How much does triple glazing cost in the UK?
Triple glazing costs £800 on average in the UK. Most jobs fall between £450 and £1,600 per window supplied and fitted. Window size or type: Small casement £450 to £700; Standard window £650 to £1,000; Large £1,000 to £1,600. Prices reviewed July 2026.
Triple glazing usually costs between £450 and £1,600 per window supplied and fitted in the UK, with most homeowners paying around £800 per window. The price depends mainly on the window size, the frame material and how many windows you replace at once.
Triple glazing cost calculator
Use the calculator to price your triple glazing in 2026. Adjust the options and area for a UK cost range. Nothing is sent anywhere.
To price the whole job, use the double glazing cost calculator.
Triple glazing cost breakdown
The cheapest option is Small casement, up to 60x90cm at £450 to £700, and the dearest is Large, bay or premium frame at £1,000 to £1,600. Typical is £800 per window supplied and fitted.
| Window size or type | Typical UK cost |
|---|---|
| Small casement, up to 60x90cm | £450 to £700 |
| Standard window | £650 to £1,000 |
| Large, bay or premium frame | £1,000 to £1,600 |
What's included in the price?
Typical triple glazing prices include:
- A survey and accurate measurements of each opening
- Three panes of glass with two insulating gas-filled gaps
- The new frames in your chosen material and colour
- Removal and disposal of the old windows
- Fitting, sealing and making good around each frame
- A FENSA or CERTASS certificate for building control
What changes the price?
The things that move triple glazing prices most:
The size and number of windows
The frame material (uPVC, aluminium or timber)
The window style, such as casement, sash or bay
The glass spec and energy rating
Access and whether scaffolding is needed
Your region
These are why two quotes for the same job can differ, and the only way to know your price is to get prices from local firms (through Bark; we may earn a fee, at no extra cost to you).
How the price is built up
Most of the cost is the sealed triple-glazed unit and the frame, both made to measure for each opening. The rest covers the survey, taking out the old window, fitting and sealing the new one, and the building control certificate. Larger openings, bay windows and aluminium or timber frames push the price up. The glass units and frames make up most of the price; fitting is usually a day rate for a two-person team. On a typical window the materials are the larger share of the cost.
Ways to keep the cost down
- Replace all the windows in one go rather than one or two at a time
- Get three quotes from local FENSA-registered fitters, not just national brands
- Stick to standard casement styles and colours
- Ask whether double glazing with a warm-edge spacer would meet your needs for less
Does where you live change the cost?
In London, triple glazing typically costs around £960 per window supplied and fitted, about 20% above the UK average of £800. In the North, Scotland and Wales the guide figure is nearer £780.
| Region | From | Typical | Up to |
|---|---|---|---|
| Midlands / East (UK average) | £450 | £800 | £1,600 |
| London | £540 | £960 | £1,900 |
| South East / South West | £470 | £840 | £1,700 |
| North / Scotland / Wales | £440 | £780 | £1,600 |
Guide prices per window supplied and fitted, scaled with the same regional multipliers as the calculator. Not quotes.
Triple glazing cost in major UK cities
| City | From | Typical | Up to |
|---|---|---|---|
| Belfast | £430 | £760 | £1,500 |
| Birmingham | £450 | £800 | £1,600 |
| Bristol | £470 | £840 | £1,700 |
| Cardiff | £440 | £780 | £1,600 |
| Edinburgh | £440 | £780 | £1,600 |
| Glasgow | £440 | £780 | £1,600 |
| Leeds | £440 | £780 | £1,600 |
| Liverpool | £440 | £780 | £1,600 |
| London | £540 | £960 | £1,900 |
| Manchester | £440 | £780 | £1,600 |
| Newcastle | £440 | £780 | £1,600 |
| Sheffield | £440 | £780 | £1,600 |
City guide estimates, scaled by local labour costs. Indicative averages for triple glazing, not quotes.
Installers in London and the South East charge the most; the North, Wales, Scotland and Northern Ireland are typically a little cheaper for the same window.
Compare this with a real quote
The figures above are guide prices. Two or three quotes for your triple glazing tell you what it costs where you live.
Free and no obligation. You answer a few questions on Bark, local pros get in touch, and you decide who, if anyone, to hire. We may earn a fee, at no extra cost to you.Common questions
How much does triple glazing cost in 2026?
Around £450 to £1,600 per window supplied and fitted, with most people paying about £800. A typical three-bed house of 8 to 10 windows comes to roughly £6,000 to £10,000.
How much more does triple glazing cost than double glazing?
Expect to pay roughly 20 to 40 percent more than double glazing for the same window, so about £150 to £350 extra on a standard casement. The gap is wider on large or bespoke windows.
Is triple glazing worth it over double glazing?
For most homes good double glazing already cuts heat loss well. Triple glazing helps most in cold or exposed spots, in new builds aiming for low energy bills, or where you want extra noise reduction. On an older house the fuel saving alone rarely pays back the extra cost, so weigh comfort and quiet, not just bills.
Can I fit triple glazing myself?
Fitting replacement windows is not a DIY job for most people. The work has to comply with building regulations, and a poor fit causes draughts and leaks. Unless your installer is registered with a competent person scheme for replacement windows, such as FENSA or CERTASS, you have to notify building control and pay for an inspection yourself.
How long does triple glazing take to install?
A single window is swapped in a few hours. A full house of 8 to 10 windows takes 2 to 3 days on site, after a 3 to 4 week wait for the made-to-measure frames.
How long does triple glazing last?
Around 20 to 30 years for the sealed units, with uPVC frames commonly put at 20 to 35, so as with double glazing it is the glass rather than the frame that decides when you replace. Most sealed-unit guarantees run to about 10 years, which is a good deal shorter than the expected life and worth reading rather than assuming. The first sign is misting or condensation between the panes, meaning that unit has lost its seal, and the gas fill escaping costs you performance for a while before any misting shows. One point specific to triple: you replace the failed unit rather than the whole window, but a triple unit is heavier and dearer to replace than a double, so factor that in when weighing £450 to £1,600 per window against double glazing. Frames outlasting the glass is the same pattern as double glazing, and the reason a misted window is usually a unit replacement and not a new window.
What is a cheaper alternative to triple glazing?
Secondary glazing, an extra pane fitted inside your existing window, costs far less and cuts draughts and noise, though it insulates less than a full triple-glazed unit. Double glazing with a warm-edge spacer is another middle option.
Do building regulations require triple glazing?
No. In England, Approved Document L sets the standard for a replacement window in an existing home as a U-value of no more than 1.4 W/m²K, or a Window Energy Rating of band B or better. That is a performance figure, not a number of panes, so a double-glazed window that reaches it complies as fully as a triple-glazed one. Ask for the certified U-value or energy rating on the quote. The 2026 edition of Approved Document L, which takes effect on 24 March 2027, keeps the same limit.
Will new triple-glazed windows need trickle vents?
Usually, yes. In England, Approved Document F says that if your old windows have background ventilators the new ones should too, no smaller and controllable; if they have none, the work must leave the home's ventilation no worse, for example with at least 8,000mm² of vent in each habitable room and kitchen and 4,000mm² in a bathroom. Government guidance says a signed disclaimer from the homeowner is not a way round this. If you are buying triple glazing to cut road noise, it recommends noise-attenuating vents, and a vent through the wall can also comply.
Check they are registered before they start
Replacement windows and doors have to comply with the building regulations. A fitter in an authorised scheme certifies their own work and gives you the certificate; without one you need a building control application. Checking takes about a minute and it is free.
- Find a FENSA approved installer FENSA · FENSA is one of the authorised schemes for replacement windows and doors, not the only one, so a fitter registered with Certass or another scheme can certify the work just as well
Official guidance and sources
The rules and schemes referenced on this page come from these official UK sources. The price figures are Costwise's own; see how we price.
- Doors and windows: building regulations Planning Portal · Replacement windows and doors must meet the building regulations, either self-certified by an installer in a competent person scheme or approved by building control.
- Competent person schemes: current schemes and how they are authorised GOV.UK · Six schemes are authorised for replacement windows and doors in existing homes in England: Assure, Blue Flame Certification, CERTASS, Certsure, FENSA and NAPIT.
- Approved Document L, volume 1: dwellings GOV.UK · The standard for a replacement window in an existing home: a U-value no worse than 1.4 W/m²K, or a Window Energy Rating of band B or better.
- Approved Document F, volume 1: dwellings GOV.UK · Replacement windows must not leave a home's ventilation worse: existing trickle vents are replaced like for like, and where there were none, vents of set sizes per room are the usual answer.
Cite this data
These figures are free to use in articles, reports and research under a CC BY 4.0 licence. All we ask is a credit to Costwise, and online a link. Where your style allows, please make "Costwise" the linked word so readers can check the figure for their own region.
Costwise (2026): Triple glazing typically costs £800 per window supplied and fitted in the UK, ranging from £450 to £1,600 per window supplied and fitted. Reviewed July 2026. costwiseuk.co.ukSource: Costwise (costwiseuk.co.uk)Costwise (2026). Triple glazing cost. Costwise UK cost data, version 2026-10-12. https://costwiseuk.co.uk/triple-glazing-cost/2026-10-12 (158 jobs)Dataset DOI: 10.5281/zenodo.21159943 · also on Kaggle, Hugging Face and Figshare. Method: how we price. Downloadable CSV.
These are independent guide prices based on typical UK jobs in 2026. Your actual cost depends on your property, spec, access and where you live. Always get at least three written quotes before committing.