Windows & Glazing

A full house of uPVC double glazed windows typically costs between 4,000 and 8,000 pounds for a three-bedroom semi-detached house. Individual windows range from 300 to 800 pounds depending on size and opening style. Prices include supply, fitting, and building regulations certification.

Triple glazing costs around 20 to 30 percent more than double glazing but delivers a U-value of around 0.8 compared to 1.2 for standard double glazing. The energy savings are modest for most UK homes, making it most worthwhile for north-facing rooms, noisy locations, or new builds where the price premium is smaller.

Most window replacements fall under permitted development and do not need planning permission. However, if your home is a listed building or in a conservation area, you will likely need consent. The installer must be FENSA registered or you will need separate building control sign-off.

Modern double glazed sealed units typically last 20 to 25 years. uPVC frames can last 25 to 35 years with minimal maintenance. Signs that replacement is needed include misting between panes, draughts around seals, difficulty opening or closing, and visible frame deterioration.

No UK scheme funds replacement windows on their own. The Great British Insulation Scheme closed on 31 March 2026 and only ever covered insulation, never glazing. ECO4 runs to 31 December 2026 in Great Britain only and targets insulation and heating for households on qualifying benefits; glazing is included only where it forms part of a wider whole-house retrofit. Glazing is also standard-rated for VAT at 20%, as HMRC lists double and secondary glazing as excluded from the energy-saving materials zero rate.