Double glazing cost in 2026
The short answer
- £500 to £1,250 a window for standard uPVC double glazing, supplied and fitted
- £8,000 to £15,000 for a 3 bed house; around £4,800 for a set of A-rated windows for a semi (Energy Saving Trust)
- £85 a year saved replacing single glazing in a semi; secondary glazing suits listed homes
Double glazing typically costs £500 to £1,250 a window for standard uPVC, and £8,000 to £15,000 for a 3 bed house, according to Checkatrade. The Energy Saving Trust puts a set of A-rated windows for a semi at around £4,800, saving about £85 a year where they replace single glazing. Prices are typical ranges, not quotes.
Double glazing cost per window
£500 to £1,250 for a standard uPVC casement window, more for sash, sliding and bay windows.
| Window | Typical range, supplied and fitted | Average |
|---|---|---|
| uPVC casement window | £500 to £1,250 | £1,000 |
| Sash window | £700 to £1,500 | £1,200 |
| Sliding window | £600 to £1,400 | £1,100 |
| Tilt and turn window | £600 to £1,400 | £1,100 |
| Bay window | £1,100 to £4,000 | £2,500 |
Read the detail
A standard white uPVC casement window costs about £500 to £1,250 supplied and fitted, according to Checkatrade's May 2026 price guide. Sash, sliding and tilt and turn windows cost more, and a bay window £1,100 to £4,000.
Checkatrade ballpark prices, updated May 2026, for double glazed windows supplied and fitted. Coloured or timber frames, security features and access needing scaffolding add to them. Prices vary by region and by job, so treat these as typical, not quotes.
For frame materials, triple glazing and what moves the price of a single window, see double glazing cost per window.
For a whole house
£8,000 to £15,000 for a 3 bed house, or around £4,800 for a set of A-rated windows for a semi by the Energy Saving Trust's figure.
Read the detail
A typical 3 bed house of 8 to 12 windows costs about £8,000 to £15,000 to double glaze, in Checkatrade's guide. The Energy Saving Trust gives a lower figure: a set of A-rated windows for a semi-detached house typically costs around £4,800.
The two are not like for like: the Trust's is a set of A-rated windows for a semi, and Checkatrade's is for a house of 8 to 12 windows across the range of frames people buy. Get three quotes for your own windows, as the Trust recommends.
Triple glazing
Around 20% more than double glazing, worth it in cold or noisy places.
Read the detail
Triple glazing costs around 20% more than double glazing, according to the Energy Saving Trust: on its £4,800 figure for a semi, about £5,760. The Trust says the energy, sound and security benefits can make it worth it in a particularly cold or noisy place.
Secondary glazing: the cheaper alternative
Usually cheaper, and it keeps the original windows, which suits listed buildings.
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Secondary glazing fits a second pane on the inside of the existing window. The Energy Saving Trust says it can be cheaper than new windows, depending on the type: a plastic film you fit yourself is cheapest but gives the least benefit; magnetic panels can be removed and refitted; permanent secondary glazing in custom wooden or uPVC frames costs more but can be more energy efficient than replacing the windows.
It suits listed buildings and conservation areas, because it keeps the original windows. The Trust says reversible secondary glazing does not usually need listed building consent, and the Planning Portal lists internal secondary glazing as permitted development. We found no current published price survey for secondary glazing that we could check, so we give no price.
What double glazing saves
About £85 a year in a semi replacing single glazing, so the payback is long.
Read the detail
Replacing the single glazing in an entirely single glazed semi-detached house with A-rated double glazing saves about £85 a year on energy bills in Great Britain, and £140 in Northern Ireland, according to the Energy Saving Trust, and 290 kg of carbon dioxide a year in Great Britain.
On a £4,800 job that is about 56 years to pay back, longer than the 20 to 35 years the Trust says double glazing lasts. The Trust's figure is for replacing single glazing; we have no sourced figure for replacing old double glazing. Our guide to whether double glazing is worth it sets out the real reasons to buy it.
Planning and building rules
Similar looking replacements need no planning permission. Listed buildings need consent; use a competent person scheme installer.
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Replacement windows of a similar appearance to the house's existing ones are permitted development, so they do not need planning permission, according to the Planning Portal. A new bay window counts as an extension and may need permission, and upper floor side windows must be obscure glazed and either fixed shut or open only above 1.7 metres from the floor.
A listed building needs listed building consent for any significant work, and in a conservation area or where the council has made an Article 4 Direction there may be extra restrictions, so check with the council first. Your installer should belong to a competent person scheme so the windows meet building regulations; if not, you need building control approval before they go in. In Scotland, check with the council's building standards office whether you need a building warrant.
Frequently asked questions
How much does double glazing cost per window?
About £500 to £1,250 for a standard uPVC casement window, supplied and fitted, and £700 to £1,500 for a sash window, according to Checkatrade's May 2026 guide.
How much does it cost to double glaze a 3 bed house?
About £8,000 to £15,000 for 8 to 12 windows in Checkatrade's guide. The Energy Saving Trust puts a set of A-rated windows for a semi at around £4,800.
How much does double glazing save a year?
About £85 a year replacing all the single glazing in a semi-detached house with A-rated double glazing, according to the Energy Saving Trust.
Is secondary glazing cheaper than double glazing?
Usually, depending on the type, the Energy Saving Trust says. It keeps the original windows, which suits listed buildings and conservation areas.
Do I need planning permission for new windows?
Not for replacement windows that look similar to the existing ones on a house, which are permitted development. Listed buildings need consent, and conservation areas and Article 4 Directions can add restrictions.
Data sources
Checkatrade and the Energy Saving Trust for prices, the Planning Portal for the rules.
Show every source
- Checkatrade, Double glazing cost (updated May 2026): ballpark prices per double glazed window and for a 3 bed house, checked 5 October 2026.
- Energy Saving Trust, Energy efficient windows and doors (last updated 20 May 2026): £4,800 for a set of A-rated windows for a semi-detached house, £85 a year saved replacing single glazing, triple glazing around 20% dearer, a life of 20 to 35 years. Checked 5 October 2026.
- Planning Portal, Doors and windows: planning permission, checked 5 October 2026.