Hung-slider windows

Single hung 

This window opens with the lower sash sliding vertically while the upper sash remains stationary. 

Single slider 

Sashes are side-by-side with one sash sliding open horizontally while the other remains stationary. 

Double hung

These windows operate with both the upper and lower sashes sliding open vertically.

Double slider

Sashes are side-by-side with both sashes able to slide open horizontally.