🧮 Interactive Calculator · 2026 UK Pricing · No Sign-up

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 FENSA-registered installer rates. No email needed.

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Real 2026 UK pricing

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Supply + fit, FENSA

Free quotes, no obligation

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<a href="https://www.bestbuilders.co.uk/costs/double-glazing-cost-calculator"><img src="https://www.bestbuilders.co.uk/img/infographics/double-glazing-cost-calculator.svg" alt="Double glazing costs in the UK (2026) - BestBuilders" width="720" style="max-width:100%;height:auto"></a><p>Source: <a href="https://www.bestbuilders.co.uk/costs/double-glazing-cost-calculator">BestBuilders</a></p>

Pick your frame material, enter how many windows you need and choose your region for an instant 2026 fitted-price estimate.

Methodology

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 FENSA/CERTASS installer rates.

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.

Frequently Asked Questions

How much does double glazing cost in 2026?

Expect around £450–£900 per uPVC window fitted in 2026. A whole-house uPVC job of 8–10 windows is typically £4,500–£8,500, aluminium runs £900–£1,400 per window and heritage sash £1,000–£1,800. London and the South East are 10–25% higher.

Does the price include fitting?

Yes — these are supply-and-fit estimates per window, including removal of the old units and installation. Bay windows, very large units and structural openings cost more.

Why is aluminium and timber more expensive than uPVC?

Aluminium offers slimmer, stronger frames and timber suits period and listed homes, so both cost more than standard uPVC. Heritage sash windows are the priciest because of the joinery and conservation detailing involved.

Do I need Building Regulations approval?

Replacement windows must meet Building Regulations for energy efficiency. A FENSA or CERTASS registered installer self-certifies the work, so you do not need a separate building control application.

How long does it take to fit a house of windows?

A typical 8–10 window installation is usually completed in one to three days, depending on access, frame type and any made-good plastering or decorating needed afterwards.

How accurate is this double glazing cost calculator?

It gives a realistic guide from 2026 UK prices for your window count, frame material and style, not a fixed quote. Actual cost depends on exact sizes, opening configuration, glass spec, access height and whether old frames need careful removal. An installer measures every opening and confirms the price after a home survey.

What does the double glazing estimate include and exclude?

The figure covers the windows, standard clear or low-E glass, fitting, removal and disposal of old units and FENSA or Building Regs certification with VAT. It excludes bay window structural work, coloured or acoustic glass upgrades, replastering or making good internally, scaffolding for upper floors and any lintel repairs. A survey confirms the extras.

Why might a real window quote differ from the calculator?

The calculator assumes standard-sized openings on an easily accessed house. After measuring, an installer may adjust for large or bay windows, non-standard shapes, rotten timber or lintels found on removal, upper-floor access needing scaffolding, and conservation-area or listed-building rules. London and heritage jobs cost more, so use the estimate as a starting point.