Extension blind stop:
Molded window frame member, usually the same thickness as the blind stop and united with it, thus increasing the width of the blind stop, in order to close the gap between the window frame and the rough opening in the house frame. Used to attach the window frame to the wood framing. Also known as blind stop extender or blind casing.
Extension casement hinge:
Hinge for a casement window which provides clearance for cleaning the two sides of the sash from the inside.
Extension jamb:
A board used to increase the depth of the jambs of a window frame to fit a wall of any given thickness.
Extrusion:
A form produced by forcing metal or vinyl through a die. Window and door frames are often clad with extrusions.
Eyebrow windows:
Low, inward-opening windows with a bottom-hinged sash. Usually attic windows built into the top molding of the house, the units sometimes are called “lie-on-your-stomach” windows or slave windows. Often found in Greek Revival and Italianate houses.
Face glazing:
Common glazing set with putty in a rabbetted frame.
Fanlight (also sunburst light; fan window; circle-top transom):
A half-circle window over a door or window, with radiating bars.
Fenestration:
The arrangement, proportioning and design of windows and doors in a building.
Finger-jointing:
A wood end-joint formed by a set of interlocking fingers, coated with adhesive and meshed together under pressure.
Fire window:
Window with fire-endurance rating specified for the location.
Fixed light (also fixed sash):
Window or sash which is non-operative or non-venting.
Foil:
Lobe on a leaf-shaped curve formed by the cusping
of a circle or arch. The number of foils involved is indicated by a prefix, e.g., tre-foil (3); quatre-foil (4), etc. Foils are found in windows of Gothic Revival churches and houses.
Folding casement:
Casement windows hinged together so they may fold into a confined space.
Frame:
An enclosure or combination of parts which surround a window sash or door panel.
French sliding doors:
A sliding door which has wider panel members around the glass, thus giving it the appearance of a hinged French door.
French window:
Two casement sash hinged on the sides to open in the middle; sash extends to the floor and serves as a door to a porch or terrace.
Geometric window:
A fixed framed window made up of 2 or more angles (i.e., pentagon or trapezoid).
Georgian window:
A double-hung window.
Glazing:
The glass panes or lights in the sash of a window. Also the installation of glass in a window.
Glazing bead (also glass stop):
Removable trim that holds glass in place.
Glazing clip:
Metal clip for holding glass in a metal frame while putty is applied.
Glazing channel:
Groove cut into sash for acceptance of glass.
Glazing gasket:
Special extruded plastic shape for attaching window glass to metal or masonry wall openings. It also serves as a cushion and insulator.
Gothic-head window:
Window topped with a pointed arch.
Grille (or muntin bar):
Usually removable for easy cleaning, grilles give the appearance of a divided window pane.
Guillotine window:
The first double-sash window, with only one movable sash and no counterweights or balancing system. A peg was inserted through a hole in the movable sash and into a corresponding hole in the frame. Its tendency to come slamming down led to the colorful name.
Hanging sash (also hung sash):
Sash hung on a cord connected to a counterweight.
Head casing:
Top or upper member of any element or structure. In windows, it refers to the top of the frame.
Head flashing:
Flashing installed in a wall over a window.
Header:
Supporting member or beam above window opening which transfers building weight above to the supporting wall structure on each side of the window.
Head jamb (also head):
All of the horizontal members that make up the top of the window or door frame.
Hinged French doors:
Hinged door(s) which have wider panel members around the glass.
Hit-and-miss window:
Two-part window with the lower sash containing movable ventilation panels.
Hopper light (also hopper vent and hopper ventilator):
Inward-opening ash hinged at the bottom.
Impact resistant glazing:
Glass specifically manufactured to withstand impacts from airborne objects or forced entry. Usually a type of laminated glass often used in coastal areas impacted by hurricanes.
Insulating glass:
A combination of 2 or more panes of glass with a hermetically sealed air space between the panes. The space may be filled with an inert glass such as argon.
Interior glazes:
Glazing installed from inside of the building structure.
Jal-awning window (also awning window):
Windows with several out-swinging, awning type units that pivot near the top of the glass and operate in unison.
Jalousie:
A shutter-type window with slats, which are either fixed or adjustable.
Jalousie windows (also louvered windows):
A window composed of overlapping narrow glass, metal, or wooden louvers, operated with a crank handle for adjusting the louver angles.
Jamb:
The vertical members at the side of the window or door frame.
Jamb depth:
Width of the window frame from inside to outside.
Jamb liner:
The plastic or metal track installed in the jambs of the window in which the window sash slide.