How much do replacement windows cost in the UK?
Updated 19 October 2026 · Reviewed by Steve Wolfe
Replacing all the windows in a typical three-bed semi with white uPVC double glazing costs about £4,500 to £12,000 including VAT, depending on how many there are and their size and style. A single uPVC casement window costs about £350 to £650 fitted. Sash, bay and timber windows cost more.
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Typical costs
Typical UK prices including VAT, supplied and fitted with the old windows taken away.
| Type | Typical cost |
|---|---|
| Whole house, uPVC casements £4,500–£12,000 A three-bed semi or similar, about 8 to 12 windows. On site: 1 to 3 days | £4,500–£12,000 |
| One uPVC casement window £350–£650 The most common type, hinged at the side or top. Bigger windows cost more. | £350–£650 |
| One uPVC sash window £700–£1,450 Sliding sashes, as in many period houses. Around half as much again as a casement. | £700–£1,450 |
| One timber sash window £1,200–£3,600 Made-to-measure timber, often needed in conservation areas and listed buildings. | £1,200–£3,600 |
| One bay window £1,500–£2,600 Three or more sections, often with extra work to the frame and roof. | £1,500–£2,600 |
Our reading of the published guides listed under Sources, rounded and including VAT. Scaffolding, new lintels and plastering around the frames cost more.
What changes the price
- How many, and how big. Most of the cost is per window, and bigger windows cost more. Checkatrade puts a small uPVC casement at about £300 to £400 before VAT and a large one at about £450 to £570.
- The style. Casements are the cheapest. Tilt and turn windows cost about a quarter more, sash windows about half as much again, and bay windows up to twice as much.
- The material. White uPVC is cheapest. Woodgrain and coloured uPVC, aluminium, composite and timber cost more.
- The glass. A-rated double glazing is standard now. Triple glazing, acoustic or obscure glass cost extra.
- Access and the openings. Upstairs windows that need scaffolding, rotten or missing lintels, or making good around the frames add to the bill.
Is it worth replacing your windows?
It depends what you have now. Replacing single glazing makes a real difference to warmth and noise, and saves about £85 a year on bills according to the Energy Saving Trust. On a set of windows costing about £4,800, that's a payback of more than 50 years on bills alone. Replacing old but working double glazing saves much less, so it's usually about comfort, condensation, security or looks rather than money.
Before you get quotes
- Count your windows and measure them roughly, noting any bays, sashes or very large ones.
- Decide on style, material and colour, so every quote prices the same thing.
- Check the installer is registered with FENSA, Certass or a similar scheme, and ask about the guarantee.
- Ask whether scaffolding, taking away the old windows and making good inside are included.
- Get two or three quotes. Window prices vary a lot between firms.
An example Ballpark
What Ballpark gave for this job on 16 October 2026. It’s an example we worked out, not a customer’s price.
Replace all the windows in a three-bed semi in Birmingham with white uPVC double glazing, eight windows of normal sizes.
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Standard casement windows £3,750–£5,500
Eight white uPVC double glazed windows, fitted, with the old ones removed and taken away.
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Mid-range energy ratedClosest to the job £4,750–£7,000
Eight white uPVC A-rated windows with better hardware, fitted, with the old ones taken away.
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Premium finish £6,500–£9,500
Eight white uPVC windows with flush sashes or a mix of styles, upgraded glass and trims, fitted.
Based on
- Eight normal-sized windows, no bay windows
- Fitted by a FENSA-registered installer
- Plastering and internal finishing are only minor
- Prices include VAT
What a trade will ask you
Have answers ready and your quotes (and your ballpark) will be closer to the real price.
- How many windows, and roughly what sizes?
- What are they now? Single glazed, old double glazing, timber or uPVC?
- What style? Casement, sash, tilt and turn or bay?
- What colour and material? White uPVC, woodgrain, timber or aluminium?
- Is the house in a conservation area, or listed?
- Will upstairs windows need scaffolding?
Common questions
How much do new windows cost for a three-bed house?
About £4,500 to £12,000 including VAT for white uPVC double glazing, depending on the number and size of the windows. Checkatrade puts 12 uPVC casement windows at about £7,500 before VAT, and the Energy Saving Trust puts a set of A-rated windows for a semi at around £4,800.
Will new windows save me money on bills?
Some, but they take a long time to pay for themselves. The Energy Saving Trust estimates that replacing single glazing with A-rated double glazing in a semi saves about £85 a year in Great Britain, and less if you already have double glazing. Comfort, noise and condensation are often better reasons to replace them.
Do I need planning permission for new windows?
Not usually, if the new windows look similar to the old ones. You may need permission in a conservation area, and listed buildings need listed building consent. Flats can have different rules, so check with your council.
What is a FENSA certificate?
Replacement windows have to meet building regulations. Installers registered with a scheme such as FENSA or Certass can certify their own work and register it, and you should get a certificate. Keep it, as you'll need it when you sell.
How long does it take to replace windows?
About 1 to 2 hours per window, so 1 to 3 days for a typical three-bed house, plus any making good inside.
Are your prices including VAT?
Yes. Every price on this page includes VAT. Many window guides quote before VAT, so check which you're comparing.
What would yours cost?
Describe your new windows and get a ballpark for your house in a couple of minutes. Free, and you don’t have to get quotes.
Get my ballparkSources
- Checkatrade, new windows cost guide (Jul 2026). Prices per window and for a three-bed house before VAT, sash, tilt and turn and bay windows, timescales and certification
- Energy Saving Trust, energy efficient windows and doors (May 2026). Cost of a set of A-rated windows for a semi, and the yearly saving
- Checkatrade, double glazing cost (May 2026). uPVC window prices and whole-house costs