The short answer
Replacing all the windows in a typical UK house costs roughly £4,000–£9,000 in uPVC for an 8–10 window home in 2026. A small two-bed flat might be £2,500–£5,000; a large four or five-bed house £9,000–£15,000 or more. Aluminium adds around 30–50% and timber more again. Window count, sizes, bay windows and access are the main variables. These are typical illustrations, not quotes — see the main cost guide for the breakdown.
Replacing every window at once is the most cost-effective way to buy double glazing, because the installer’s fixed costs are spread across the whole job. This guide gives realistic 2026 whole-house ranges by property size, explains what moves the figure, and shows why a per-window price drops as the order grows. All figures are typical illustrations rather than quotes.
Whole-house cost at a glance (uPVC)
- 2-bed flat (4–6 windows) £2,500–£5,000
- 2–3-bed terrace (6–8 windows) £3,500–£7,000
- 3-bed semi (8–10 windows) £4,000–£9,000
- 4-bed detached (10–14 windows) £7,000–£13,000
- 5-bed+ (14–20 windows) £9,000–£15,000+
- Aluminium uplift +30–50%
Whole-house cost by property size
The biggest factor in a whole-house figure is simply how many windows you have and how big they are. A small flat with four to six modest windows in uPVC might come to £2,500–£5,000; a three-bedroom semi with eight to ten windows typically lands at £4,000–£9,000; and a large detached house with bays and a dozen-plus windows can reach £9,000–£15,000 or more. Within each band, the spread reflects window sizes, opening styles, glass specification and whether any bay or feature windows are involved.
| Property | Typical windows | uPVC supply & fit |
|---|---|---|
| 2-bed flat | 4–6 | £2,500–£5,000 |
| 2–3-bed terrace | 6–8 | £3,500–£7,000 |
| 3-bed semi | 8–10 | £4,000–£9,000 |
| 4-bed detached | 10–14 | £7,000–£13,000 |
| 5-bed+ detached | 14–20 | £9,000–£15,000+ |
What changes the whole-house figure
Beyond window count, several things move the total:
- Frame material — aluminium typically adds 30–50% over uPVC, and timber more again. See the material cost comparison.
- Bay and bow windows — each one costs £900–£2,500 fitted, well above a flat window. See bay window cost.
- Glass specification — triple glazing, acoustic glass or a higher energy rating add across every window.
- Access — upper floors needing scaffolding, or awkward openings, add labour and equipment cost.
- Doors — many whole-house jobs include patio, French or front doors, which are priced separately and add to the total.
Phasing the work versus doing it all at once
If a whole-house figure is beyond your budget, you can phase the work — for example, the front elevation first, then the rest later. The trade-off is that you typically pay a higher per-window rate each time, because the installer’s fixed costs recur on each visit. Many installers also offer finance to spread the cost of a single whole-house job over 12–120 months. Either way, the work is notifiable under Building Regulations, so use a FENSA or CERTASS registered installer who will issue a certificate covering every window fitted. This is general information; your actual cost depends on your property and chosen installer.
Compare double glazing quotes
Whole-house prices vary widely with window count, material and access. Use our service to compare quotes from FENSA or CERTASS registered installers in your area.
Frequently asked questions
How much to replace all windows in a 3-bed house?
A typical three-bedroom house with 8–10 windows costs roughly £4,000–£9,000 in uPVC, supplied and fitted. Aluminium or timber frames, bay windows and upper-floor access push this higher. These are typical illustrations, not quotes.
Is it cheaper to replace all windows at once?
Usually, yes. Doing the whole house in one job spreads the installer’s fixed costs across every window, so the per-window cost is typically 10–25% lower than replacing windows one at a time over several visits.
How long does it take to replace all the windows in a house?
A typical team fits several windows a day, so most whole-house jobs take one to three days. See our guide on how long it takes to fit double glazing.
Can I pay for new windows in instalments?
Many installers offer finance to spread the cost over 12–120 months. Always check the total amount payable and the interest rate, and compare it against paying upfront or phasing the work.
Sources & further reading
- FENSA — guidance on replacement windows and Building Regulations compliance
- Glass and Glazing Federation (GGF) — consumer guidance on whole-house window replacement
- Energy Saving Trust — double glazing, energy efficiency and typical costs
- GOV.UK / Building Regulations Approved Document L — thermal standards for replacement windows
This is general information, not advice for your specific property or installation. Costs vary with your home, the windows you choose and your chosen installer. Replacement windows should be fitted by a FENSA or CERTASS registered window installer. We are an independent information and introduction service, not an installer.