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Window

A window is an opening in a wall or roof, usually filled with glass in a frame, that lets in light and air and allows people to see outside. Most windows can be opened, though fixed windows cannot.

Common residential types include single-hung and double-hung windows that slide vertically, sliding windows that move sideways, casement windows hinged at the side, and awning windows hinged at the top. Bedroom windows usually have to meet egress rules on opening size and sill height so they can serve as an emergency exit.

Floor plans show a window as a thin break in the wall line, often with one or more lines across the opening. Windows do not change floor area, but their width and position appear in wall dimensions. See window symbols.