Secondary glazing in Westminster

Looking for secondary glazing in Westminster? Compare free, no-obligation quotes from vetted local installers in your area. Typical prices in Westminster sit around from £438 depending on unit count and specification.

Secondary glazing is a separate internal window fitted inside your existing primary window, and it's the compliant answer to a set of problems that regular replacement can't solve: listed buildings, Grade II* fronts, conservation areas with strict Article 4 controls, and mid-terraces on busy main roads where noise is the bigger issue than thermal loss. Because it doesn't touch the primary window, it doesn't need Listed Building Consent in the vast majority of cases - a genuine 'yes' where the answer would otherwise be a slow, expensive planning nightmare.

Prices depend on the frame material (aluminium is standard, timber is available for internal aesthetic match on period rooms), the opening style (fixed, horizontal slider, lift-out, vertical sash to match a Georgian primary), and the glass. A typical aluminium horizontal slider on a 1.2m x 1.2m opening is £350-£550 fitted; upgrade to 6.8mm acoustic laminated glass (the meaningful noise-reduction spec) and you're at £550-£800; a bespoke timber vertical sash pair to match a Georgian window inside a Grade II listed drawing room can run £950-£1,600.

Popular specs for secondary glazing

Secondary glazing standard spec: aluminium frame powder-coated to match interior joinery colour, minimum 100mm cavity from primary window, 6mm toughened or 6.8mm acoustic laminated glass, magnetic or brush perimeter seals, horizontal slider or lift-out openers, discrete telescopic prop on lift-outs, 10-year system guarantee. Compliant on listed buildings without consent in most authorities - confirm locally.