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Updated September 2026 with current UK prices.
Double glazing costs £500–£900 per window for standard uPVC in 2026, and £4,000–£15,000 to replace every window in a typical house. Aluminium and timber cost more; sash windows cost more again. The biggest factors are frame material, window style and size, how many windows you replace at once, and where you live.
2026 double glazing prices at a glance
| What you're paying for | 2026 price (supply and fit) |
|---|---|
| uPVC casement window | £500–£900 each |
| uPVC sash window | £900–£1,500 each |
| Aluminium window | £800–£1,600 each |
| Timber window | £1,200–£2,000+ each |
| Whole house, all windows | £4,000–£15,000 |
Typical UK supply-and-fit prices including VAT, based on published UK trade price guides and checked in September 2026. They are guide prices, not quotes: always compare at least three written quotes. Get free quotes from local installers.
How much does double glazing cost for a 3-bed house?
A three-bedroom semi usually has 8–12 windows. Replacing them all costs roughly:
| Specification | Typical total |
|---|---|
| White uPVC casements, standard energy rating | £4,000–£6,500 |
| Coloured or woodgrain uPVC, A-rated glass | £6,500–£9,000 |
| Aluminium or timber, or triple glazing | £9,000–£15,000+ |
Replacing all the windows in one job is cheaper per window than doing a few at a time, because survey, scaffolding and travel costs are shared.
Double glazing prices by frame material
| Material | Price per window (fitted) | Good for | Trade-offs |
|---|---|---|---|
| uPVC | £500–£900 | Best value, low maintenance | Chunkier frames |
| Aluminium | £800–£1,600 | Slim frames, large glass areas, long life | Higher cost |
| Timber | £1,200–£2,000+ | Period homes, conservation areas | Needs repainting every few years |
| Composite (timber inside, aluminium outside) | £1,200–£2,500+ | Timber look without the upkeep | Most expensive, fewer makers |
Prices by window style
- Casement (side or top-opening): the cheapest and most common, within the ranges above.
- Tilt and turn: usually 10–20% more than an equivalent casement.
- Sash: £900–£1,500 in uPVC and £1,500+ in timber, because of the sliding mechanism.
- Bay and bow windows: £2,500–£6,000 each, as they need several frames and sometimes structural work.
Is triple glazing worth the extra cost?
Triple glazing typically adds 20–40% to the price of each window. It makes most sense on very exposed or noisy sites, on low-energy new builds, and if you plan to stay for many years. For most homes replacing single glazing or old double glazing, good-quality double glazing gives most of the benefit for much less money. Frame quality and careful fitting matter as much as the number of panes.
Should you repair or replace sash windows?
For period homes, restoring original sashes can cost less than replacement and is often expected in conservation areas:
- Draught-proofing existing sashes: roughly £150–£300 per window.
- Full restoration (new cords, weights, repairs, decoration): roughly £800–£1,500 per window.
- Replacement double-glazed sashes: from about £900 in uPVC, £1,500+ in timber.
Check with your council before replacing windows in a listed building or conservation area, as consent may be needed.
Building Regulations and certificates
Replacement windows in England must meet Building Regulations Part L: since June 2022 the limit for a replacement window is a U-value of 1.4 W/m²K (lower is better). Most modern double glazing meets this comfortably.
The work must either be done by an installer registered with a competent person scheme such as FENSA or CERTASS, who certifies it for you, or be approved by your council's building control. Keep the certificate: you will need it when you sell. Rules differ slightly in Wales, Scotland and Northern Ireland.
How long does installation take?
Most houses take 2–5 days: old frames out, new frames in and sealed, then internal making good. Allow extra time if rotten lintels or other problems are found once old frames come out.
How to check a double glazing company
Windows usually come with a 10-year guarantee, so it matters that the company will still be around. From our research on Companies House data:
- There are about 5,800 glazing companies registered in the UK (September 2026).
- Only 53% of glazing companies set up in 2019–2020 were still trading five years later (Trade Survival Index).
- 9.7% of glazing companies were proposed for strike-off or in insolvency in September 2026 (Trade Index).
Before you pay a deposit:
- Check the company's status and age on HouseJester or Companies House. Be wary of a status of proposal to strike off.
- Confirm FENSA or CERTASS registration.
- Ask for an insurance-backed guarantee, which still protects you if the installer stops trading.
- Get a written quote that names the exact product, glass and U-value.
- Avoid "today only" discounts; a genuine quote stays valid for weeks.
Why prices vary by region
London and the South East are usually 15–30% above the national average because of higher labour costs and access and parking. Rural homes can cost more because of travel. The Midlands and the North tend to be closer to average.
How to save money on double glazing
- Replace all windows at once rather than a few at a time.
- Choose white uPVC casements: colours, woodgrain finishes and decorative glass all add cost.
- Book in quieter months (late autumn and winter) when installers may have more flexibility.
- Compare at least three written quotes for the same specification.
Double glazing cost FAQs
How much does one double glazed window cost? A standard uPVC casement window costs about £500–£900 supplied and fitted in 2026. Small windows can be less; large or specialist windows more.
How much does double glazing cost for a whole house? Usually £4,000–£15,000, depending on the number of windows, material and specification. A typical 3-bed semi with white uPVC is £4,000–£6,500.
Is aluminium better than uPVC? Aluminium gives slimmer frames and lasts longer but costs more. uPVC is the best value and performs well thermally. Both meet Building Regulations when properly specified.
Do I need planning permission for new windows? Usually not for like-for-like replacements on a house. You may need consent for listed buildings, conservation areas with an Article 4 direction, and some flats.
Sources and further reading
Browse windows and doors companies on HouseJester to find installers near you.
This article was created with AI assistance and reviewed by the HouseJester editorial team for accuracy and relevance.
Written by
James Hartley
Home Improvement Writer
A former building contractor turned journalist, James brings hands-on experience to every article. He specialises in home improvement projects, building regulations, and helping homeowners navigate renovation work with confidence.
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