rubbery sealing material furnished in varying thicknesses and widths, in roll form. May be plain or reinforced with scrim, twine, rubber or other materials.
Resin Chemical FamilyShall refer to the base chemistry of the resin backbone. Examples (not exclusionary) include: Polyester, Vinyl Ester and Urethane.
Resin ComponentA synonym for polyol component.
Responsible ContractorThe party contractually responsible for that portion of the work.
RetrofitTo add new materials or equipment not provided at the time of original construction.
Retrofit WindowA replacement window designed to be installed over a pre-existing window frame.
RetrofittingAdding or replacing items on existing buildings. Typical retrofit products are replacement doors and windows, insulation, storm windows, caulking, weatherstripping, vents, landscaping.
ReuseUse again or more than once.
RevealThat part of the edge of a door or window frame/jamb not covered by the casing.
Reverse Cottage WindowA type of double-hung window in which the lower sash is smaller than the upper sash. See Orial Double Hung.
Revolving DoorAn exterior door consisting of two or more leaves that pivot about a common vertical axis within a cylindrically shaped vestibule.
Revolving Door CanopyThat circular part of a revolving door between the ceiling sheet and the roof sheet. Any canopy that has a flat side and is not a complete circle is referred to as a clipped canopy.
Rework MaterialPrincipally material from a manufacturer’s facility or another facility of known compatible composition that has been reground, pelletized or pulverized after having been previously processed by extrusion.
Rigid (Static) ModelThis is a building model of rigid construction which remains undeflected and stationary when placed in the flowing air of the BLWT. It is the type of model used to establish wind load or curtain walls. Pressure taps distributed over the surfaces of this type of model are used to obtain pressure distributions.
Rim TypeWhich is mounted on the surface of a door, usually by screws from the reverse side. It is mounted independently of the lock and engages with the lock mechanism by means of a tail piece or metal extension.
Roll ScreenAn insect screen that rolls up or to the side for storage.
Roll shuttersA rolling component or sectional overhead door consisting of many horizontal slats.
RolladenA German roll shutter used for shading, security, privacy and storm protection.
Roller AssemblyConsists of roller(s), roller axle(s), any roller tire(s), any roller assembly housing(s), any height adjustment mechanism, and where used as an integral part of the roller assembly, sill rail of the sliding glass door operating panel.
Roller LatchA hardware device for holding a door in closed position. It consists of a spring-loaded roller mortised into the edge of a door so as to engage with a grooved strike mortised into the frame jamb.
Roller StrikeSee STRIKE.
Roll-form AluminumA thin sheet of aluminum used to clad the exterior of wood windows. Much thinner than windows clad with extruded aluminum.
RoofThe cover of a building; includes the roofing system. Assembly of interacting components designed to weatherproof, and sometimes to insulate the roof surface of a building.
Roof WindowA fixed or operable window similar to a skylight placed in the sloping surface of a roof.
Roof, SunroomThe cover over a sunroom structure. Sunroom roofs shall be made of solid panel materials, glazed surfaces, screening or other materials and assemblies.
Room TemperatureTemperature normally experienced in the average workplace and defined as 24°C ± 5°C (75 °F ± 10°F).
Rough OpeningThe opening in a wall into which a door or window is to be installed.
Rough Opening GapThe space between the rough opening and the window or door frame.
Round TopA semicircle window, usually placed on top of another window or a door. See Circle Top.
R-Pointequal to double that of other anchors, achieved by using two anchors instead of one or by using an anchor that is twice as rigid as those used at other points.
R-valueA measure of the resistance of a glazing material or fenestration assembly to heat flow. It is the inverse of the U-factor (R = 1/U) and is expressed in units of hr-sq ft.-°F/Btu. A high-R-value window has a greater resistance to heat flow and a higher insulating value than one with a low R-value.



Safe Off VoidThe gap or linear void area between the curtain wall system and the structural floor slab.
Safety Glass Annealed glass that is strengthened, toughened or reinforced that is less subject to breakage or splintering. There are two types of safety glass that meet the CPSC-federal standard, 16 CFR 1201, Cat. II: Tempered and Laminated.
Safety GlazingThe use of safety glass and certain plastics in hazardous locations. Building codes require safety glazing in two broad types of hazardous locations. (1) Glazing subject to accidental human impact, such as in doors, sidelights (glazing next to doors), other glazing that extends to or near the floor or walking surface, and glazing in the walls and enclosures of bathing compartments. (2) Skylights or sloped glazing in walls and roofs greater than 15 degrees from the vertical. Laminated glass or certain plastics are required to reduce the possibility of any part of the glazing from vacating the glazed opening when broken.
Safing Impaling ClipA “Z”-shaped, galvanized steel clip used to retain the fire safing materials.
Sag And Flow TestA procedure involving vertical applications of sealants to specified surfaces or shapes under predetermined conditions of temperature and time intervals. The tendency to run or sag is observed and is reported as none, very slight, slight, etc.
SaggingThe inability of a sealant to support its own weight in a joint.
SashA portion of a window that includes the glass, rails and stiles, but does not include the frame into which it is fitted.
Sash BalanceA mechanism comprised of springs, pulleys or counterweights that help a double-hung window remain open.
Sash Balance AdjustmentIf applicable, enables a single balance or combination of balances, to accommodate a range of sash weights. Adjustment details and sash weight range shall be specified by the balance manufacturer.
Sash Balance Rated CapacityThe manufacturer’s specified minimum and maximum weight carrying capacity per balance based on the Balance Rated Travel Range (BRTR). BLRC = Balance(s) Lowest Rated Capacity, BHRC = Balance(s) Highest Rated Capacity
Sash CordThe rope that attaches a double hung sash to the sash balance.
Sash CrackThe total length of prime sash crack between the sash of the operable lights and the main frame and between meeting stiles or rails. The crack length of lights that are not normally operable but are easily removable shall be included when determining total crack length. For fixed windows, the crack length is the perimeter of the main frame measured adjacent to the glass.
Sash LiftA handle attached to or routed into the bottom rail of the lower sash in a single- or double-hung window.
Sash LimiterHardware that controls a window opening amount.
Sash LockHardware attached to the sashes of a double hung window that can fix both in the shut position
Sash OpeningThe clear daylight opening of an open sash.
Sash Operating ModeThe direction and movement of the operable portion of a window assembly. Sash operating modes include, but are not limited to, project-out awning, project-in hopper, outward-projecting casement, horizontal sliding or rolling, vertical sliding or hung, etc.
Sash PullsThe routed handle on the vertical stiles of a sliding window that allow the window to be easily opened.
Sash Travel RangeThe total range of sash travel, during normal operation, from the fully-closed to the fully-opened positions with restraints such as sash stops or any other limiting means in place.
Sash Weight (Wgt)The total weight of the sash including the glazing material, framing members, latches, lock(s) and all other components and attachments.
Sash WeightsThe counterweights of older double-hung windows that kept the sash from closing. Usually found behind the window jamb inside the wall.
Sawtooth RoofA roof composed of a series of single-pitch roofs whose shorter or vertical side has windows for light and air.
SBCCISouthern Building Code Conference International
Scant PlasticA condition along the edge of the laminate where the vinyl interlayer does not extend completely to the edge of the innermost glass component. Measurement is made of the maximum extent of the void from the edge of the innermost glass component.
ScreenWoven mesh of metal, plastic, or fiberglass stretched over a window opening to permit air to pass through, but not insects.
Screen FrameThe frame surrounding a screen.
ScreeningA mesh-like material that can cover a fenestration opening.
Screw-On Bead Or StopA stop, molding or bead fastened by screws.
ScribeTo score or mark along a cutting line.
Seal PlugWeather barrier installed to prevent entry of water, snow, dust, or insects into a rough opening gap.
SealantAny of a variety of compounds used to fill and seal joints or openings in wood, metal, masonry, and other materials, as contrasted to a sealer, which is a liquid used to seal a porous surface. Some common types of sealants are: neoprene, polysulfide rubber, silicone, acrylic latex, butyl rubber, and polyurethane.
Sealant BeadA sealant or compound, such as caulking or glazing bead, etc., applied to a joint regardless of the method of application. Also, a molding or stop used to hold glass or panels in position.
Sealed Insulating Glass UnitsUnits constructed of two or more lites of glass separated and hermetically sealed to spacer frames at the glass edges with the enclosed air changer(s) dehydrated at the plant’s atmospheric pressure.
SealerA liquid used to seal a porous surface. (See Sealant)
Sealing WireAn additional material that is inserted into the head of some polyamide strips and which is heat activated during the curing process of liquid or powder coating.
SEBSingle Entry Bond required by US customs on every shipment with a commercial Value of $2,000 or more.
sebThe surface or surfaces of a wall responsible for preventing water infiltration into the building interior. In Surface Barrier Systems, the exterior-most surface is the weather resistant barrier (WRB). In Membrane/Drainage Systems, the membrane applied behind the exterior surface is the weather resistant barrier (WRB).
Secondary Active PanelThe panel in a set of bi-folding doors that does not have the lockset.
Secondary DoorThat door in a dual-door system so designated by the manufacturer, used on the interior or exterior of, and in tandem with, a primary door designated by the manufacturer to be used for the purpose of performance enhancement. Not to be used by themselves as primary doors.
Secondary LockA secondary lock is any lock that does not allow forced-entry from the exterior by restricting the movement of a sash or vent to less than one-half inch. Any mechanism which allows more than a one-half inch opening shall be classified as a ventilating lock.
Secondary SealantA sealant applied into the exterior glass-spacer cavity to provide elastic, structural bonding of the assembly, in single-sealed units, this sealant also has low gas and moisture vapor transmission property to achieve effective unit performance.
Secondary Storm Product (Ssp)A door, window, or skylight product intended to be used only in conjunction with a primary door, window, or skylight product for the purpose of enhancement of performance in a system with the primary product. A secondary storm product can be attached to the internal or external frame or sash of the primary product. A secondary storm product is also considered a secondary door or window.
Secondary WindowThat window in a dual window unit so designated by the manufacturer, used on the exterior of, or interior of, and in tandem with a primary window for the purpose of performance enhancement. Not to be used by themselves as primary windows.
Sectional DrawingA drawing of a surface revealed by an imaginary plane cut through the project, or portion thereof, in such a manner as to show the composition of the surface as it would appear if the part intervening between the cut plane and the eye of the observer were removed.
Security DoorsA range of measures used to strengthen doors against door breaching, ram-raiding and lock picking, and prevent crimes like burglary and home invasions
Security HardwareHardware providing protection from fire, intruders, and other external agents.
Security ShuttersA rolling heavy gauge shutter used to protect your home and family from exterior forces applied to the windows or doors.
SEERSeasonal Energy Efficiency Ratio
Seismic LoadBuilding movement and forces caused by earthquake motion.
Self-Adhering FlashingsFlexible facing materials coated completely or partially on at least one side with an adhesive material and which do not depend on mechanical fasteners for attachment. They are used to bridge the joint (gap) between fenestration framing members and the adjacent weather resistive barriers or sealed drainage plane material. The purpose of flashing is to drain water away from the fenestration product to the exterior.
Self-Cleaning GlassGlass coated with a layer of titanium dioxide that reacts with sunlight to break down dirt and dust.
Self-Leveling SealantA sealant formulation having a consistency that will permit it to achieve a smooth level surface when applied in a horizontal joint.
SeriesManufacturers shall classify their products in groups called Series. Each series defines significant properties of the product group that relate to its component materials, profile, geometry, and intended application. Changes in component materials such as material durometer (greater than ± 10%), UV stabilizer, or grade of a material that alter the product’s performance or application shall denote a change in series. Changes in the density (greater than ± 15%) of foam filled weather seals shall denote a change in series. Design and construction characteristics such as profile geometry, designed method of compression, or hollow versus solid foam core that alter the product’s performance or application shall also denote a change in series.
ServiceabilityThe capacity of a building product, component, construction or assembly to perform the function(s) for which it was designed and constructed.
ServiceableAccessible without major reconstruction of the widow, door, SSP, TDD, roof window, or unit skylight.
SettingPlacement of lites or panels in sash or frames; and action of a sealant as it becomes more firm after application.
Setting BlockA small piece of neoprene or other suitable material used to position a piece of glass in its frame.
Setting BlockA device or member that supports the weight of the glazing and is in direct contact with an edge of the glazing after final installation.
Setting TimeA term used rather loosely to describe that period when a material has either dried sufficiently through solvent release, or cured sufficiently through chemical reaction, to reach a specified condition.
SGCCSafety Glazing Certification Council
Shade ScreenAlso called a solar shade, solar screen or sun screen, it is a specially manufactured heavy screen that helps reduce glare, block harmful UV rays and improve the energy efficiency of the home.
Shading CoefficientA measure of the ability of a window or skylight to transmit solar heat, relative to that of a 3mm sheet of clear single glass. It is being phased out in favor of the solar heat gain coefficient, and is approximately equal to the SHGC multiplied by 1.15. It is expressed as a number without units between 0 and 1. The lower a window’s solar heat gain coefficient or shading coefficient, the less solar heat it transmits, and the greater is its shading ability. Included is the directly transmitted solar radiation, as well as the solar energy absorbed and then redirected to the indoor space.
Shear PanelA panel used to brace a building wall against racking; in skylights, glass may be used as a shear panel, requiring special design considerations.
Shear StrengthThe maximum shear stress that a material is capable of sustaining. Shear strength is calculated from the maximum load during a shear or torsion test and is based on the original dimensions of the cross section of the specimen. Ability of the thermal barrier material to resist slippage or tearing parallel to the line of application of loading (pure or transverse shear) or perpendicular to the line of load application as in bending (longitudinal shear).
Sheathing TapeA tape manufactured for the purpose of sealing horizontal, vertical, and diagonal joints in the weather resistant barrier (WRB). Appropriate materials for this purpose are those recommended by the weather resistant barrier (WRB) manufacturer for the intended purpose.
Sheet GlassA transparent, flat glass found in older windows, now largely replaced by float glass.
Sheet GlassFlat glass made by continuous drawing and whose surface has a characteristic waviness. Because of the long usage of the term, much thin float glass is still incorrectly referred to as sheet glass.
SHGCSee solar heat gain coefficient
ShimA thin, flat or wedge-shaped piece of suitable material used to level or plumb a window or door frame during installation. Lateral shims are placed at the jambs; setting shims are placed at the sill.
Shock Tube TestA blast test conducted in an enclosure that utilizes compressed air, fuel/air mixtures or explosives to simulate a blast event.
ShockwaveA mass of highly compressed air that radiates out from an explosion source producing an increase in ambient air pressure.
Shoe/ClutchA component of a Type 2 balance which provides an engagement location for the pivot pin or pivot bar. The shoe/clutch is permitted to provide other functions not related to vertical sash counterbalancing and is available in assorted sizes that suit the pocket size of varied frame designs.
Shore “A” HardnessMeasure of firmness of a compound by means of a Durometer Hardness Gauge (A hardness range of 20-25 is about the firmness of an art gum eraser. A hardness of 90 is about the firmness of a rubber heel).
Shore D HardnessProvides a relative ranking of profile surface hardness. Measure of the firmness of a material measured by means of a Durometer Hardness
Shore HardnessMeasure of firmness of a material measured by means of a Durometer Hardness Gauge. (A range of 20-25 is about the firmness of an art gum eraser. 90 is about the firmness of a rubber shoe heel).
Shore HardnessGauge (a range of 20-25 is about the firmness of an art gum eraser; 90 is about the firmness of a rubber shoe heel).
Short-Wave Infrared RadiationInvisible radiation, just beyond red light on the electromagnetic spectrum (between 0.7 and 2.5 microns), emitted by hot surfaces and included in solar radiation.
ShrinkageA permanent loss of overall length due to material construction and/or relaxation from environmental and/or installation factors.
Shrinkage TestA determination of the percentage loss in volume of a sealant when tested in a specified size and shape under controlled conditions of temperature, humidity, and time intervals.
Shrinkage, DryA uniform, end to end contraction of the thermal break material in the extruded cavity after the material has been fully cured. Dry shrinkage is characterized by the absence of thermal break resin on the cavity walls in the “shrink back” area.
Shrinkage, WetThe end to end contraction of the freshly poured thermal barrier material as it gels or sets up within the extruded cavity caused by the center of the pour solidifying quicker than the outer perimeter. Wet shrinkage is characterized by a thin layer of thermal barrier resin on the cavity walls in the “shrink back” area.
Side JambThe vertical side pieces of a window or door frame.
Side LightSee Side Lite
Side LiteAlso referred to as a side light. Usually stationary and with a vertical emphasis that flanks a door where visual emphasis is desired.
Side-Hinged (Inswinging) WindowA window that consists of sash hinged at the jambs and swings inward using exposed butt hinges or concealed butt hinges and in some cases friction hinges. It is primarily for cleaning or escape and rescue purposes, but not for ventilation other than in the case of emergency. The gateway test size is larger than for casement windows, but otherwise the same requirements are met.
Side-Hinged Door SystemA door system having, at a minimum, a hinge attachment of any type between a leaf and jamb, mullion or edge of another leaf but having a single, fixed vertical axis about which the leaf rotates between open and closed positions. These systems include, as a minimum, a single operating leaf, surrounding frame, and components. The surrounding frame has vertical and horizontal members that are joined at the intersection and that fully encompass the operating and/or fixed leaf/leaves. Additional operating and/or fixed leaves, side lites, transoms, framing, and mullions are often included.
sidelightsNnormally fixed units, installed adjacent to a door.
Sight-LineThe line defining the perimeter of the daylight opening of a window. It may be formed by the sash, spacer assembly, or the glazing stop.
Silicone SealantA sealant having as its chemical composition a backbone consisting of alternating silicon-oxygen atoms.
SillThe lowest horizontal member in a door, window, or sash frame.
Sill AngleThe pitch of the exterior window sill. An L-shaped installation accessory that may be employed at the sill of a replacement window to accommodate the slope of the existing sill construction.
Sill HornThe horizontal projection of a wood window sill that forms the base for the brick molding.
Sill NosingA wood member attached to the outside of the sill. This nosing is added to a narrow sill and may help to tie together a single mullion or double mullion unit, etc.
Sill PanAn under window or door flashing for maximum weatherproofing protection. Used to divert water to the exterior.
Sill TrackThe track provided at the sill of a sliding glass door. Also, the sill member incorporating such a track.
Simulated Divided Lites (SDLs)A window meant to look as if it is made up of true divided panes of glass. It is actually made of a single large piece of glass with grilles installed on the inside and outside surfaces of the glass. Meant to closely simulate true divided lites. The better simulated SDL’s have spacer bars inserted inside the glass between the inside and outside grid bars.
Single GlazingOne single thickness of glass in a window or door.
Single MaterialProfiles extruded from a single compound. Weathering and other physical characteristics are uniform throughout the profile.
Single ModeThe primary unit is closed and the outer window/door is opened fully, and the insect screen (when offered or specified by the manufacturer) is in the functional position.
Single-Acting DoorA door mounted to swing in one direction only from the plane of its frame.
Single-Hung WindowA hung style window with two sashes; the top one stationary and the bottom movable.
Single-Sealed UnitsSealed insulating glass units where the structural bonding and moisture sealing is accomplished by a single seal at the edge.
Single-Wtrength Glass. Glass that is 3/32″ thick. Specifically thickness between 0.085″and 0.100″ (2.16–2.54 mm). Opposed to double-strength glass that is 1/8″ thick.
Site-Built SystemA fenestration assembly supplied in an unassembled or partially assembled state consisting of more than one supplier’s fabricated parts, components, locking/latching hardware, and/or accessories for final assembly at the project site. Excluded from this definition are door systems that are shipped from a district manufacturer without locking/latching hardware. NOTE: As no individual distinct manufacturer incurs the sole responsibility for the design, composition, and performance of site-built fenestration assemblies, such assemblies are not addressed by this Standard/Specification.
SkinDoor covering material.
SkylightA roof window that gives light and ventilation.
SlabA door panel without the hardware.
Slag Wool/RockwoolA fibrous insulation board consisting of inorganic steel slag or rock fibers bonded together with thermosetting resins acting as a binder system.
Sliding DoorsA door that opens by sliding instead of swinging
Sliding Glass DoorA door fitted with one or more panels that move horizontally on a track and/or in grooves. Moving action is usually of rolling type (rather than sliding type). Also called gliding door, rolling glass door, and patio sliding door.
Sliding WindowA window fitted with one or more sashes opening by sliding horizontally or vertically in grooves provided by frame members. Vertical sliders may be single- or double-hung.
Sliding WindowsA window that opens by sliding instead of swinging
Sloped GlazingA glass and framing assembly that is sloped more than 15° from vertical and which forms essentially the entire roof of the structure. Generally this is a single slope construction. (Other than unit skylights.)
Sloped Glazing SystemA glass and framing assembly that is sloped more than 15° from vertical and which forms essentially the entire roof of the structure; generally this is a single slope construction.
Sloped Sill AdapterEnclose the cavity between the bottom of the replacement window and the sloped wooden sill of the old window
SloughingA condition wherein scales peel off or become loose, either partially or entirely, from the pultrusion.
SMAScreen Manufacturers Association
Smart WindowGeneric term for windows with switchable coatings to control solar gain.
SmokeThe airborne solid and liquid particulate and gases evolved when a material undergoes pyrolysis or combustion.
Smoke ContainmentThe ability of a system of materials assembled in a specific manner to contain and restrict the migration of smoke from the floor of origin to the floor(s) above.
Smoke SealA seal that exhibits the ability to prevent the passage of smoke and hot gases.
Snap-In Bead Or StopA stop, molding or bead that snaps into position without additional fastening. (See SCREW-ON BEAD OR STOP.)
Snow LoadLoads imposed on a building wall, roof, or skylight by the accumulation of snow; generally a long-term load.
SnubberAn inter-locking alignment component or feature, used at the “hinge side” of a projected or casement sash, to ensure proper seating of weather seals, or for structural integrity. Also known as snug bars, or bevel blocks.
Socially ResponsibleIs the idea that a company should embrace its social responsibilities and not be solely focused on maximizing profits.
Soffit BracketA bracket for mounting an exposed overhead door closer to the underside of a door frame head or transom bar; used for outswinging doors only.
Soft Coating)Generally refers to silver-based, low-e coating. So called due to its susceptibility to damage through abrasion. The coating generally consists of a multilayer structure of alternate dielectric and thin transparent metal layers which are deposited in a vacuum chamber. Also known as sputtered coating.
Soft-Coat GlassA coating used in an insulating glass unit that offers glass low-emissivity and better solar control with a process called sputter coating. Unlike hard-coat glass, soft-coat glass requires special care and handling.
SoftwoodType of lumber from conifer evergreen trees, such as pine, fir, larch, ceder, and redwood.
Solar AbsorptanceFraction or percent of the sun’s radiation that is absorbed by a surface or material; for glass, standard values are normally published for the sun’s rays normal to the surface.
Solar Coefficient Glassis a value that determines one type of thermal performance of a glass unit (panel or window) in a building. Essentially, it is the ratio of solar gain (due to direct sunlight) passing through a glass unit to the solar energy which passes through 3mm Clear FloatGlass.
Solar Control CoatingsThin film coatings on glass or plastic that absorb or reflect solar energy, thereby reducing solar gain.
Solar Control GlassGlass that has a special coating for absorbing and reflecting solar energy.
Solar EnergyThermal radiation from the sun; as measured by short radiation wavelengths, less than three microns long.
Solar Heat Gain Coefficient (SHGC)The fraction of solar radiation admitted through a window or skylight, both directly transmitted, and absorbed and subsequently released inward. The solar heat gain coefficient has replaced the shading coefficient as the standard indicator of a window’s shading ability. It is expressed as a number between 0 and 1. The lower a window’s solar heat gain coefficient, the less solar heat it transmits, and the greater its shading ability. SHGC can be expressed in terms of the glass alone or can refer to the entire window assembly.
Solar RadiationThe total radiant energy from the sun, including ultraviolet and infrared wave lengths as well as visible light.
Solar ReflectanceFraction or percent of the sun’s radiation that is reflected by a surface or material.
Solar Reflecting GlassGlass with a transparent metal or metal oxide coating which reflects a portion of the sun’s radiation.
Solar ScreenA sun shading device, such as screens, panels, louvers, or blinds, installed to intercept solar radiation.
Solar SpectrumThe intensity variation of sunlight across its spectral range.
Solar TransmittanceFraction or percent of sun’s radiation that is transmitted by a transparent or translucent material.
SolariumA sunroom featuring a high percentage of glazed surfaces used as walls and roof systems.
Solid-Core DoorDoors that are solid underneath the door skins, as opposed to a hollow-core doors.
Solids ContentA determination of the non-volatile matter of a compound at a specified temperature and time interval. Usually expressed in percentage by weight and the difference between this figure and 100%, represents the volatile matter or loss by evaporation.
Solids Content TestA determination of the non-volatile matter of a sealant at a specified temperature and time interval, usually expressed as percentage by weight of the solid matter left after evaporation.
Solvent Release SealantA sealant that cures primarily through solvent evaporation.
SoneThe unit of measure of loudness defined as 40 dB at 1000 Hz.
Sound Attenuation GlassGlass fabricated to reduce or control the levels of environmental sound
Sound GlassGlass fabricated to reduce or control the levels of environmental sound
Sound IntensityThe square of the relative pressure of a sound representing the power per unit area of the sound in “watts per square meter” (W/m2).
Sound Power (W)Rate of transmission of a sound’s energy in “Watts” (W).
Sound Pressure Level (SPL)Twenty times (20x) the base ten logarithm of a sound’s relative pressure represented in decibels (dB).
Sound Transmission Class (STC)The sound transmission loss rating of a material over a selected range of sound frequencies. The higher the number, the less sound transmitted.
Sound Transmission CoefficientThe fraction of the airborne sound power incident on the test specimen that is transmitted by the specimen and radiated on the other side.
Sound Transmission Loss (STL)Ten times (10x) the common logarithm of the reciprocal of the sound transmission coefficient. The quantity so obtained is expressed in decibels (dB).
Sound-Insulating GlassGlazing that is fixed on resilient mountings and separated so as to reduce sound transmission. Also known as sound-resistive glass.
SpacerA material, (aluminum, stainless steel, foam or thermal plastic) separating two panes of glass in an insulating glass panel.
Spacer CornersSpecific methods used in joining the spacer lengths into spacer frames including interlocking keys, bending, soldering, or welding.
Spacer DepthThat dimension of the spacer that is measured perpendicular to the glass surface.
Spacer WidthThat dimension of the spacer that is measured perpendicular to the glass surface and establishes the unit’s air space.
SpanThe clear distance measured parallel to the length of a mullion or divider between support points.
SpandrelA portion of an exterior wall between a window on one floor and a window on the floor above.
Spandrel AreaThe area of the spandrel infill between the primary sash or frame members.
Spandrel BeamA beam which lies in the same vertical plane as the exterior wall.
Spandrel GlassUnlike vision glass, which is meant to be transparent,spandrel glass is designed to be opaque in order to help hide features between the floors of a building, including vents, wires, slab ends and mechanical equipment.
Specialty Shape WindowsGenerally referred to as windows with odd or uncommon shapes.
SpecificatonsApart of the Contract Documents contained in the Project Manual consisting of written descriptions of a technical nature of materials, equipment construction systems, standards and workmanship. Under the Uniform System, the Specifications comprise sixteen Divisions.
Spectrally Selective GlazingGlazing that is transparent to some wavelengths of the solar spectrum and reflective to others. Typical spectrally selective coatings are transparent to visible light and reflect short-wave and long-wave infrared as well as UV radiation. Spectrally selectivity can be achieved with low-E coatings and/or high-performance tints.
Spectrally Selective TintA tinted glazing with optical properties that are transparent to some wavelengths of energy and reflective to others. Typical spectrally selective tints are transparent to visible light and reflect short-wave and long-wave infrared radiation.
Speed ControlThe mechanism that controls the rate of speed at which a door will operate.
Spindle (A.K.A Split Spindle)A rigid bar or bars which transfer movement of the handle to the lock mechanism.
Spray CoatingThe process of applying a resinous coating by atomizing it into a spray or mist, and curing it into a continuous film.
Sputtered Low-EA multi-layered low-E coating deposited on glass or plastic film. Typically consists of three primary layers with at least one layer of metal. Sputtered coatings often use one, two or three silver layers and must be protected from humidity and contact. For this reason, they are often referred to as “soft coat.” Sputter coatings are typically used in insulated glass units with the low-E surface inside the sealed air space, but can also be applied to plastic and used in suspended films or retrofit window films.
SquareTwo construction members that meet at a right (90°) angle. In fenestration, the condition in which the jambs are perpendicular to the head and sills.
Square FootThe area of a unit measured in feet.
StackedTwo or more windows arranged vertically.
StaggerTo offset building members or fasteners in a horizontal or vertical plane in alternating sequence.
Stained GlassColored glass used to form decorative or pictorial designs, notably for church windows, both by painting and especially by setting contrasting pieces in a lead framework like a mosaic. When incorporated into windows and doors, the stained glass is placed inside the glass thermal pane and sealed.
StandardAn approved criterion governing the quality of a construction material, operation, functional requirement, or method of assembly.
Standard Test ProfileA specific part selected by the manufacturer that is representative of a single or multiple product series that is to be used in AAMA certified products. The part is representative of a series in component materials, profile geometry, or other characteristics that alter a product’s performance or application.
Static PressureApplication of a fixed pressure difference across the specimen.
StationaryA inoperable panel or sash.
Stationary StopThe permanent stop or lip of a rabbet onto which the lites or panels are set.
STCSound Transmisson Class
STC Reference ContourA curve that is fitted to the measured transmission loss data from 125 Hz to 4000 Hz to determine the Sound Transmission Class of a barrier.
StewardshipThe careful and responsible management of something entrusted to one’s care
Stick GrilleA grille with no exterior frame.
StiffenerA reinforcing member which serves to limit the deflection of the member to which it is attached.
StileThe upright or vertical edges of a door, window, or screen.
Stile and Rail DoorA type of wood door with decorative raised panels surrounded by a frame.
StockStandard size raw building materials or standard equipment.
StoolThe shelf-like board of the interior part of the window sill, against which the bottom rail of the sash closes.
StopThe molding on the inside of a window frame against which the window sash closes; in the case of a double-hung window, the sash slides against the stop. Also called bead, side stop, window stop, and parting stop.
Store FrontThe side of a store facing a street, usually containing display windows.
Store Front SashAn assembly of moulding members forming a continuous frame for a fixed glass store front.
Storm DoorAn additional, non-thermal door placed in front of an exterior door for additional protection for weather elements.
Storm WindowA second window placed either inside our outside of a window to protect against bad weather and to offer increased insulation.
StoryA horizontal division of a building; that portion between one floor and the floor above.
Story DriftSee DRIFT
Story HeightVertical distance between a designated point or component at one floor level and the same designated point or component at adjoining floor levels of a building structure.
Straw Foam SealantAn aerosol foam container from which the polymer is extruded through a simple tube dispenser. A straw-type dispenser is attached to the valve of the container and is controlled by a lever actuator-connector. Normally this devise is intended for limited re-use.
Stress RelaxationStress relaxation is that property which enables a compound to be extended without increasing its internal stress.
StrikeAn opening or retaining device provided in the head, jamb or threshold of a door frame or in the edge of a stile of an inactive door to receive a lock or latch bolt. (Also referred to as a Keeper or Strike Plate). a) Box Strike – A strike consisting of a face plate with rectangular opening and a box-like enclosure attached to the back of the plate and surrounding the opening. b) Dustproof Strike: A strike which is placed in the floor, sill or threshold of an opening, to receive a flush bolt, and is equipped with a spring-loaded follower to cover the recess and prevent its filling with dirt. c) Electric Strike: A strike used with a latch lock and designed to be actuated by a remotely controlled electro-magnet, to permit the door to be opened without retracting the latch. d) Roller Strike: A strike for latch bolts, having a roller mounted in the tip to reduce friction.
Striking OffThe operation of smoothing excess sealant at the sight line.
Structural GasketA synthetic rubber gasket designed to engage the edge of glass or panel in a surrounding frame by forcing an interlocking filler strip into a grooved recess in the face of the gasket. Such gaskets are structurally capable of transmitting wind and dead loads from the glass or panel to the frame.
Structural GlassFlat glass that is usually colored or opaque and frequently ground and polished, used for structural purposes. Also, glass block, usually hollow, that is used for structural purposes.
Structural GlazingGlazing which is part of the structural design of the facade of a building.
Structural Glazing GasketsCured elastomeric channel-shaped extrusions used in place of a conventional sash to install glass products onto structurally supporting sub-frames with the pressure of sealing exerted by the insert of separate lock strip wedging splines.
Structural IntegrityA structure’s uncompromised ability to safely resist the required loads.
Structural MullionsAlso called “mullion stiffeners,” must independently or in conjunction with Common or Combination Mullions be designed to withstand full design load requirements of the project specifications. Evidence of compliance shall be either by testing for mathematical calculation.
Structural Silicone GlazingA system in which the glass product is bonded to the framing members of a curtain wall utilizing a structural silicone adhesive / sealant without the presence of outdoor retainers or stops.
Structural Test Pressure (Stp)The overload pressure differential applied to a window, door system, TDD, roof window, SSP. or unit skylight. (Not to be confused with design pressure (DP) or Performance Grade (PG)).
StuccoCementitious mixture used for exterior plaster.
Styrene CopolymersThose polymers incorporating styrene and at least one other functional group in the repeating unit through co-polymerization of the base monomers.
Sub-Assembly UnitA unit, complete in its entirety, including the glazing of windows or other glazing panels into their respective fixed or moving sash frames, which is shipped with such glazing panels separate from each other or from any master frame. This master frame may either be disassembled or assembled. The connection of the master frame to the glazed, fixed, or moving panels shall take place later according to the instructions of the manufacturer utilizing all of the components supplied by the manufacturer.
SubcontractorA person or organization who has a direct Contract with a prime Contractor to perform a portion of the Work at the site.
Sub-FrameA framework built fastened and sealed into a window or door opening in a concrete or masonry wall, to which the window or door frame is secured.
SubsillA separate framing member that, when installed on the underside of a sill, becomes an integral part of the sill.
Substantial CompletionThe term “Substantial Completion” means the date on which the Architect issues a Certificate of Substantial Completion based on an inspection of the Work, by which it can be determined that the Work is sufficiently complete in accordance with the Contract Documents so that the Owner can occupy or utilize the Work for the use for which it is intended.  A Certificate of Substantial Completion may be issued for each individual building as it is completed, if this is in the Owner’s best interests.
SubstrateInner layer of a co-extrusion.
SubstructureThat part of a building structure below the ground.
Summer ModeWhen the primary window/door is closed and latched, the secondary window/door or outer primary window/door is opened fully and insect screen (when offered or specified by the manufacturer) is in the functional position.
Sun Control FilmA tinted or reflective film applied to the glazing surface to reduce visible, ultra-violet, or total transmission of solar radiation. Reduces solar heat gain in summer and glare. Some can be removed and reapplied with changing seasons.
Sun ScreenA screen consisting of a heavy mesh to filter or block direct sun and solar heat gain.
SunlightThe portion of solar energy which is detectable by the human eye; it accounts for about 44 percent of the total radiation wavelength spectrum.
SunroomA one-story structure attached to a dwelling with a glazing area in excess of 40 percent of the gross area of the structure’s exterior walls and roof.
SunspaceA sunroom.
Super WindowA window with a very low U-factor, typically less than 0.15, achieved through the use of multiple glazing, low-E coatings, and gas fills.
SuperstructureThat part of a building structure above the foundation or ground level.
SupplierA person or organization who supplies materials or equipment for the Work, including that fabricated to a special design, but who does not perform labor at the site.
Surface Barrier Wall SystemsSystems in which the outermost surface of the wall or roof is the sole barrier to intrusion of liquid water.
Surface BoltA rod or bolt mounted on the face of a door to lock it to the frame and/or sill. It is operated manually.
Surface CoatingThe deposition of a thin-film coating on a surface.
Surface Coefficient (H)The ratio of steady-state heat exchange between the surface and its external surroundings to the temperature difference between the surface and its surroundings. It is expressed in terms of time rate of heat flow per unit area of a particular surface by the combined effects of radiation, conduction and convection for a unit temperature difference between the surface and the air. Subscripts I and II are used to denote indoor and outdoor air spaces, respectively.
Surface ConductanceThe time rate of heat flow between a unit area of a surface and its surrounding environment resulting from radiation, conduction, and convection, induced by a unit temperature difference between the surface and the environment (sometimes called surface or air film coefficient). Subscripts are used to differentiate between the room-side temperature difference between the test specimen surfaces
Surplus PlasticExcess vinyl interlayer extending beyond the glass edges of the laminate. Interlayer should be trimmed flush when required depth of silicone joint exceeds design thickness of outboard ply.
SurroundThe accent trim around a window or door.
Suspended FilmPolymer-based, optically clear glazing layer mounted between glass layers in a multiple-glazed system.
Suspended Film Insulating Glass UnitI.G. unit manufactured with a light and energy controlling film suspended within the air space.
Suspended GlazingGlazing system suspended from above. This innovation, first achieved in projects of the 1960s, made possible continuous glass facades, without mullions.
SustainabilityThe quality of not being harmful to the environment or depleting natural resources, and thereby supporting long-termecological balance.
SustainableThe ability to be maintained at a certain rate or level.
Sustainable Business PracticeA process by which companies manage their financial, social and environmental risks, obligations and opportunities. Often defined as managing the triple bottom line: profits, people and planet
Sustainable DesignAlso called environmental design, environmentally sustainable design, environmentally conscious design, etc., is the philosophy of designing physical objects and services to comply with the principles of social, economic, and ecological sustainability.
Sustainable EconomicsIs the ability of an economy to support a defined level of economic production indefinitely.
Sustainable ForestA forest that is carefully managed so that as trees are felled they are replaced with seedlings that eventually grow into mature trees.
Sustainable StandardsVoluntary, usually third party-assessed, norms and standards relating to environmental, social, ethical and food safety
SweepThe bottom vinyl piece on a door that offers a tight seal when the door is closed by making contact with the threshold.
Sweep Strip Or Door SweepA weatherstrip mounted at the top or bottom edge of a swing door.
SWISteel Window Institute
SwingThe direction of opening of a swing door. (Same as Hand of Door).
Swing Of WingsThe arc of travel of the wings of a revolving door beyond the enclosure walls.
Swinging Exterior PassageA swinging exterior passage door installed in an exterior wall. A passage door which is side hinged and operates by swinging inward or outward.
Switchable GlazingGlazing with optical properties that can be reversibly switched from clear to dark or reflective.
Switchable GlazingsGlazings with optical properties that can be reversibly switched from clear to dark or reflective with the application of an external stimulus, e.g.: heat, light, electric signal, etc. Also known as DYNAMIC GLAZING. See also GASOCHROMIC GLAZING.
Sympathetic ResonanceThe phenomenon whereby materials of similar characteristics (mass, stiffness, etc.) respond to incident sound frequencies in a similar manner thereby aiding in the transmission of the sound. The use of dissimilar materials can reduce the transmission of sound.
SystemThe parts, components, hardware, and/or accessories that yield a complete, fully functional assembly.



Tape SealantA sealant having a pre-formed shape, and intended to be used in a joint under compression.
Telescoping Patio DoorsSimilar to a multi-panel lift/slide, a telescoping door door consists of several — three or more — panels that slide past each other. 
Temperate Northern ClimateIn weather testing, a North American metropolitan area testing site located within 73 to 100°W longitude and 37 to 50°N latitude.
Tempered GlassTreated glass that is strengthened by reheating it to just below the melting point and then suddenly cooling it. When shattered, it breaks into small pieces. Approximately five times stronger than standard annealed glass; is required as safety glazing in patio doors, entrance doors, side lights, and other hazardous locations. It cannot be recut after tempering.
Template (For Hardware)A master pattern or scaled drawing showing all dimensions and hole spacing for hardware application.
TenonA rectangular extension that is cut in a piece of wood to be joined with a piece of wood with a coordinating mortise.
Tensile StrengthThe greatest longitudinal stress a substance can bear before rupturing.
Terne (metal)An alloy of lead and tin applied to steel by dipping steel into molten terne metal. The alloy has a dull appearance resulting from the high lead content.
Test Pressure DifferenceDifference between the external pressure and the internal pressure across a closed and locked test specimen expressed as Pascals (lbf/ft2). It is called positive pressure when the external pressure of windows and doors is higher than the internal pressure and is called negative pressure when the external pressure is lower than the internal pressure.
Test SpecimenA complete, fully functioning window, door, SSP, TDD, roof window, or unit skylight supplied by the applicant and fitted in the test apparatus in accordance with the manufacturer’s written installation instructions (including manufacturer’s instructions for clearance, shimming and anchoring).
Test WeightThe amount of weight that is attached to the guide block when performing test procedure from Sections 8.2 and 8.3 of AAMA 902-07. Test weight equals the balance’s rated capacity without regard to built-in friction of the window unit. Test weight will equal Balance(s) Lowest Rated Capacity (BLRC) when performing the test procedure from Section 8.2. Test weight will equal Balance(s) Highest Rated Capacity (BHRC) when performing the test procedure from Section 8.3.
Testing LaboratoriesA “testing laboratory” is an independent entity engaged to perform specific inspections or tests, either at the Project Site or elsewhere, and to report on and, if required, to interpret results of those inspections or tests.
Thermal BarrierThe insertion of a non-heat-conducting material between two (2) conductive members, thus avoiding heat transfer.
Thermal BreakAn element of low thermal conductivity placed in an assembly to reduce or prevent the flow of thermal energy between conductive materials.
Thermal BridgeA thermally conducive area of an exterior enclosure which will allow heat to transfer from the interior of the building to the exterior at a greater rate then the other parts of the enclosure.
Thermal ConductivityAbility of a material to allow the flow of heat from its warmer surface through the material to its colder surface.
Thermal ConductivityThe time rate of heat flow per unit area under steady-state conditions from the air on the warm side of a body to the air on the cold side, per unit temperature difference between the warm and cold air.
Thermal CyclingThe repeated heating and cooling of a specimen from a stated low temperature to a stated high temperature and back again.
Thermal Diffusivit YThermal conductivity per unit of heat capacity.
Thermal EmissivitySimilar to thermal emittance, except that the suffix “-ivity” refers to a property of general material, while “-ance” refers to a specific material with a certain thickness, surface finish, etc.
Thermal EmittanceThe ability of a surface to emit long-wave radiation relative to that of a perfect black body. Also known as the long-wave infrared emittance. A perfect black body has an emittance equal to 1.0, while a perfect reflector has an emittance equal to zero.
Thermal ExpansionChange in dimension of a material as a result of temperature change.
Thermal IsolationPhysical and space conditioning separation from conditioned space(s) consisting of existing or new walls, doors and/or windows. The conditioned space(s) shall be controlled as separate zones for heating and cooling or conditioned by separate equipment
Thermal MassMass in a building (furnishings or structure) that is used to absorb solar gain during the day and release the heat as the space cools in the evening.
Thermal MovementThermal movement is the expansion or contraction of the curtain wall elements due to the rise and fall of their temperature.
Thermal RadiationThe heat transfer by radiation from surfaces at or near the room temperature (i.e.: wavelengths in the range 2.5-50 microns). It is often referred to as far IR radiation or long-wave IR radiation.
Thermal ResistanceA property of a substance or construction which retards the flow of heat; one measure of this property is R-value.
Thermal Short CircuitThe by-passing of the low conductivity of the thermal break material by a highly conductive material such as aluminum or a steel fastener. If the aluminum bridge were not removed or debridged from the cavity it would become a thermal short circuit.
Thermal StressStress in glass caused by temperature differences either between the central area of the glass and the edges or between the surfaces and the thickness center; the latter is often referred to as “thermal shock.”
Thermal Transmittance (U-Factor) A.K.A. U- ValueA measure of the total heat transfer through a fenestration system including boundary air films, due to conduction, convection and radiation under specific environmental conditions expressed in W/(m2-°C) [Btu/(ft2-h-°F)]. The lower the U- factor, the less heat will be transferred through the fenestration system. For fenestration systems, the overall U-factor is dependent on the area-weighted U- factors contributed by the center-of-glass, the edge-of-glass and the frame.
Thermally BrokenIt is manufacturing the aluminum frame window with a barrier in between the inside and outside window frames that will prevent the conductive thermal energy loss.
ThermochromicsGlazing with optical properties that can change in response to temperature changes.
ThermogramAn image of an object taken with an infrared camera that shows surface temperature variations.
ThermoplasticA polymer material that turns to liquid when heated and becomes solid when cooled and is able to repeat these processes.
Thin StileSee STILE.
ThresholdThe member that lies at the bottom of a sliding glass door or swinging door; the sill of a doorway.
Threshold Limit ValueThe concentration that should not be exceeded during any part of the working exposure.
Threshold Limit Value (1)Time Weighted Average (TLV-TWA) The time weighted average concentration for a normal 8-hour workday and a 40-hour workweek, to which nearly all workers may be repeatedly exposed, day after day, without adverse effect.
Threshold Limit Value (2)Short Term Exposure Limit (TLV-STEL) – The concentration to which workers can be exposed continuously for a short period of time without suffering from 1) irritation, 2) chronic or irreversible tissue damage, or 3) narcosis of sufficient degree to increase the likelihood of accidental injury, impair self-rescue or materially reduce work efficiency, and provided that the TLV-TWA is not exceeded. It is not a separate independent exposure limit, rather it supplements the time-weighted average (TWA) limit where there are recognized acute effects from a substance whose toxic effects are primarily of a chronic nature.
Through-Wall FlashingFlashing that extends completely underneath the sill or over the head of a window, and has an upturned leg on the interior side.
Through-Wall PenetrationAny opening in an exterior wall of a building that penetrates the water protecting surface(s) of the wall.
ThrowThe distance which a lock bolt or latch bolt projects when in locked position.
ThumbturnA permanently attached small lever which, when turned, operates the bolt on a lock in the same manner as a key.
Tight Grasping, Pinching Or Twisting MotionThe application of forces that require more than 22.2 N (5 lbf) to be exerted by the fingers, hands, wrists, arms, or other body parts(s). Furthermore, the rotational movement of the wrist, shoulder, or other body part(s) should not exceed 95 degrees. Grasping is the act of wrapping one’s hand around an object, such that the opposing finger(s) and thumb contact one another.
Tilt Lift Slide DoorsDoors that tilt to the interior for secure ventilation and also lift at the bottom rail to slide to the side.
Tilt Slide DoorA sliding door that may tilt in a locked and secure position and slide to the side. Easily described as a sliding door similar to the sliding door of a mini van. Windows may also be made in this function. Used in places of large windows or doors that have no corresponding floor space for a swing function. Unlike traditional sliding windows or doors, these units have superior air infiltration ratings.
Tilt Turn DoorsAlso referred to as tilt and turn doors. Refers to the dual action unit such that it tilts while still locked and secured on bottom hinges and turns like a regular door. These doors are used for patio door and side entry doors. Not used for front entry doors.
Tilt turn windowsAlso referred to as tilt and turn windows, and means the window is a dual action window such that the sash tilts slightly toward the inside and turns like a casement swing window. Used in all aspects of windows with minor configuration for multi-story safety limits; tilt first; turn first; egress compatible; turn only; tilt only.
Tilt WindowA single- or double-hung window whose operable sash can be tilted into the room for interior washability. Also half the operation in a dual action window such as a tilt/turn unit.
Tilt WindowsWindows that tilt as a single open operation, primarily towards the inside.
Tinted GlassGlass colored by incorporation of a mineral admixture. Any tinting reduces both visual and radiant transmittance.
Tinted GlassBody colored glass of specific batch ingredient formulation to produce light reducing and / or heat absorbing glass products.
Toe BeadSealant applied at the base of the channel, prior to setting the lite or panel, to prevent leakage.
ToolingThe operation of pressing in and striking sealant in a joint; to press the sealant against the sides of a joint and secure good adhesion; the finishing off of the surface of a sealant in a joint so that it is flush with the surface.
Top-Hinged WindowA window consisting of sash hinged at the head which swings inward or outward using a continuous top hinge or individual hinges, primarily for cleaning or emergency escape and rescue purposes and not for ventilation.
Top-hung ScreenAn insect screen for patio doors that have top rollers or guides.
TorsionThe twist induced in a product by the application of a static load to an extreme free corner of that product and normal to its plane.
Torsional StrengthThe ability of the thermal break material to resist twisting or rotation as a result of a torsional load such as that resulting from thermal stresses, handling, fabrication or uneven glazing pressure.
Total AreaThis area is the area of the entire fenestration system being considered, vision area or spandrel area plus frame area.
Total Design DisplacementThe design earthquake lateral displacement, including additional displacement due to actual and accidental torsion.
Total Glass ThicknessThe sum of the thicknesses of all layers of glass in the window, not including the thickness of any glazing cavities.
Total Glass ThicknessThe sum of thicknesses of all layers of glass in the window, not including the thickness of any glazing cavities.
Total Heat Gain – Summer/Daytime(BTU per hour, per square foot) The sum of the radiant energy and the conductive energy transmitted into the building. (Shading coefficient times ASHRAE solar heat gain factors + summer U-value times the indoor / outdoor temperature differences.)
Total Heat Gain – Summer/Nighttime(BTU per hour, per square foot) The conductive energy transmitted into the building. (Summer U-value times the indoor / outdoor temperature difference.)
Total Heat Loss – Winter/Daytime(BTU per hour, per square foot) The resultant of the radiant energy transmitted into the building and the conductive energy transmitted out of the building. (Shading coefficient times ASHRAE solar heat gain factors + the winter U-value times the outdoor / indoor temperature difference.)
Total Heat Loss – Winter/Nighttime(BTU per hour, per square foot) The conductive energy transmitted to the outdoors. (Winter U-value times the outdoor / indoor temperature difference.)
Total Maximum DisplacementThe maximum considered earthquake lateral displacement, including additional displacement due to actual and accidental torsion.
Total Vertical MovementVertical movement of one floor slab of a structure relative to adjacent floor slabs.
Total Window ProductComplete window unit including the frame, any dividers, and the edge of glass, divider edge, and center of glass areas.
TranslucentA material that permits the passage of light.
TransmittanceThe percentage of radiation that can pass through glazing. Transmittance can be defined for different types of light or energy, e.g., visible light transmittance, UV transmittance, or total solar energy transmittance.
Transmittance (Vt) A.K.A. Visible Light Transmittance (Vlt)VT. The VT is dimensionless and is expressed as a decimal less than 1.0. The lower the value for VT the less visible light is transmitted into the building.
TransomA window stacked above another window or door, to allow extra light or ventilation into a location.
Transom BarThe horizontal frame member which separates the door opening from the transom.
Transom BracketA bracket used to support an all-glass transom over an all-glass door when the latter has no metal top rail and no transom bar is used.
Transom WindowThe window sash located above a door. Also called transom light.
TransparentA material that permits the passage of light with minimal distortion or scattering, so that the bodies lying on the opposite side from the viewer may be clearly seen.
Trapezoid Windowsa four-sided shaped window that has two sides that are parallel and two sides that are not parallel.
T-RatingBy definition it is a measure of the time it takes for any thermocouple on the unexposed side (the side of the assembly away from the fire) to reach a temperature 325°F above the temperature of this thermocouple prior to the start of the test. Thus it is a measure of thermal conductivity.
Tributary WidthThe width of wind-bearing area contributing to the load on a mullion or divider.
TrimDecorative covering framing the interior of the fenestration product after it’s installed.
Trim HardwareDecorative finish hardware used to operate functional hardware or the door itself.
Trimmer StudSee Jack Stud.
Triple GlazingThree panes of glass or plastic with two air spaces between.
Triple Hung WindowTriple hung windows are vertically operating windows in which the sash weight is offset by a counterbalancing mechanism mounted in the window. One or more locking devices are furnished to secure the sash in the closed position. Three sash in a triple hung window are operable.
Triple SliderA three sash slider, with the center sash being stationary and the two flanker sashes movable sideways.
Tropical Awning WindowA window consisting of one or more top-hinged or pivoted sash which swings outward at the bottom edge, operated by one control device securely closing them at both jambs without the use of any additional manually controlled locking devices.
True Divided Lites (TDL)Before glass was made in large sheets, windows were made by joining small panes with wood strips. Therefore, a window or door with true muntin grids are separating smaller pieces of glass.
True MuntinsA profile member used horizontally or vertically to divide a vision area into individual smaller lites of glass.
Tubular Daylighting Device (TDD)A non-operable device primarily designed to transmit daylight from a roof surface to an interior ceiling surface via a tubular conduit. The device consists of an exterior glazed weathering surface, a light transmitting tube with a reflective inside surface and an interior sealing device, such as a translucent ceiling panel. See also Hybrid Tubular Daylighting Device.
TürenGerman for Doors
Turn-Tilt Window UnitSee DUAL-ACTION WINDOW
Two-Part (Multi­Component) SealantA product comprised of a base and curing agent or accelerator, necessarily packaged in two separate containers which are uniformly mixed just prior to use.
Two-step DistributorA term for a company that buys products directly from a manufacturer, and then sells them to a retail store, which then sells to retail consumers. As opposed to one step distribution.
Type 1 Friction Based Sash BalanceA mechanical device comprised of a lifting force source and an attached friction shoe/clutch, which, when mounted in a window unit, contributes to proper sash operation and maintaining sash position at any point along the full range of travel.
Type 2 Friction Based Sash BalanceA mechanical devise comprised of a lifting force source and a friction mechanism integral to the balance. The balance, when mounted in a window unit, contributes to proper sash operation and maintaining sash position at any point along the full range of travel.
Type A ProductsProducts that pass this specification without use of a primer. (See Annex 3 in AAMA 711) CAUTION: Type A products may require a primer under certain field conditions. The type classification only relates to passing this specification. Consult the flashing manufacturer for installation conditions and details.
Type B ProductsProducts that require a primer to pass any part of this specification. (See Annex 3 in AAMA 711)
TypicalMeans that the item referred to is repeated several times in similar circumstances and locations.



UBCAn acronym for the Uniform Building Code, published by the International Council of Building Officials until 1997, which promoted safety in construction. It was replaced in 2000 by the new International Building Code (IBC), published by the International Code Council (ICC)
U-FactorIndicates the rate heat flows through a product for each degree of temperature difference between one side and the other. U-Factor is the inverse of R-Value. The lower the U-Factor the greater a window’s resistance to heat flow and the better its insulating value.
U-factor (U-value)A measure of the rate of non-solar heat loss or gain through window or door assembly. It is expressed in units of Btu/hr-sq ft-°F (US) or W/sq m-°K (European metric). Values are normally given for NFRC/ASHRAE winter conditions of 0° F (18° C) outdoor temperature, 70° F (21° C) indoor temperature, 15 mph wind, and no solar load. The U-factor may be expressed for the glass alone or the entire window, which includes the effect of the frame and the spacer materials. The lower the U-factor, the greater a window’s resistance to heat flow and the better its insulating value.  To convert the U-factor from US (imperial/IP) to European (metric/SI), multiply the imperial number by 5.678. For example, If U=0.35 Btu/hr-sq ft-°F in imperial units, then 0.35*5.678 = 1.9873. The U-factor in metric units will be 1.9873 W/sq m-°K.
ULUnderwriters Laboratories
UltravioletThe invisible rays of the light spectrum which are below the visible range consisting of radiation below 400 nanometers.
Ultraviolet ExposureThe exposure of the thermal break material to light in the ultraviolet range of the spectrum primarily from direct or reflected sunlight.
Ultraviolet Light (UV)The invisible form of radiation which is not visible to the human eye. It’s in an invisible part of the “electromagnetic spectrum”. Ultraviolet rays are found in everyday sunlight and can cause fading of paint finishes, carpets, and fabrics.
UnconditionedInterior or exterior space with no temperature control system.
Uniform BeadSealant applied to a joint, with uniform width and appearance.
UnitRefers to a complete window, door, or skylight assembly, including frame, sash (or door slab), and glass.
UnitRefers to complete or total assembly, such as for fenestration products including all frame, sash, glazing, door slabs, hardware or other elements defining the complete fenestration product.
Unit DimensionThe measurement of a window or door unit, including the frame. Does not including brickmould.
Unit SkylightA complete factory assembled glass- or plastic-glazed fenestration unit consisting of not more than one panel of glass or plastic installed in a sloped or horizontal orientation primarily for natural daylighting. Unit skylights are either fixed (non- operable) or venting (operable).
United InchA term coined by the window industry. A unit of measurement of window frames, treating the combined width and height in inches as a single measure of length.
Unobstructed Glass OpeningThe visible glass in a window unit.
UpstandThe vertical portion of a panning, flashing, or subsill system that prevents the migration of collected water behind the membrane or into the wall cavity. Collected water is drained to the building exterior.
UrethaneElastomeric material formed by the reaction of a polyol and organic isocyanate. Also called polyurethane.
Urethane SealantUrethane sealant is best recommended for indoor use such as in kitchens, restaurants or warehouse floors where industrial spills are more likely to occur. The fact that it protects against heavy foot traffic also makes it ideal for these areas.
USGBCAn acronym for the U.S. Green Building Council. A non-profit organization most widely recognized for LEED as a certification program for buildings, homes and communities that guides the design, construction, operations and maintenance.
USGSUnited States Geological Survey, which studies and defines earthquake hazards from seismological and geological perspectives, and which produces extensive seismic hazard maps for the United States.
UV GlassSee Low-e glass
UV RadiationRadiation in the invisible spectrum at shorter wave lengths than visible light; generally reference is to the UV portion of the sun’s radiation.
U-valueRate of heat flow through a building (difference between the indoor and outdoor air temperature), a building part (as a wall or window), or a given thickness of a material (as insulation) with lower numbers indicating better insulating properties.
U-Value of Window (Uw)The overall heat transmission in unit time through unit area of the total window product and its boundary air films, induced by unit temperature difference between the environments on each side. The U-value, multiplied by the difference between the indoor and outdoor temperatures and the total window area, yields the total heat transfer through the window resulting from conduction, convection, and radiation.



Vapor BarrierMaterial used in the house envelope to retard the passage of water vapor or moisture.
Vapor RetarderA material that reduces the diffusion of water vapor across a building assembly.
Vehicular-Access DoorA door that is used for vehicular traffic at entrances of buildings such as garages, loading docks, parking lots, factories, and industrial plants, and that is not generally used for pedestrian traffic.
VeneerA layer of natural material applied to the surface of the composite by means of an adhesive.
VentThe movable framework or sash in a glazed window that is hinged or pivoted to swing open.
Vent LimiterHardware that restricts the amount a window is able to open.
VentilationVentilation is the process of supplying and removing air by natural or mechanical means to and from any space. Such air may or may not be conditioned. Proper ventilation improves indoor air quality by allowing air changes within the indoor environment.
Ventilators, IntegratedIntegrated fenestration ventilators are devices independent from, but installed into a fenestration product for the purpose of providing supplemental air ventilation through the fenestration product. Various configurations are available; commonly these systems consist of an exterior (canopy) component covering an opening fabricated through the fenestration product, coupled with an interior component that may adjust to vary the amount of air that flows through the device.
VentingProviding circulation of air or ventilation between two walls or partitions by the use of tubes, breather vents or openings.
Venting UnitA window unit or door that is able to open.
Vertical FenestrationFenestration products that are installed at an angle less than 15 degrees from vertical.
Vertical Sliding WindowA hung or non-hung window consisting or at least one manually operated sash that slides vertically within a common frame.
Vertically Pivoted WindowSee PIVOTED WINDOW
VIVinyl Institute
VinylPolyvinyl chloride material, which can be both rigid or flexible, used for window and door frames.
Vinyl Chloride CopolymerA compound based on a polymer prepared by the co-polymerization of vinyl chloride and other monomers: the vinyl chloride content being at least 80% mass.
Vinyl GlazingA system for holding glass in place with extruded vinyl channel or roll-in shapes.
Vinyl WindowsType of window where the frame and sash are created out of vinyl.
Vinyl-clad WindowWindows in which the exterior wooden parts are covered or capped in vinyl.
ViscoelasticThe property of material that possesses both viscous and elastic behavior. For acoustical applications, a viscoelastic system will dissipate some of acoustical energy in the form of heat.
ViscosityResistance of a fluid to uniformly continuous flow with out turbulence, inertia, or other forces. The degree to which the thermal break material resists fluid flow under a given applied load and at a given temperature.
VisibleA measure of the fraction of visible light that a fenestration system allows into the building. The default and most commonly used reference is the normal incidence
Visible LightThe portion of the electromagnetic spectrum that produces light that can be seen. Wavelengths range from 380 to 720 nanometers.
Visible Light TransmissionThe fraction of the visible portion of the solar spectrum that is transmitted through the glazing (VLTg) or window (VLTw).
Visible Transmittance (VT)A rating of the NFRC that indicates the percentage or fraction of the visible spectrum (380 to 720 nanometers) of light that can come into a room through a window. VT will always be a number between 0 and 1, with a higher number meaning more natural light is coming through.
Vision AreaThe area of the vision infill between the primary sash or frame members.
Voluntary StandardA standard established by a private sector association, organization or technical society, and available for public use.



Waiver of LienAn instrument by which a person or organization who has or may have a right of mechanic’s lien against the property of another relinquishes such right. Waivers of linen are provided to the owner by the general contractor and his sub-contractors & suppliers, at the time a pay request is submitted.
Walking Beam PivotA form of retractable to center-hung pivot.
WallOne of the sides of a room or building connecting floor and ceiling of foundation and roof.
Wall PostThe end components of the enclosure walls of a revolving door.
Warm EdgeTerm used to describe technology that uses insulating spacers to achieve better thermal performance of an insulating glass unit, particularly evident in the increase of edge surface temperatures on the indoor side in the winter.
Warm-Edge TechnologyThe use of low-conductance spacers to reduce heat transfer near the edge of insulated glazing.
Water DammingWater retained by an upright surface.
Water LeakageThe penetration of water that would continuously or repeatedly wet parts of a building or components not designed to be wetted.
Water PenetrationPenetration of water beyond the plane intersecting the innermost projection of the test specimen, not including interior trim and hardware, under the specified conditions of air pressure difference across the specimen.
Water Penetration ResistanceA measurement of the resistance of a fenestration product to the passage of water.
Water Penetration Resistance Test PressureThe pressure differential applied across a test specimen to determine the water penetration resistance rating.
Water Spray VolumeAmount of water sprayed onto the test specimen.
WaterproofingA procedure to make a material impervious to water or dampness, designed to resist a head of water (water pressure).  Any of the material used to waterproof
Water-Resistive Barrier (Wrb)The surface(s) of a wall system which complies with ICC AC 38 and is responsible for preventing water infiltration to the building interior. A membrane, which can be a house wrap or building paper, whose primary function is to act as a drainage plane for liquid water, which has a permeance low enough to keep liquid water from penetrating through the surface.
WavelengthThe distance between two consecutive points of maximum pressure in a sound pulse. Represented as “l” or “lambda”.
WDMAAn acronym for the Window and Door Manufacturers Association. It is a trade organization that defines standards for the window, door and skylight industry.
Weather Resistant Barrier (Wrb)The surface or surfaces of a wall responsible for preventing air and water infiltration to the building interior.
WeatherabilityThe ability of a material to maintain durability under the influence of ultraviolet (UV) light, heat, time and moisture as imposed by laboratory weathering devices
WeatherstrippingA strip of resilient material for covering the joint between the window sash and frame in order to reduce air leaks and prevent water from entering the structure.
Weep HoleA small opening in a wall or window sill member through which water may drain to the building exterior.
Weep ScreedA permanent member with gaps designed to allow liquid water to exit from the membrane drainage plane to the exterior of a building; located at the bottom of wall claddings between the membrane drainage plane and the cladding.
WeepingFailure of a sealant to support its own weight in a horizontal joint, but less pronounced than sagging; the elimination of water or moisture through weep holes in a wall or sash.
WeldAs in vinyl, a way to use heat to fuse two components together.
Wet GlazedGlass that is installed using glazing compounds that seals it to the frame.
Wet GlazingGlazing compounds, e.g., glazing tapes, caulking, and adhesives that are applied to the exterior or interior, or both, that interface between the glass and sash or glazing.
WindloadThe force on a structure arising from the impact of wind on it.
Window Cleaner AnchorAn anchor, either single or double headed, conforming to ASME A39.1 Standard Safety Requirements for Window Cleaning, that will allow a window cleaner to safely access across a window for cleaning. Also known as a Davit.
Window HardwareVarious devices and mechanisms for the window including catches, fasteners and locks, hinges, pivots, lifts and pulls, pulleys and sash weights, sash balances, and stays.
Window Opening Control Device (WOCD) A safety device that keeps a window from opening more than 4 inches, which can be disengaged in emergencies.
Window ReplacementsUse of pocket replacements or slide-in replacements.
Window/Wall AssemblyThe building envelope and the fenestration products incorporated into it.
WindowsAn opening in the wall of a building for the admission of air or light, or both, commonly fitted with a frame in which are set movable sashes containing panes of glass.
Wood Curtain WallDesigned to replicate the crisp, clean aesthetics and narrow site lines of aluminum storefront systems but made of high quality wood post.
Wood DoorsA moving structure used to block off, and allow access to, an entrance to or within an enclosed space, such as a building.
Wood WindowsType of window where the frame and sash are primarily made out of wood.







Zoning OrdinanceThe control by a municipality of the use of land and buildings, the height and bulk of buildings, the density of population, the relation of a lot’s building coverage to open space, the size and location of yards and setbacks, and the provision of any ancillary facilities such as parking. Zoning, established through the adoption of a municipal ordinance, is a principal instrument in implementing a master plan.