sash window

Synonym : single or double hung window　 hung window　

Sash windows open and close by moving two or more sashes vertically on rails or grooves set in the window frame. There are two types: one with two operating sashes that move up and down, and another one with a single operating sash. Sash windows evolved mainly in Britain where homes were built of stone, but these days they are also frequently used in the United States.