The inside trim piece which lays flat against the wall beneath the stool (interior sill extension). This is a traditional treatment usually associated with only double hung windows.

Awning Window

A window unit which as it opens,  projects outward from the exterior of a building . Hinges are located at the top of the side frame members permitting the sash to simultaneously open both upward and outward, similarly to that of a fabric or metal awning.

Balance (Sash Balance)

A system of cords and pulleys (block and tackle) or spring friction devices which assist in raising double-hung sash and which hold the sash in any intermediate position by counter- balancing the sash's weight. This mechanical device is mounted inside the jamb.

Basic Unit

This is a term given to the fundamental "building block" units of each standard window product line. These units are components of a larger series of standard sizes. Basic units lack exterior trim and installation flanges but are otherwise complete.

Bay Window

A window which projects outward from the exterior of a building. It is composed of three or more individual units. The center unit(s) are parallel to the exterior wall with the side or flanking units aligned at 30 degree or 45 degree angles.

Bow Window

A window projecting outward from the exterior of a building. Composed of four or more units which are aligned in a gently curving contour.

Brick Mould

A form of exterior trim (casing) for windows and doors. In addition to serving as an anchor point for installation of the unit, brick mould provides a boundary for brick or other siding material on the face of the building and for the attachment of hardware (also sometimes called Shake mould).

Capillary Tube

A breather tube device used in insulated glass units for pressure equalization, and consisting of a long tube so tiny that it only permits gases to pass. Interior pressure inside the sealed unit is maintained equal to that outside.

Casement Window

A style of window hinged on both the top and bottom frame members. The construction of a casement is such that the unit swings outward, with the screen on the inside.

Check Rail

The top rail of the lower sash and the bottom rail of upper sash which meet (overlap) when a Double Hung window is closed. (also called meeting rails).

Clad

A designation given to products whose exposed exterior surfaces are sheathed with specially formed aluminum.

Cottage Window

The name of a traditional style of Double Hung window in which a lower sash is larger than its upper counterpart.

Daylight Opening

The portion of a window or door's glazing which is actually visible. A small percentage of a unit's glass will always be concealed as it is mounted in the wood parts.

Dimensional Windows

Custom units created by reducing the size of existing standard units. Dimensional units cannot be smaller in size than the smallest standard size nor larger than the largest standard size.

Direct Set

Refers to window units which do not have sash. The glass is mounted directly into the frame. Units of this type do not operate.

Divided Lites

See "True Divided Lites"

Double Hung Window

A type of window which has two vertically sliding sashes which bypass each other within a single frame. Suspension and operation of the sash is achieved by using a mechanical mechanism powered by springs or balance weights.

Double Hung Replacement System

A packaged system which supplies new sash and operating block and tackle mechanism, and is actuated by springs or balance weights. This system is used for replacement of the sash in those double-hung windows found in older buildings.

Dry Glazing

An alternate method of placing glass in a door or window. No glazing mastic is used.

Drip Cap

A piece of flashing which is contoured for application onto the tops of windows and doors during installation. Its function is to prevent water from seeping down behind the casing and invading the interior of the wall. For Clad windows this flashing is frequently incorporated into the head nailing flange.

Edge Glued

A method of developing wood composites to provide wood parts with greater width. The width is achieved by gluing the smaller component wood pieces edge to edge.

Egress

Literally, an exit (a means of exit). Actual open size determined by local building code.

Energy Panel

This device is a single piece of glass whose edges are protected by an aluminum surround. Its purpose is to increase thermal efficiency on single glazed, 15/16" bar true divided lite units.

Extension Jamb

Wood parts which are nailed to the inside edges of the window jamb to extend it in width and adapt it to a thicker wall.

Frame

The outer components of a window unit-side jambs, head jamb and sill (bottom jamb). These parts "frame" the sash in an operating window and form an immediate boundary for the glass in a direct fixed unit.

Frame Dimension

Measurement from outside of side jamb to outside of side jamb or from outside of head jamb to outside of sill (bottom jamb).

Finger Joint

A method of joining wood parts end to end by machining a series of finger-like grooves in their ends. As they are interlocked, the fingers are bonded together with adhesive.

Flanker

The designation given to units that flank a center picture unit in a double or triple combination or bay window.

Flat Casing

An exterior trim alternative to brick mould. This stock does not have a profile but is simply surfaced flat on four sides.

French Patio Door

A type of swinging patio door which features two operating panels. One panel is designated as the active panel and is equipped with the active handle and latch set. The secondary inactive panel is equipped with flush bolts at head and sill allowing it to be fixed in place or to swing freely. The unit which has just been described is a Traditional or authentic French door.

Center Swinging Patio Door

A center swinging patio door which imparts the feeling of an authentic French door but differs in two important  ways:

    A. The Panel(s) is/are permanently fixed.

    B. The operating panel is not hinged on the side jamb-   instead the panel is hinged from a special structural mull in the center of the unit.

Geometric Windows

These specialty windows are classified as either of of two types:

    A. Straight Line Geometrics, rectangles, triangles, trapezoid, octagons, pentoids, etc.

    B. Radius Geometrics-half rounds, quarter rounds, full rounds, sectors, ellipses, etc.

Glass Size

Actual Glass size, not the glass surface which is visible.

Glazing

Glazing refers to both the act of inserting glass into windows and doors, and to the type of glass in a window or door.

Glazing selections include:

    A. Single Glazing (S.G.). As the name implies, the door or window is glazed with only one pane of glass.

    B. Insulating Glazing or Dual Glazing (1. G.). Two panes of glass permanently bonded together with a spacer to separate them and create a captive air or gas space.

    C. Triple pane-A sealed insulated unit composed of three separate panes of glass with two spacers producing two distinct captive air or gas spaces.

Grilles

Simulated muntins and bars which do not actually divide the individual panes of glass, but rather lay as a complete unit on the surface of a single, undivided pane of glass. Classed as "full surround" all horizontal and vertical tears are linked at the perimeter by a wood surround, or Stick-bars not linked at perimeter (also called grids).

Hopper

Type of window hinged on the sides or bottom that opens at the top by swinging in or out.

Insulated unit

Two pieces (panes) of glazing (glass) separated by a spacer for improved thermal efficiency, and as a secondary option, for the introduction of gas between the panes.

Jamb Liner

A weather-strip device which, in the case of double hung windows, lines the two vertical sides of the sash opening. In addition to providing a tight fit between sashes and the frame, the liner also functions as a mounting site for the block and tackle and coiled spring operating mechanism.

Laminating

Layering of discreet plys or substances.  Laminated glass is manufactured by layering two or more panes of glass together with permanent adhesive.  Laminating implies the permanent joining together of two or more flat surface materials.

Lineal Footage

A dimension expressing length (in feet) only. For example, the width of a unit (in inches) plus the height (in inches) x 2 divided by 12 = the perimeter measurement of the unit in lineal feet.

Low E

A name given to glass when treated to control energy transfer. When referring to heat radiation, objects which readily give off heat are said to have high emissivity. By the application of a microscopically thin, transparent, metallic coating to the object's (glass) surface, its emissivity is dramatically reduced and it subsequently becomes low- emissivity or Low E glass.

Masonry, Clips

Special metal strip accessories designed to secure window or door units in masonry openings.

Masonry, Opening

An opening created in brick, stone or block to accept a window or door unit.

Mullion

The joints which result when window or door units are combined by linking their frames to form multiple units. Mullions may be horizontal or vertical.

Also "mull" In addition to standard mulls, two special forms exist:

    A. Space Mull-A greater space is left between the linked frames to "stretch" the multiple/mulled unit to fill an unusual rough opening. If a jamb extension is included, it surrounds the entire unit.

    B. Stud Pocket Mull - In this method of joining unit frames, a greater than usual space is also created. However, this additional space exists to allow room for a support member (stud) to be placed between the units. In this instance, jamb extensions, if required, surround each individual unit separately.

Muntins

The correct name for the dividing "bars" in True Divided Lite Glazing.

Nailing Fin (Flange)

A strip of sheet material (vinyl, aluminum, steel etc.) which is integral to or fastened to the frame of units. This strip creates a flange which provides a common method for the installation of new construction windows and doors.

Picture Window

A large stationary (fixed) window which is designed for providing a maximum view without obstruction.

Primer

Factory applied coating which is designed to improve acceptance of a paint finish overcoat on the exterior surfaces of wood windows. All exterior wood parts should be primed. Primer is not a sealant and all primed products must have finish coats applied.

Projected Window

Casements and Awnings - project out when open

Rails

The horizontal (top and bottom) members of a window sash or door panel.

Rough Opening

The framed opening in a structure, which is created to accept a window or door unit. The opening should allow  additional room around the frame for correct alignment of the window or door unit.

Sash

A wood perimeter around the glass which allows a degree of independent movement from the frame (not direct set).

Sash has two types of components:

    1) Stiles are the vertical perimeter pieces

     2) Rails are the horizontal perimeter pieces

Sash Opening

The space described by the interior of a window frame. It is bounded by the interior surface of the frames. Jamb liners or hardware adapters must be disregarded. (Primary use of this dimension is for the Replacement Double Hung System).

Sill

The horizontal member which forms the bottom of a window or door frame.

Sill Horn

An extension of a window's sill or sub sill beyond the outer surface of the frame side jambs. This extension provides a bottom contact point for the exterior trim.

Single Hung

Window system where only one glass unit is movable in the plane of the window unit.  The most common type of single hung units have one fixed flat panel, and one movable panel.

Square Foot

A unit of measure for designating area One foot by one foot. Derived from width (in inches) x height (in inches) divided by 144 = area in square feet.

Stool

An interior sill extension used almost exclusively with double hung windows.

Stop

Types:

    Glazing Stop (Glazing Bead)-a small wood strip used to hold glass in place.

    Screen Stop - trim item attached to the frame of window units. Its provides a stop for placement of screens if the sash is to operate.

Subsill

A trim piece for windows. Subsill application (underneath the bottom jamb) simulates the appearance of a true sloped sill and also provides a drainage surface.

Transom

Generally refers to a fixed or operating window unit specifically designated for placement directly above a door or a window.

Stucco Brick Mould

Standard exterior trim which has been modified by having a groove cut in the top rear edge permitting exterior stucco to flow behind the trim.

Unit Dimensions

The dimensions of a window or door unit which are defined in a primed wood unit from outside of exterior trim to outside of exterior trim in both width and height. Unit dimensions for clad units are from outside of frame to outside of frame in width and height.

Vent

Part of window holding glass that opens

Vinyl

A petroleum based product from which window structural members and parts are manufactured, Vinyl can also be liquefied, to produce a protective coating, as in vinyl-clad windows