Window Glossary

A material used to absorb moisture from within the sealed airspace of an insulation glass unit.

Separately framed pieces or panes of glass. A double-hung window, for instance, often has several lites divided by muntins in each sash. These designs are often referred to as six-over-six, eight-over-one, etc., to indicate the number of lites in each sash. Designs simulating the appearance of separately framed panes of glass are often referred to as SDLs or simulated divided lites. Designs using actual separate pieces of glass are sometimes referred to as TDLs or true divided lites.

A single sheet of material used as the face of a door.

A complete door panel that has not been assembled into a frame.

An area that protrudes from the rood of a house, generally featuring one or more windows.

Use of two panes of glass in a window to increase energy efficiency and provide other performance benefits. May or may not refer to an insulating glass unit.

Window featuring two operable sash that move vertically in the frame.