Window replacement cost in 2026
Last reviewed: July 2026 · Prices are fitted (supply + installation), incl. VAT
Replacing a window in the UK costs £450–£750 per window fitted in uPVC, and a typical whole house lands between £2,300 and £6,750. Those are wide bands because the price moves with how many windows you replace, the frame material, and where you live — our estimate tool narrows it to your own home in under a minute, with no contact details needed.
Replacement cost per window, by material
| Frame material | Fitted price per window | Best for |
|---|---|---|
| uPVC | £450 – £750 | Value and low maintenance — the UK default |
| Aluminium | £650 – £1,100 | Slim frames, big panes, modern homes |
| Timber | £850 – £1,500 | Period properties, conservation areas |
Bands assume a standard casement around 1200×1200mm with A-rated double glazing, like-for-like replacement, normal access. Sash windows and bays cost more — often 50–100% more for sliding sash designs.
Whole-house replacement examples
| Home | uPVC (fitted) | Aluminium (fitted) |
|---|---|---|
| Flat (3–4 windows) | £1,650 – £2,750 | £2,400 – £4,050 |
| 2-bed terrace (5–6 windows) | £2,300 – £3,850 | £3,350 – £5,650 |
| 3-bed semi (7–9 windows) | £2,700 – £4,500 | £3,900 – £6,600 |
| 4-bed detached (10–12 windows) | £4,050 – £6,750 | £5,850 – £9,900 |
What a proper replacement quote includes
- Survey and measuring — every opening measured, not scaled off a photo.
- Removal and disposal — the old frames taken out and taken away.
- Fitting and making good — sealed, trimmed and plaster tidied around the reveals.
- Certification — a FENSA or CERTASS certificate lodged for the work (you will need it when you sell).
- A written guarantee — typically 10 years on frames and sealed units.
If a quote undercuts everyone else by a distance, the gap is usually one of these items quietly missing.
Are you sure you need full replacement?
The single most expensive mistake in this market is replacing windows whose frames are fine. If your glass has misted but the frames are sound, you likely only need the sealed units swapped at £75–£200 per window — see our misted double glazing guide. For handles, hinges, locks and draughts, the repair guide covers what each fix costs. The working rule: if repairs quoted come to more than half the cost of replacement, replace; otherwise repair.
Like-for-like or upgrade?
- Like-for-like uPVC is the cheapest route and what the bands above assume.
- Upgrading the glass to triple glazing adds roughly 15–25% (worth it?).
- Changing style — casement to sash, or adding bays — is where budgets jump; the joinery is genuinely more expensive.
- Colour and finish — woodgrain foils and non-white colours add 10–20% on uPVC.
Frequently asked questions
How much does it cost to replace one window?
A single uPVC casement window typically costs £450–£750 fitted, including removal and disposal of the old frame. Aluminium runs £650–£1,100 and timber £850–£1,500. One-off jobs sit toward the top of each band because the installer cannot spread survey and travel costs across multiple windows.
Does window replacement include removing the old windows?
A proper fitted quote should include removal and disposal of your old frames, fitting the new windows, sealing and making good around the reveals, and FENSA or CERTASS certification. If a quote looks unusually cheap, check whether disposal and making good are actually included.
Do I need Building Regulations approval to replace windows?
The work must comply with Approved Document L (U-value 1.4 W/m²K or better in England and Wales), but you do not need to apply to the council yourself — FENSA and CERTASS registered installers self-certify the work and lodge the certificate for you. Keep it: solicitors ask for it when you sell.
Is it worth replacing windows before selling a house?
Sometimes. New windows rarely return their full cost in added value, but visibly failed windows — misted glass, rotten frames — suppress offers and give buyers a negotiating stick. If the frames are sound and only the glass has failed, replacing the sealed units for £75–£200 each is usually the smarter pre-sale spend.
Sources: price bands compiled July 2026 from published UK installer price guides (Checkatrade, Which?, FMB cost guides) and cross-checked against regional quote data. Regulations: Approved Document L. Installer certification: FENSA.