Cost guide

How much does double glazing cost? UK prices for 2026

Independent guide · updated October 2026

In 2026, a replacement uPVC casement window typically costs around £500–£1,200 supplied and fitted, and double glazing a whole 3-bedroom home usually runs about £8,000–£15,000. What you pay depends on how many windows you have, the frame material, the glass specification and where you live. The figures below are guide prices — always compare three quotes from local installers on a like-for-like basis.

Double glazing prices at a glance

Window type (supplied & fitted)	Typical price each
uPVC casement (standard)	£500–£1,200
Tilt-and-turn / sliding	£600–£1,400
Sash window	£800–£1,500+
Bay or bow window	£1,500–£4,000+

Whole home (uPVC, fitted)	Typical total
Terraced house (~5–6 windows)	£4,000–£8,000
3-bed semi (~8–12 windows)	£8,000–£15,000
Larger / detached home	£12,000–£20,000+

Guide prices for 2026, uPVC frames with A-rated double glazing. Aluminium and timber cost more (see below), as do triple glazing and bespoke shapes or colours.

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What affects the price of double glazing?

Six things move the price most: the number and size of windows; the frame material (uPVC, aluminium or timber); the glass specification (energy rating, and any acoustic, toughened or decorative glass); access and whether scaffolding is needed; making good (plastering and finishing around the new frames); and where you live — London and the South East typically sit at the higher end. Bespoke colours, shaped heads and heritage details all add cost too.

uPVC vs aluminium vs timber

uPVC is the most affordable option and the most common choice for replacement windows — low-maintenance and thermally efficient. Aluminium typically costs around 20–30% more; its slim frames suit large windows, sliding doors and bi-folds. Timber generally costs 50% or more above uPVC and is often chosen for period properties and conservation areas where uPVC may not be permitted. There is no single "best" material — it depends on your property, your budget and the look you want.

Double vs triple glazing

Double glazing is the standard for UK homes and is what these prices assume. Triple glazing usually costs more — often in the region of 15–30% extra per window — and can help in very cold or noisy locations. For most homes, though, a good A-rated double-glazed unit already performs well, so the extra outlay has diminishing returns. Ask any installer what U-value you would actually be getting before paying a premium.

Door prices

Door type (supplied & fitted)	Typical price
Composite or uPVC front door	£700–£1,500
French doors	£1,000–£2,000
Sliding patio doors	£1,200–£2,500
Bi-fold doors (uPVC)	£2,000–£4,500
Bi-fold doors (aluminium)	£3,000–£7,500

Bi-fold prices rise with the opening width and the number of panels; aluminium costs more than uPVC but gives slimmer sightlines.

Building Regulations and FENSA — what it means for cost

Replacement windows and doors must meet the Building Regulations: in England that means a U-value of 1.4 W/m²K or a Window Energy Rating of at least band B, and no worse than what they replace. Using a FENSA- or CERTASS-registered installer means the work is self-certified and registered for you, and you get a compliance certificate — which you will need when you sell. A registered installer includes this in the price, so it is not usually an extra; be cautious of a quote that is unusually cheap because the firm is not registered.

How to get a fair price

Prices for the very same job vary widely between firms, so comparing quotes is the biggest saving you can make. Get at least three written quotes on a like-for-like specification — same frame material, glass rating and guarantee length — and check each firm's accreditations. Avoid high-pressure "today only" discounts and large upfront deposits, and make sure the quote states whether scaffolding and making-good are included. You can compare window & door specialists, browse installers by area, or jump straight to the area & service finder.

Double glazing cost — frequently asked questions

How much does one double glazed window cost in the UK?

As a 2026 guide, a standard replacement uPVC casement window costs roughly £500–£1,200 supplied and fitted, with most mid-range windows landing around £700–£1,000. Sash, bay and bow windows cost more because they are larger and more complex. The exact price depends on the size, the frame material and the glass specification.

How much does it cost to double glaze a whole house?

For a typical 3-bedroom home with 8–12 windows, whole-house double glazing usually costs about £8,000–£15,000 fitted in uPVC. A smaller terraced home might be £4,000–£8,000, while larger homes, premium frames (aluminium or timber) or triple glazing push the figure higher. Getting three like-for-like quotes is the best way to gauge a fair price.

Is uPVC, aluminium or timber cheapest?

uPVC is the most affordable and dominates the UK replacement market. Aluminium typically costs around 20–30% more than uPVC (favoured for large, slim-framed windows and bi-fold doors), and timber around 50% or more above uPVC (often chosen for period and conservation-area homes).

Is triple glazing worth the extra cost?

Triple glazing usually costs more than double glazing — often in the region of 15–30% more per window. It can help in very cold or noisy locations, but for most UK homes a good A-rated double-glazed unit already performs well, so the extra outlay has diminishing returns. Ask your installer what U-value you would actually gain.

Do new windows have to meet Building Regulations?

Yes. Replacement windows in England must meet the Building Regulations — a U-value of 1.4 W/m²K or a Window Energy Rating of at least band B, and no worse than the windows they replace. A FENSA- or CERTASS-registered installer self-certifies the work and gives you a compliance certificate, which is included in a registered installer's price.

How can I get double glazing cheaper without cutting corners?

Get at least three written quotes on a like-for-like specification (same frame material, glass rating and guarantee), avoid high-pressure "today only" discounts and large upfront deposits, and check each firm's accreditations. Prices for the same job vary widely between installers, so comparing local firms is the single biggest saving.

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Prices are 2026 UK guide ranges triangulated from public cost data and industry experience; your quote will vary with your property and specification. This guide is general information, not a quotation.