Like double hung windows, single hung windows have two window sashes, a top sash that is stationary and a lower sash that can be moved up and down to open and close. This configuration makes single hung windows less expensive and lower maintenance than double hung windows, as there are fewer moving parts and a simpler manufacturing process. The lower sash can tilt inwards for easy cleaning.
Because there is only one moving sash, single hung windows are more energy efficient and offer greater security. This type of window only opens in one direction, providing a lower chance for air leaks, even as the window ages. There are also fewer potential points of failure, as only the bottom sash is operational.