Double Glazing Cost Calculator UK
Get a realistic estimate for double glazing in the UK. Choose your window type, frame material, glazing spec, and quantity — and see an instant cost range before you contact any installer.
Double Glazing Cost Estimator
Select your options to get a UK cost estimate
Select the most common window type in your property
uPVC is cheapest · Timber is most expensive · Aluminium is mid-range
Low-E coated glass improves thermal performance significantly
Total number of windows to be replaced
Labour costs vary significantly by UK region
Cost Estimate
UK double glazing price range for your specification
Select your window type, frame material, and quantity — then click Estimate My Cost to see a UK price range.
Double Glazing Cost Factors
These are the key variables that push double glazing quotes up or down — understanding them helps you compare quotes accurately.
Frame Material
uPVC is the most cost-effective and lowest-maintenance option. Aluminium costs 20–40% more but is slimmer and more modern-looking. Composite blends materials for performance. Timber is the most expensive but the most characterful — essential for period properties and conservation areas.
Window Type & Style
Casement windows are the most affordable. Sash windows cost 20–40% more due to their mechanical complexity. Bay and bow windows are the most expensive, as they require custom manufacturing and more labour. Tilt-and-turn windows add a premium for their dual-function hardware.
Size of Windows
Larger windows use more glass and require stronger frames, increasing cost. A standard 1.2m × 1.2m casement costs considerably less than a floor-to-ceiling 2m × 1.8m panel. Unusual shapes — arched, circular, or triangular — also attract a significant premium.
Glazing Specification
Standard double glazed units are the cheapest. Low-E or A-rated units include a thermal coating and cost roughly 10–20% more, but offer significantly better energy performance. Triple glazing adds another 20–30% to the price and is most beneficial in colder or noisier locations.
Location in the UK
Labour rates vary significantly across the UK. London and the South East typically run 20–30% higher than the national average. The Midlands and North are usually at or below average. Scottish and Northern Irish installers often price competitively despite additional logistics.
Number of Windows
Ordering more windows at once typically reduces the per-unit cost, as installers can spread their mobilisation costs and manufacturers offer volume discounts. A full-house replacement often costs 10–15% less per window than replacing a single unit. Always get quotes for the full job.
Double Glazing Price Guide
Typical UK double glazing cost ranges per window by type and frame material. All prices include supply and installation. Scroll right on mobile.
| Window Type | uPVC (Low/High) | Aluminium | Composite | Timber | Tier |
|---|---|---|---|---|---|
| Fixed / Picture | £200 – £450 | £300 – £600 | £350 – £650 | £500 – £900 | Budget |
| Casement | £300 – £600 | £450 – £850 | £500 – £900 | £700 – £1,300 | Budget |
| Tilt & Turn | £400 – £750 | £550 – £950 | £600 – £1,050 | £800 – £1,500 | Mid |
| Sash / Sliding | £500 – £900 | £650 – £1,100 | £700 – £1,200 | £900 – £1,800 | Mid |
| Bay (3-pane) | £1,200 – £2,500 | £1,800 – £3,500 | £2,000 – £3,800 | £2,800 – £5,500 | Premium |
| Roof / Skylight | £700 – £1,400 | £900 – £1,800 | £1,000 – £2,000 | £1,200 – £2,500 | Premium |
Prices are indicative 2024 UK averages including VAT and standard installation. Costs vary by size, specification, region, and installer. Always obtain at least 3 quotes.
Double Glazing FAQ
Answers to the most common questions about double glazing costs and installation in the UK.
Double glazing costs in the UK typically range from £300–£600 per casement window in uPVC, rising to £700–£1,300 in timber. A full house replacement of 8–10 windows in standard uPVC typically costs between £3,500 and £7,000, while timber or composite can reach £8,000–£15,000. Prices vary significantly by region, window type, and installer.
uPVC offers the best upfront value — it is cheaper, thermally efficient, and virtually maintenance-free. Aluminium costs 30–50% more but is slimmer, stronger, and more contemporary-looking. It also lasts longer and suits larger window apertures. For modern homes or design-conscious buyers, aluminium’s durability often justifies the higher cost over a 25+ year lifespan.
Triple glazing offers better thermal and acoustic performance but typically adds 20–30% to the cost of double glazing. In the UK climate, the additional energy saving over good A-rated double glazing is modest — around £15–£40 per year in a typical home. It is most worthwhile for properties in exposed or cold locations, rooms that are difficult to heat, or home offices where noise reduction is important.
A typical window replacement takes 30–60 minutes per window once the installer is on site. A full house of 8–10 windows is usually completed in one or two days. More complex installations — bay windows, large panes, or period properties requiring careful removal — take longer. Lead times from order to installation are typically 4–8 weeks for bespoke manufactured units.
Replacing single glazing with modern A-rated double glazing can save approximately £110–£235 per year in an average semi-detached home. Replacing old (pre-2002) double glazing with modern units saves a more modest £20–£75 per year. Triple glazing saves a further £15–£40 over standard double glazing. Payback periods are typically 15–30 years purely on energy bills, though comfort and property value benefits add to the return.
In most cases in England, replacing windows with double glazing is permitted development and requires no planning permission. However, you may need consent if: your home is listed, you live in a conservation area where windows must match the original style, or you are making structural changes. Always check with your local planning authority if your property is in a designated area. In Scotland, Wales, and Northern Ireland, rules differ slightly.
FENSA (Fenestration Self-Assessment Scheme) is a government-authorised scheme allowing registered window installers to self-certify that their work complies with Building Regulations — primarily around thermal performance (Part L). Using a FENSA-registered installer means you receive a certificate of compliance, which is required when selling your property. Without it, you may need to apply retrospectively to your local council for a completion certificate.
Get at least three quotes from FENSA-registered installers — prices can vary by 40% or more for identical work. Avoid agreeing to a price on the same day as a sales visit. Consider timing your purchase outside peak spring and summer periods when demand is highest. Replacing all windows in one job rather than over time can reduce per-unit costs by 10–15%. Ask specifically about energy-efficiency grants or local authority schemes that may apply to your property.