# Single-hung window

A single-hung window features one fixed upper sash and one operable lower sash that slides vertically-common in early 20th-century British housing and simpler period properties. Unlike double-hung sashes (where both sashes move), single-hung windows are more economical to produce and maintain, though they offer less ventilation flexibility.

In heritage restoration, original single-hung timber windows are often refurbished with draught-proofing and slimline double glazing to improve performance while retaining their authentic character.