Casement Windows across the UK

Casement Windows - what to expect

Casement windows are the UK's default replacement choice - hinged on the side, opening outward, and available in uPVC, aluminium or timber. If your existing frames are pre-2005 or single-glazed, replacing them with A-rated casements typically pays back in energy savings within 8-12 years.

The single biggest price driver is glass area, not frame material - a 1200x1200mm casement costs roughly the same in uPVC or basic aluminium, but doubles for triple-glazed or thermally-broken aluminium. Standard installs use argon-filled double glazing with a warm-edge spacer; upgrading to triple glazing adds around 15% for a marginal thermal gain in most UK climates.

Installation is usually a 1-2 day job for a whole house (6-10 windows), done by a two-person FENSA-registered team. FENSA registration matters because it self-certifies compliance with Building Regulations Part L (thermal performance) - without it you'd need Building Control sign-off separately, which adds cost and delay.

Typical UK price range for casement windows: £350 - £900 installed. Actual figures for your city sit on the city page below.