Quick answer: Double glazing a typical home costs a modelled UK average of £5,530 in July 2026, ranging from £3,594 to £8,572. It could save up to £279 a year (estimate) — a modelled payback of around 20 years, so most buyers weigh comfort, noise and property value alongside the bills.
We are deliberately unromantic about glazing: on pure energy savings it is one of the slower-payback upgrades in our UK Home Energy Cost Index, and this page shows exactly why. For frame materials, glass options and whether your current windows are the real problem, start with the double glazing guide.
Key double glazing statistics for 2026
- A typical whole-home double glazing installation costs a modelled UK average of £5,530 — Green Reach Energy Cost Index, July 2026 (modelled).
- Most double glazing projects fall between £3,594 and £8,572 depending on window count and frame choice — Green Reach Energy Cost Index, July 2026 (modelled).
- London leads the regional table at a modelled £6,636; the South East follows at £6,194 — Green Reach Energy Cost Index, July 2026 (modelled).
- Northern Ireland is the cheapest region at £5,088, with the North East next at £5,143 — Green Reach Energy Cost Index, July 2026 (modelled).
- The London–Northern Ireland spread is £1,548, roughly 30% — Green Reach Energy Cost Index, July 2026 (modelled).
- North West installations average a modelled £5,254; Wales £5,198; Scotland £5,309 — Green Reach Energy Cost Index, July 2026 (modelled).
- New double glazing could save a typical household up to £279 a year (estimate) — Green Reach Energy Cost Index, July 2026 (modelled).
- Modelled simple payback is around 20 years — comfort and noise, not bills alone, usually justify the spend — Green Reach Energy Cost Index, July 2026 (modelled).
- Double glazing costs nearly four times as much as a typical insulation project but delivers a smaller modelled annual saving — Green Reach Energy Cost Index, July 2026 (modelled).
- Windows keep in heat bought at 7.33p/kWh for gas under the July–September 2026 Ofgem price cap.
- The typical dual-fuel bill is £1,862 a year this quarter, so a £279 saving would trim roughly 15% off it — Ofgem, July 2026 (modelled comparison).
Double glazing costs by UK region
Fitting windows is skilled labour, so the regional index applies in full. Figures model a typical whole-home installation; a single bay or a couple of casements will cost proportionally less.
| Region | Modelled average installed cost | vs UK average |
|---|---|---|
| UK average | £5,530 | — |
| London | £6,636 | +20% |
| South East | £6,194 | +12% |
| East of England | £5,862 | +6% |
| South West | £5,806 | +5% |
| West Midlands | £5,419 | −2% |
| East Midlands | £5,364 | −3% |
| Scotland | £5,309 | −4% |
| Yorkshire & the Humber | £5,254 | −5% |
| North West | £5,254 | −5% |
| Wales | £5,198 | −6% |
| North East | £5,143 | −7% |
| Northern Ireland | £5,088 | −8% |
All modelled figures on this page come from the Green Reach Energy Cost Index — our July 2026 estimates built from national installed-price baselines and regional labour indices, not quotes for your specific home. Real double glazing prices vary with property type, spec and installer, so treat these as a starting point and read how we calculate costs for the full method and its limitations.
Grants: what exists (and what doesn’t)
There is no dedicated national double glazing grant as of July 2026, and windows are not on the 0% VAT list that covers solar, batteries, heat pumps and insulation. The main possibility for lower-income households is the Warm Homes: Local Grant, which funds energy-performance upgrades of up to £30,000 per home for eligible EPC D–G properties — worth checking through our complete 2026 grant round-up. The U-value entry explains the number to compare on any window quote.
To see how new windows stack up against cheaper heat-saving measures for your home, run both through the savings calculator.
Download the dataset
The full Cost Index — 9 upgrades × 12 UK regions, July 2026 — as CSV: gre-cost-index.csv. Free to reuse with attribution (CC BY 4.0) — please credit Green Reach Energy and link the methodology. Figures are modelled estimates, not quotes.