Use this free calculator to estimate what double glazing costs for your home in 2026. Pick your window style, how many you need, your frame material and your region, and you will get a realistic fitted price range built from the same guide prices as our detailed cost guides. Then, before you spend a penny, check whether funding could cover some or all of it.
Cost calculator
Typical 2026 fitted prices, including VAT
How the calculator works out your estimate
The estimate is built from typical 2026 fitted guide prices, the same figures used across our uPVC window cost guide and door cost guide. Each window style has a base fitted price, bays are priced separately because of their size and structural work, aluminium and coloured finishes carry their usual premiums, and a regional factor reflects how labour rates differ across the UK.
| Item | Typical 2026 fitted price (white uPVC) |
|---|---|
| Casement window | £375 to £500 |
| Flush casement window | £500 to £680 |
| Tilt and turn window | £500 to £650 |
| Sliding sash style window | £700 to £950 |
| Bay window (3 to 5 panes) | £1,500 to £3,000 |
| External door (uPVC to composite) | £650 to £1,900 |
Aluminium frames typically add 30 to 40 percent; coloured or woodgrain uPVC adds 10 to 15 percent. London and the South East price above the national average, the North and Northern Ireland below it.
Before you budget for the full amount: homeowners with windows five years old or older can check in under 60 seconds whether a grant or funding could cover some or all of the cost. Launch the funding checker.
What can change the final quote
A calculator can price the windows; it cannot see your house. The survey items that most often move a final quote are access (upper floors needing scaffold or towers), replacement lintels where old frames were structural, upgraded glass specifications such as acoustic or solar-control units, and non-standard sizes or shapes. None of these are reasons to pay over the odds, but they are why two identical-looking houses can get different quotes.
Ways to bring the cost down
Check funding first: the Help 2 Buy Windows grant can cover qualifying homes, and partner funding spreads the cost for those who do not qualify. The Help 2 Buy Windows grant has nothing to do with the UK government; it is funded 100% by Help 2 Buy Windows through the sale of leads to our clients. Beyond funding, whole-house jobs price better per window than one-offs, white uPVC is the best-value specification, and like-for-like quotes from two or three installers keep everyone honest. Our guide to buying double glazing online covers the supply-only route too.
Frequently asked questions
How much does double glazing cost in 2026?
As a typical 2026 guide, a fitted white uPVC casement window costs £375 to £500, and a whole three-bedroom semi with eight windows costs around £3,500 to £4,800. Sash styles, bays, aluminium frames and coloured finishes all push the price up. The calculator on this page gives you a tailored range for your own mix of windows and doors.
How accurate is this double glazing cost calculator?
It uses the same typical 2026 fitted guide prices as our detailed cost guides, adjusted for your window style, material, finish and region, and shows a range rather than a single figure. Treat it as a realistic budgeting range: your final quote depends on survey findings such as access, lintels and glass specification.
Does the estimate include fitting and VAT?
Yes. The ranges are fitted prices including installation by a registered installer and VAT, based on typical 2026 UK guide rates. Supply-only prices are usually 30 to 40 percent lower, but you then pay a fitter separately and must arrange Building Regulations sign-off.
What is the cheapest way to pay for double glazing?
Check funding before you borrow or spend savings. Qualifying homeowners with windows five years old or older can apply for the Help 2 Buy Windows grant, and those who do not qualify can be offered partner funding that spreads the cost, often with no deposit. The Help 2 Buy Windows grant has nothing to do with the UK government; it is funded 100% by Help 2 Buy Windows through the sale of leads to our clients.
Why do double glazing quotes vary so much?
Labour rates vary by region, with London and the South East above the national average and the North and Northern Ireland below it. Beyond that, the biggest swings come from window style, frame material, coloured or woodgrain finishes, glass specification and access. Getting the same specification quoted like for like is the only fair comparison.