Rates and data last verified 17 February 2026 by the ExpertSure editorial team. Sources are listed in the methodology below the calculator.
Double glazing a typical three-bedroom home with 8–10 windows costs about £3,750 in white uPVC on MyJobQuote’s national figures, with a single uPVC casement window costing £350–£550 fitted depending on size and glass specification. Aluminium frames push a full house to £4,700–£5,600 and softwood timber to £7,500–£12,000.
The Energy Saving Trust puts the saving from replacing single glazing with A-rated double glazing at about £85 a year for a gas-heated semi, so the investment takes decades to pay back on energy alone; comfort, noise reduction and condensation control are usually the stronger reasons to upgrade. This calculator provides a room-by-room cost estimate based on your window sizes, preferred frame material, and the number of openings in your property.
- A 3-bed home costs about £3,750 in white uPVC - for 8-10 windows fitted; aluminium runs £4,700-£5,600 and softwood timber £7,500-£12,000
- A single uPVC casement costs £350-£550 fitted - size, glass specification and opening style decide where you land in that range
- Replacing single glazing saves about £85 a year - the Energy Saving Trust figure for a gas-heated semi, so comfort and noise matter more than payback
- Double glazing carries 20% VAT - windows are excluded from the 0% energy-saving materials relief that covers insulation and heat pumps
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How to Use This Calculator
Select your property type (detached, semi-detached, terraced, flat) — this sets an estimated number of windows as a starting point.
Adjust the number and sizes of windows room by room, or use the quick estimate based on your property type.
Choose your frame material (UPVC, aluminium, or timber) and glass specification (standard or argon-filled) to see how these choices affect the total price.
Review the total estimated cost, per-window breakdown, and estimated annual energy savings compared to your current windows.
Use the quote comparison feature to see how prices from local installers compare against the national average for your specification.
What Affects Double Glazing Costs?
Eight factors affect double glazing costs: frame material (uPVC, aluminium, timber), glazing type (double vs triple), window style (casement, sash, tilt-turn), window size, number of windows, property access, regional labour rates, and installation complexity.
Understanding what drives double glazing costs helps you budget accurately and identify where you can save money without compromising quality. Here are the main cost factors.
Frame material is the single biggest cost variable. uPVC is the most affordable option at £250–£500 per window, offering excellent thermal performance and minimal maintenance. Aluminium frames cost £400–£700 per window and suit contemporary properties with larger glazed areas. Timber frames are the most expensive at £600–£1,200 per window but offer superior aesthetics for period homes and conservation areas.
Window style significantly impacts labour costs and material complexity. Standard casement windows are the cheapest to install. Sash windows require specialist fitting and precision hardware, adding 30–50% to the cost. Tilt-and-turn windows include more complex mechanisms, while bay and bow windows require custom fabrication and structural support.
Regional variation affects both material supply and labour rates. London and the South East typically see prices 15–25% higher than the national average. Scotland, Wales, and the North of England often have lower costs, though remote or island locations may face delivery surcharges.
Scaffolding and access can add £500–£1,500 to your total cost if you have upstairs windows or difficult access. Most ground-floor installations need no scaffolding. Multi-storey properties or those with restrictive access may require full scaffolding hire for 5–7 days.
How to Save Money on Double Glazing
Save on double glazing by ordering full-house installations (10–15% bulk discount), booking in winter off-peak months (Jan–Mar), comparing at least 3 quotes, avoiding high-pressure sales, and checking for local authority or energy efficiency grants.
Bulk discounts are substantial when you replace all windows at once rather than room-by-room. Most installers offer 10–15% off for whole-house jobs because it reduces their mobilisation costs and allows efficient scheduling. A project replacing 10 windows will typically cost 20–30% less per window than replacing just 2–3.
Seasonal timing affects pricing significantly. January to March is the quietest period for window installers, and many offer discounts of 10–15% to fill their schedule. Summer and early autumn are peak times when demand is high and prices firm. Booking in winter also means faster installation — often within 2–3 weeks rather than 6–8 weeks in peak season.
Avoid high-pressure sales tactics that create artificial urgency. “Today only” discounts of 40–50% usually mean the initial quote was inflated. Get written quotes from at least 3 FENSA-registered installers and compare like-for-like specifications. The best value typically comes from mid-sized local firms, not national chains or door-to-door sellers.
Energy efficiency grants can reduce your outlay. The ECO4 scheme offers fully-funded or subsidised double glazing for low-income households and those on certain benefits. In England, the council-run Warm Homes: Local Grant can fund double glazing for eligible low-income households, within cost caps averaging £16,600 per home for energy-performance measures. Check with your local authority, as not every council has signed up.
Energy Savings From New Windows
New A-rated double glazing saves about £85 a year on heating bills when it replaces single glazing in a gas-heated semi-detached house, according to the Energy Saving Trust. Triple glazing adds only a small extra saving but costs 30–40% more to install.
Replacing single-glazed windows with modern A-rated double glazing delivers measurable energy savings. According to Energy Saving Trust data, a gas-heated semi-detached house saves about £85 a year on heating bills after upgrading from single glazing to A-rated double glazing.
Triple glazing saves only a little more than modern double glazing, but typically costs 30–40% more to install. That premium takes decades to recover on energy savings, so it is hard to justify on cost alone; the main benefits are extra comfort and noise reduction.
New energy-efficient windows improve your property’s EPC rating, which affects resale value and rental demand. Replacing single glazing typically lifts a home by one or two EPC bands, while swapping older double glazing for new units makes much less difference to the rating.
Double Glazing Costs by House Type
Full-house prices below are for a typical 3-bed home with 8–10 windows, fitted, including VAT.
| Frame material | Per window (fitted) | 3-bed home, 8–10 windows |
|---|---|---|
| uPVC casement | £350–£600 | £4,000–£6,000 |
| Aluminium | £600–£850 | £7,000–£10,000 |
| Timber | Varies by species and style | £10,000–£16,000 |
For a smaller or larger home, scale by window count: each extra uPVC casement adds roughly £350–£550. Bay windows and non-standard sizes cost more. Use the calculator above for a room-by-room estimate.
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