Window & Door Vocabulary

A B C D E F G H I J K L M N O P R S T U V W

A

Air Infiltration - The amount of air that passes between a sash and the frame; Measured in terms of cubic feet of air per minute per lineal foot of crack (margin)

Argon Gas - An inert, colorless and odorless gas used to fill the airspace between insulating glass which greatly increases the overall performance of the glass; Argon is less conductive to heat than air

Astragal - A vertical member attached to the meeting edge of one door panel of a pair, bridging the opening and holding one door panel inactive, while the other panel is active; The inactive panel can be unlatched and made operable after the active panel has been opened

Awning Unit - A type of window that swings open at the bottom while being hinged at the top; Unit lets in fresh air while keeping rain out

B

Backband - Additional millwork around the outside edge of the window casing, usually used when the casing consists of flat boards and more detail is desired

Balance - A mechanical device, normally spring loaded, used in hung windows to counterbalance the weight of the sash during opening and closing

Bay Window - A unit comprised of three windows, usually made up of a large center unit and two flanking units at 30- or 45-degree angles to the wall. A bay projects from the wall of the structure

Bead - A molding or stop placed around a window frame to hold the glass in place by pressure

Blind Stop - The frame member on a Double Hung window located between the jamb and the brickmould, the blind stop forms a ridge that supports a storm sash or screen

Bow Window - A combination of units constructed or joined together on the basis of a preset radius

Box Size - AKA Frame Size - Dimensional measurement from outside of frame to outside of frame, excluding the exterior trim/brickmould

Brickmould - A type of external casing which frames windows and doors; Exterior casing around window to cover jambs and provide means for nailing during installation

C

Casement Window - A window unit that swings open from either side

Casing - Molding of various widths, thickness and shapes applied to the framework of window and door units

Check Rail - The bottom rail of the top sash and the top rail of the bottom sash of a Double Hung window that meet horizontally in the center of the unit or the two vertical members of sash in a Slider window that meet in the center

Caulking - Sealants used to seal fixed and movable construction joints and prevent infiltration

Clad - A material (usually aluminum) locked to the outside faces of Window & Door products to provide a durable exterior surface

Cottage-Style - A Double Hung window with a bottom sash that is taller in height that the top sash

D

Daylight Opening - The visible area of glass that is seen; This is slightly smaller than the actual glass size

Design Pressure - Pressure exerted by wind against windows and doors; Required design pressure is the minimum acceptable value specified by the customer

Desiccant - A drying agent used to absorb moisture and/or sealant solvents from within the sealed air space of an insulating glass unit.

Direct Set - A window or door sidelite with no sash; The glass is set directly into the frame and, therefore, is stationary

Double Hung - A window unit that has two operable sashes which move vertically in the frame

Drip Cap - A wood moulding or metal/plastic cap (normally applied to the head) used to direct water away from a unit or door panel, preventing water seepage to the interior

E

Egress Window - A window with specific release hardware and minimum clear opening size to allow occupants to escape through the window in case of a fire

Energy Star - A system for rating the energy performance of specific products ranging from lap top computers to home appliances to windows and doors; The program was established by the Department of Energy and the Environmental Protection Agency

Extension Jamb - Lumber extending from a window or door frame to accommodate different wall thickness

Extruded - The shaping of a metal or vinyl profile by forcing material through a die.

F

Fingerjoint - A series of interlocking fingers precisely cut on the ends of two pieces of wood which mesh together with heat based adhesive

Finger Plough - A groove routed into Double Hung and Slider window sash and used as a handhold for easy operation

Fixed - AKA Stationary; A door panel or window sash installed into a frame which does not operate

Flanker - A unit that is joined to the side of another unit

Flat Casing - Exterior casing with a flat surface

Frame - The horizontal and vertical members of a door or window unit which surround the sash, are used to secure the door or window unit into the rough opening and to the building, and/or to which the hinge and lock strike hardware are normally attached; Frame components are:
Head Jamb - The top horizontal member of the frame
Side Jamb - The vertical side members of the frame
Sill - The bottom horizontal member of the frame

French Casement - A window with two operating sash, both of which are hinged off the side jamb with no center mullion; An astragal and interior mull cap is applied to one sash making it passive/secondary, while the other sash is considered primary

French Door Unit - A frame containing two operating door panels, both of which are hinged off the side jamb with no fixed mullion; The door panel containing the astragal is designed as passive.  The other door panel is designated as active.  The passive panel becomes operable only after the active panel has been opened

G

Gasket - A rubber or plastic pliable material used to separate glazed glass and aluminum or vinyl

Glass Opening - AKA Glazing Area - The open area between the rails and the stile framework of a sash provided for the insertion of glass and / or other glazing options

Glass Size - The measurement of the actual glass, not just the visible glass

Glazing - Glass used for windows or the act of installing glass into a window

Glazing Option - The type and/or configuration of glass to be installed in the glass opening of a sash. Some examples of Glazing options include:

Putty Glazing - Glazing whereby a thin layer of putty or glazing compound is placed on the glass shelf, securing the glass into the sash

Glazing Bead - A small wood or vinyl moulding applied to the perimeter of the glass to secure it within the window or door

Grille - AKA Grids - An ornamental item that visually divides a piece of glass into separate panes
Grilles In Airspace - AKA Grilles Between the Glass - A grid held between two insulating panes of glass, visually dividing the window unit into “separate” panes; Eliminates the need to remove grilles for cleaning

H

Head Board - The board applied to the top of a Bow or Bay window

Hinging - Swing; A term or determination describing the hinge location required to achieve the desired swing direction of a door panel.

Hopper - AKA Ranch Window - An upside down awning window hinged at the bottom and opening inward from the top

I

Inswing Door Unit - Door unit designed and installed to pivot to the interior of a structure

Installation Clip - AKA Masonry Clip - Galvanized steel strips used to fasten windows and/or doors into an opening.

Insulating Glass (IG) - Glazing comprised of two or more glass panes separated by a hermetically sealed airspace; Heat transmission through this type of glass may be as low as half that without such an air space; This space may or may not be filled with an inert gas, such as argon.

Insulation - A material with high resistance (high R-value or low U-value) that is used to retard heat flow. Air, Argon, or Krypton gas spaces between panes of glass provide insulation in IGUs

Interior Casings - AKA Trim - Millwork moulding to finish-off window and door openings, fireplaces, walls and other members

Interlock - A design feature located at the checkrail which enables sash to become engaged with one another when closed.

J

Jamb - The top and side components of a window or door frame

Jambliner - Component which holds the sash into the frame of a Double Hung unit

K

Keeper - A hardware device into which a window locking latch engages for security; The receiving portion of a lock that interlocks with the lock arm; It’s mounted to the upper sash check rail on a double hung or single hung window and the inside surface of the sash stile on a casement window

Krypton - An inert, colorless gas used instead of air in sealed spaces between panes of glass in insulating glass units to increase insulation. Provides greater insulation value than Argon

L

Laminated Glass - Two or more layers of glass bonded together using heat and pressure, with inner layers of transparent plastic; Laminated glass offers one of the best levels of ultraviolet ray blockage over the entire ultraviolet spectrum

Lite - Refers to the glass pane inserted in a door panel or window sash to provide a view, decoration and/or light transmittance

Low E or Low-Emissivity (Lo-E) Glass - A transparent coating applied to a glass surface to separate long wave (heat) energy and short wave (light) energy. The long wave is reflected back to the heat source. The short wave is allowed to pass through the coating; A special type of glass having a transparent material fused into its surface which acts as a thermal mirror; Used to increase a window's insulating value, block or increase heat flow, and reduce fading

M

Masonry Opening - The opening in a brick or stone structure that is intended to receive a window or door unit

Mull - Joining of two units together on a horizontal or vertical plane

Mull Cover/Casing - A casing that covers the joint between two windows or doors when the are mulled side by side or on atop the other

Mullion - AKA Mull Post, Mull Jamb - A stationary member of the frame used to separate window sash, door panels or sidelites; Creates multiple sash units having a continuous head and sill

Muntin Bar - AKA Cutlite Bar - A short, lightweight bar that visually divides a window into “separate” panes

N

Nailing Fin - A vinyl or metal flange integrated into (or attached to) the perimeter of a window frame for installation onto the rough opening’s header, jack studs and rough sill

O

Obscure Glass - AKA Pattern Glass - Glass having a textured surface to make it translucent, but not transparent, which offers more privacy

One Lite - One continuous pane of glass (single or insulating) to fill the glass opening

Operating Unit - A window or door that opens; also referred to as a vent unit or operator

Operator - Crank type hardware for opening a window which swings outward; a jointed metal arm keeps the window open at any position eg: casement and awning windows

Oriel window - A window with unequal sash

OSM - Outside measurement, the outer most part of a sash, screen, etc

Outswing Door Unit - Door unit designed and installed to pivot to the exterior of a structure

Ovolo - An optional style of glazing bead or lite bar; A solid wood moulding that is a combination of a small filet and a quarter round

P

Palladian Window - A large, arch-top window flanked by smaller windows on each side

Pane - A framed sheet of glass

Patio Doors - Sliding glass doors, often used for access to a deck or terrace

Performance Divided Lite - Aluminum bars are adhered to the glass exterior and wood bars to the glass interior; Anodized aluminum spacer bars between the panes simulate the look of true divided panes, while allowing airflow throughout the single insulating glass unit

Picture Window - A large stationary, non-ventilating, window which is designed for a maximum view without obstruction

Prime Latex - A water base primer used to provide a base for a finished top coat

Pyrolytic Coating - A special coating "sprayed" directly onto glass while it is still in a molten state, resulting in a permanently embedded surface coating

R

Radius - A window that incorporates curves, usually full-circle, half-circle, quarter-circle or elliptical shapes

Raised or Flat Panels - A sheet of material inserted into the door in place of glass

R-Value - AKA Thermal Resistance - A measure of resistance to heat flow of a material or construction; A higher value indicates a better heat-insulating property.  The R-Value of an ordinary single-pane sash with a 15 mph wind on one side is about 0.9

Rough Opening (RO) - The structural framework which surrounds the wall opening for the door or window and to which the unit is attached and sealed; Components:
Header - The uppermost horizontal structural member of the rough opening
Cripple (Stud) - The vertical structural members of the rough opening
Sub-Sill - The bottom most horizontal structural member of the rough opening

S

Sash - The portion of a window or door that is separate from the frame and may be either stationary or operating; Uses a single wood/vinyl frame consisting of stiles and rails to be filled with glass; Components:
Rail - The top and bottom horizontal members of the sash or panel assembly
Stiles - The vertical members of a window or door sash

Sash Opening - The frame area that accepts a sash

Sash Set - A unit with glass set into a sash, then set into a frame; A sash set unit may be venting or stationary

Sash Stop - Cover in jamb track that reduces sash travel on hung windows

Screw Boss - A continuous screw track in an extrusion. The track is designed to accept a specific diameter sheet metal screw to provide a secure means of fastening extrusions without the use of reinforcement

Seat Board - A flat board cut to fit the contour of a bow or bay window that’s installed between the sills and the flat wall surface, providing a seat or shelf space

Sidelite - Fixed or operating sash on either or both sides of a door to light an entryway or vestibule.

Sill - The bottom of a door or window frame

Sill Horn - The portion of sill nosing that extends past the side jamb

Sill Nose - Exterior portion of the sill on a window unit

Sill Angle - Extrusion that, when applied below the window, permits the gap below the window to be closed after window installation

Simulated Divided Lite - A method of constructing windows in which muntins are affixed to the inside and outside of a panel of insulating glass to simulate the look of true divided lite

Single Glazed - One thickness of glass, without an airspace

Single Hung - A Double Hung type of window in which the top sash is fixed or inoperable

Slider - A window unit that has two operable sash made to slide horizontally by means of a head and sill track

Specification - Architectural details of a window or door

Square-Out Segment-In - A window or door on which the outside of the sash and frame are square, and the top of the daylight opening on the sash is curved

Stationary - A door panel or window that does not open

STC (Sound Transmission Coefficient) - A higher number rating means better blocking of sound passing through a window

Sticking - The raised, profiled portion of stiles and rails that create the glass shelf

Stile - A vertical sash member; The vertical side pieces of a window sash or door panel

Stool - A horizontal board which may be applied to the interior of the sill in place of the extension jamb for shelf type usage

Stop - A moulding used to hold, position or separate window parts

Strike Plate - A metal piece mortised into or fastened to the face of a door frame to receive the latch or dead bolt when the door is closed

Surround - A frame of wood that encloses the perimeter of a snap-in grille unit, providing greater stability, ease of removal and a professional, finished appearance

Sweep - A rubber or vinyl strip applied to the bottom of a door to create an effective seal against the sill/threshold

T

Tempered Glass - Glass heated to increase its strength; designed to meet federal safety regulations, when broken, it shatters in tiny fragments, reducing the possibility of injury

Thermal Break - An air space or insulating material which prevents the direct coupling of a cold surface to a heated surface

Threshold - A wood or aluminum member, beveled or tapered on each side used with exterior or interior door frames

Tinted Glass - Glass other than clear, with a color cast or tint; typically tinted glass absorbs and blocks heat, and reduces visible light transmittance

Transom - A frame area immediately above a door or window opening and containing fixed glass, an operating sash or panel, or other filler

Triple Glazed - An insulating glass unit consisting of three panes of glass with two internal air spaces

U

U-Value - AKA Heat Transfer Coefficient - Heat transference through a door or window.  A high U-Value indicates greater radiant heat or cold transference through a window or door; a low U-Value indicates less heat transference.  Lower U-Values are desirable for energy efficiency in windows or doors

V

Veneer - A thin sheath of wood applied, usually over a stronger type of wood

Vent - The operating portion of a window that swings or projects in or out

Vinyl - A plastic material used by some window for cladding or entire window units

W

Warm Edge Spacers - Insulating spacers used to seal panes of glass in the manufacture of insulated glass units; edge conductivity

Warp - Any distortion in the plane of a door or window sash itself, and not its relationship to the frame or jamb in which it is to be hung.  The term warp includes bow, cup, and twist:
Bow - A flat wise deviation from a straight line drawn from top to bottom; a curvature along the length of the sash
Cup - A deviation from a straight line drawn from side to side; a curvature along the width of the sash
Twist - A deviation in which one or two corners of the sash are out of plane with the other corners of the sash

Weather Strip - A material which provides a weather tight seal between the door panel or window sash and the frame

Weep - An opening cut into a window sill and/or sash rail to allow water to drain to the exterior

Window Size - Always expressed as width first, then height