Choosing Windows for a 1930s Semi

The signature 1930s window is a metal-framed (Crittall) casement with slim horizontal glazing bars and small side panels — often set into a curved or angular bay. Timber casements with similar bar patterns appeared on lower-cost builds. Both share slim sightlines and horizontal proportions.

Modern uPVC flush casements with horizontal glazing bar overlays reproduce the 1930s look effectively. Bar spacing matters — go with the historical proportions (three or four horizontal panes per sash) rather than modern vertical Georgian bar patterns which are wrong for the period.

Cream, heritage green (Chartwell), Chalk White and dark grey work well. Bright modern white is period-inappropriate. Dual-colour options (heritage exterior, white interior) let you satisfy the street elevation while keeping the interior bright.

1930s bays are usually load-bearing and often tile-hung above. Replacement needs to maintain the structural support of the bay roof. Some 1930s bays have a small mid-height mullion or transom that should be reproduced faithfully — losing it changes the proportions.

Chunky sculptured uPVC in bright white with vertical Georgian bars — the most common wrong replacement on 1930s semis, and the reason so many otherwise-nice houses look downgraded. Ask specifically for flush casement profiles, heritage colours and horizontal (not Georgian) bar layouts.