window replacement specialists in London
Homeowners in London use Pro-Fit Window Systems to collect free window replacement quotes from trusted local installers. Every company in our Greater London network is FENSA-registered and independently rated.
We connect you with up to 3 FENSA-registered window replacement installers near London who will each provide a free, no-obligation quote. In London, comparing multiple quotes saves homeowners an average of £500–£1,500.
Window Replacement prices in London 2026
The table below shows typical installed prices for window replacement in London and the Greater London area. Prices vary by specification — get an exact quote using our free tool.
| Window Type | From (installed) | Up to (installed) |
|---|---|---|
| Casement (single) | £438 | £875 |
| Casement (large) | £625 | £1,125 |
| Sash Window | £750 | £1,375 |
| Bay Window (3-panel) | £1,500 | £4,000 |
| Tilt & Turn | £500 | £938 |
* Prices are estimates for London based on current market data. Your exact quote will depend on window size, specification and chosen installer.
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Get Quotes in London →FAQs — Window Replacement in London
How much does window replacement cost in London?
In London, you can expect to pay from £438 for a standard casement window installed, up to £4,000 for a full bay window. Prices in Greater London are slightly above the national average. The best way to get an accurate price is to compare quotes from local FENSA-registered installers using our free tool.
How long does window installation take in London?
The time required depends on how many windows are being installed. In London, a single window can be replaced in 2–4 hours, while a whole-house installation typically takes 2–3 days. Your installer will confirm the schedule during their free property survey.
How do I know your London installers are trustworthy?
Yes. Every installer in our London network is FENSA registered, which means they are certified to install replacement windows in compliance with UK Building Regulations. FENSA registration also provides a 10-year insurance-backed guarantee on all installations.
Do I need planning permission for new windows in London?
In most cases, replacing windows like-for-like in London does not require planning permission — it falls under permitted development. However, if you live in a conservation area or listed building in Greater London, you may need consent. Your installer will advise you during the free survey.