Double Glazing Cost Calculator UK
Estimate the 2026 cost of new double glazing in 30 seconds — by frame material, number of windows and region. Realistic supply-and-fit figures from real installer rates. No email needed.
Estimate Your Double Glazing Cost in 30 Seconds
Pick your frame material, enter how many windows you need and choose your region for an instant 2026 fitted-price estimate.
How This Calculator Works
We multiply the per-window supply-and-fit rate for your chosen frame by the number of windows, then apply a regional multiplier, using real 2026 installer rates. In practice the biggest swings come from the glass and frame spec rather than the headline per-window rate: triple glazing, acoustic or toughened safety glass, astragal bars, coloured or foiled finishes and non-standard shapes all push the figure up, while a straight like-for-like uPVC casement swap on the ground floor sits at the lower end. For a full breakdown of what moves the price, read our double glazing cost guide; if you are matching original box sash windows, the sash window cost guide covers heritage joinery, and you can compare vetted local fitters through our double glazing quotes page.
Per-Window Rates (supply + fit)
- uPVC casement — ~£620/window (£450–£900)
- uPVC sash — ~£820/window
- Aluminium — ~£1,150/window (£900–£1,400)
- Timber / heritage — ~£1,400/window (£1,000–£1,800)
A whole-house uPVC job of 8–10 windows is typically £4,500–£8,500 in 2026.
Regional Multipliers
- London 1.25× · South East 1.12×
- Midlands & East 1.00× (baseline)
- South West & Wales 0.95×
- North & Scotland 0.90×
A FENSA or CERTASS registered installer self-certifies to Building Regulations. A real quote follows a survey.
Typical Double Glazing Costs (2026)
Supply & fit per window and whole-house (8–10 windows), Midlands baseline.
| Frame type | Per window | Whole house (8–10) |
|---|---|---|
| uPVC casement | £450–£900 | £3,600–£9,000 |
| uPVC sash | ~£820 | £6,560–£8,200 |
| Aluminium | £900–£1,400 | £7,200–£14,000 |
| Timber / heritage | £1,000–£1,800 | £8,000–£18,000 |
These figures power the calculator above — enter your own spec for a tailored estimate. For the full breakdown, read our complete cost guide.
What drives the price of double glazing
The headline per-window rate is only a starting point; the spec is what moves a whole-house quote by thousands. Frame material sets the floor — standard uPVC casements are the cheapest, uPVC sash costs more for the mechanism, and aluminium and timber sit higher again for the slimmer sightlines or the joinery. On top of that sits the glass: stepping up from standard low-E to acoustic, toughened safety or triple-glazed units, or adding astragal bars, a coloured or woodgrain foil and non-standard shapes, all add cost per opening. A run of plain casements on the ground floor is quick; bay windows, arched heads and anything above the ground floor that needs scaffolding are not.
Window count and access then scale it. Ten openings cost roughly ten times one, but upper floors, awkward approaches and careful removal of original frames add labour, and London and the South East run above the Midlands baseline. A reputable installer is registered with FENSA or CERTASS and self-certifies the work to Building Regulations, so you avoid a separate building-control application. For a full breakdown of every frame and glass option see our double glazing cost guide; if you are matching original box sash windows in a period home, the sash window cost guide covers the heritage detailing, and you can line up quotes from vetted local fitters through our double glazing quotes hub.
Frequently Asked Questions
How much does double glazing cost in 2026?
Does the price include fitting?
Why is aluminium and timber more expensive than uPVC?
Do I need Building Regulations approval?
How long does it take to fit a house of windows?
How accurate is this double glazing cost calculator?
What does the double glazing estimate include and exclude?
Why might a real window quote differ from the calculator?
Is triple glazing worth the extra cost?
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