Sash vs Casement Windows

Sash windows are Georgian and Victorian — vertical sliding sashes counterbalanced by weights or (in modern versions) spring balances. Casements are Tudor to Edwardian and post-war — side-hung sashes that swing outward. Both are properly 'British' but belong to different eras.

Georgian townhouses and Victorian terraces almost always had sash windows originally. Casements installed on those properties (a common 1980s replacement) rarely look right. Cottage and post-war properties suit casements. The single biggest driver of the correct choice is the property's own architectural period.

Sash windows offer stack ventilation — top down and bottom up simultaneously, drawing cool air in at the bottom and expelling warm air at the top. That's a genuinely useful summer feature. Casements provide a single opening area but the aperture is usually larger.

Modern uPVC sash windows cost 30–60% more than equivalent casements because of the spring balance mechanism and multi-part sash construction. Timber sash windows require repainting every 6–8 years. Casements in uPVC are the low-maintenance, low-cost mainstream option.

uPVC and timber-alu sash windows now reproduce the deep sightlines and slim glazing bars of true Georgian sashes convincingly. Ask for a 'deep bottom rail' profile and horns on the meeting rail — those are the details that separate an authentic reproduction from a generic 'sash-alike'.