The short answer
A single double glazed uPVC window typically costs £400–£900 supplied and fitted in 2026; aluminium runs £550–£1,300 and timber £800–£1,800 or more. The per-window price usually falls when you order several at once, because survey, setup and travel costs are spread across the job. Size, opening style and glass specification are the main variables. These are typical illustrations, not quotes — see the main cost guide for whole-house figures.
Quoting double glazing “per window” is a useful way to compare, but it can mislead if you don’t account for how installers actually price a job. This guide explains the realistic per-window ranges for each frame material in 2026, how size and style change the figure, and why the headline single-window price is almost always higher than the per-window cost of a whole-house order.
Cost per window at a glance
- uPVC casement £400–£900
- Aluminium casement £550–£1,300
- Timber casement £800–£1,800+
- Small fixed / top-hung From £350–£450
- Large or sash-style £700–£1,500+
- Per-window drop on a big order 10–25% lower
Per-window prices by frame material
Frame material is the biggest single driver of the per-window price. uPVC is the most affordable and the default for most homes, typically £400–£900 for a standard casement supplied and fitted. Aluminium — slimmer, stronger and favoured for modern looks — usually costs 30–50% more, so £550–£1,300 per window. Timber, often required in conservation areas, is the most expensive at £800–£1,800 or more, partly for the material and partly because it needs periodic maintenance. The glass itself is broadly similar across all three; the premium is in the frame. See the dedicated material cost comparison for the detail.
| Window style (uPVC) | Typical size | Supply & fit |
|---|---|---|
| Small fixed / top-hung | 500 × 500 mm | £350–£500 |
| Standard casement | 1000 × 1000 mm | £450–£750 |
| Large casement | 1200 × 1200 mm | £600–£950 |
| Sash-style (uPVC) | 1000 × 1400 mm | £700–£1,200 |
How size and style change the price
Bigger windows use more frame and more glass, so a large casement costs more than a small one of the same material. Opening style matters too: a fixed pane is cheapest, a single top-hung opener a little more, and multi-opener or sash-style windows the most, because there is more hardware and more labour. Decorative glass, astragal bars, colour finishes and integral blinds all add to the figure. If noise or security is a concern, acoustic or laminated glass adds to the glass cost — see double glazing for noise reduction.
Why ordering more lowers the per-window cost
The single biggest reason a quoted “per window” price varies is order size. An installer’s survey, setup, scaffolding, travel and certification costs are largely fixed regardless of how many windows they fit. Spread across one window, those costs sit heavily on the per-unit price; spread across ten, they almost disappear. As a rule of thumb, the per-window cost on a whole-house order is typically 10–25% lower than the price of replacing a single window in isolation. That is why a single replacement can feel expensive and a full-house quote feels better value per window. For whole-house totals by property size, see cost to replace all the windows in a house.
What the per-window price should include
A proper per-window price should cover the frame and sealed unit, removal and disposal of the old window, fitting, making good around the reveal, and the FENSA or CERTASS certificate. Trickle vents are now required on most replacement windows under Building Regulations Part F, so check they are included rather than added later. If a price looks unusually low, confirm what is in it: disposal, making good and certification are sometimes left out of a headline figure. This is general information; the actual cost depends on your property, the windows you choose and your installer.
Compare double glazing quotes
Per-window prices vary with material, size, style and order size. Use our service to compare quotes from FENSA or CERTASS registered installers in your area.
Frequently asked questions
How much is one double glazed window fitted?
A standard uPVC casement is typically £400–£900 supplied and fitted in 2026. Aluminium runs £550–£1,300 and timber £800–£1,800 or more. A single window in isolation usually costs more per unit than the same window as part of a whole-house order.
Is it cheaper per window to do the whole house at once?
Usually, yes. Fixed costs like survey, setup, travel and certification are spread across more windows, so the per-window cost on a whole-house order is typically 10–25% lower than replacing a single window on its own.
Why are some windows so much more expensive?
Frame material is the main reason — aluminium and timber cost more than uPVC. Size, opening style, decorative glass, colour finishes and a higher energy rating or acoustic glass also add to the per-window figure.
Should the price include trickle vents?
Most replacement windows now need trickle vents under Building Regulations Part F to maintain background ventilation. Check they are included in the per-window price rather than added as an extra later.
Sources & further reading
- FENSA — guidance on replacement windows and finding registered installers
- Glass and Glazing Federation (GGF) — consumer guidance on window costs and specifications
- Energy Saving Trust — double glazing and typical installation costs
- GOV.UK / Building Regulations Approved Document F — ventilation requirements 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.