Double Glazing Cost Calculator
Check what new windows should cost, then get free quotes from local installers.
Your Estimate
£4,000 – £10,000- Supply only, you arrange fitting−£3,450
- Upgrade to triple glazing+£1,200
- Switch to aluminium frames+£2,450
- Switch to timber frames+£6,300
Now find out what yours actually costs
Installers covering your postcode will quote for your real windows, so you have something to check the benchmark against.
Get quotes for my 10 windowsPrices are estimates based on UK market averages for 2026. Actual costs vary by supplier, location and property. Always get 3 quotes before committing.
Disclaimer: This calculator gives a guide price, not a quote. The figures are 2026 UK market averages and assume standard-sized openings on a property with normal access. Your real cost depends on exact sizes, opening configuration, glass spec, access height and what is found when the old frames come out, all of which an installer confirms at survey. Replacement windows must meet Building Regulations, and a FENSA or CERTASS registered installer self-certifies that work. You use these estimates at your own risk. Our figures and sources are set out in the methodology.
The estimate above is built from 2026 UK installer pricing, where a fitted uPVC casement runs £400 to £1,000 a window and a three-bed house lands between £4,000 and £10,000 for the full set. If you want the reasoning behind those bands rather than one number, how much double glazing costs in 2026 breaks the price down by style, material, house size and region. To price a single material properly, the uPVC window price calculator narrows the same maths to the frames most UK homes actually buy. Where you live moves the figure too, and double glazing cost in London shows the widest gap from the national average of any city we price. And if you are still deciding whether to replace at all rather than what to spend, is double glazing worth it in 2026 weighs the saving against the outlay. And where the windows coming out are already double glazed, double glazed window replacement sets out what changes when the job is an upgrade rather than a first fit.
From Estimate to Installer Quotes
Four steps, and the first two take about a minute
- Step 1
Describe Your Windows
Property type, how many windows, the style, the frame material and double or triple glazing.
- Step 2
Get Your Estimate
A 2026 price range for the job, the average cost per window and what you would save on energy each year.
- Step 3
Request Free Quotes
We pass your enquiry to Leads 2 Trade, who call to confirm what you need and then arrange quotes from up to four local installers.
- Step 4
Compare and Decide
Check every quote you are given against the estimate above, so you can see which ones are fair before you sign anything.
What Affects the Cost?
Double glazing prices vary widely. Here are the biggest factors that move your final figure up or down:
- Number of windows the single biggest driver of total cost.
- Window style sash and bay windows cost far more than standard casements.
- Frame material uPVC is cheapest, aluminium mid-range, timber the most expensive.
- Double vs triple glazing triple adds roughly 10 to 20% to the price.
- Installation complexity listed buildings, upper floors and scaffolding add cost.
- Location London and the South East are typically 15 to 25% more expensive.
Frame Material, Relative Cost
Window Style, Relative Cost
Glazing, Relative Cost
Cost per window against the cheapest option in each group, from our 2026 price table. Window styles are compared in uPVC, so the frame material does not skew the shape.
2026 Double Glazing Price Guide
Typical UK prices with supply and fit included. Compare by style, material or property type.
| Window Style | uPVC | Aluminium | Timber |
|---|---|---|---|
| Casement | £400–£1,000 | £540–£1,350 | £760–£1,900 |
| Sash | £600–£1,500 | £950–£2,030 | £1,330–£2,850 |
| Tilt & Turn | £500–£1,200 | £680–£1,620 | £950–£2,280 |
| Bay (per bay) | £1,250–£3,000 | £1,690–£4,050 | £2,380–£5,700 |
| Fixed | £300–£760 | £410–£1,030 | £570–£1,440 |
| French Doors | £1,100–£2,200 | £1,490–£2,970 | £2,090–£4,180 |
| Bifold Doors | £2,000–£4,675 | £3,000–£7,500 | £3,800–£8,550 |
| Material | Typical per window | Best for |
|---|---|---|
| uPVC | £400–£1,000 | Best value, low maintenance, excellent insulation |
| Aluminium | £540–£1,350 | Slim frames, modern look, very durable |
| Timber | £760–£1,900 | Period and listed properties, premium finish |
| Property Type | Typical windows | Full-house range |
|---|---|---|
| Flat | 4 windows | £1,800–£5,000 |
| Terraced | 8 windows | £4,000–£10,000 |
| Semi-Detached | 10 windows | £5,000–£12,000 |
| Detached | 14 windows | £7,000–£16,500 |
Prices include supply and installation. Costs vary by region, London & the South East are typically 15–25% higher.
Three Typical Jobs, Priced
Worked from the price table above, and you can load any of them into the calculator to change the details
Terraced house
8 x uPVC casement, double glazed
£3,200–£8,000
Semi-detached house
10 x aluminium casement, triple glazed
£5,940–£16,200
Detached house
14 x timber casement, double glazed
£10,640–£26,600
Window Types Guide
The pros, cons and typical cost of each style
| Style | Typical cost | Pros | Cons | Best for |
|---|---|---|---|---|
| Casement | £400–£1,900 | Affordable, great seal, versatile. | Limited opening styles. | Most modern UK homes. |
| Sash | £600–£2,850 | Classic period look, great ventilation. | Pricier, more maintenance. | Victorian and period homes. |
| Tilt & Turn | £500–£2,280 | Flexible opening, easy to clean. | Bulkier frames. | Flats and upper floors. |
| Bay | £1,250–£5,700 | Adds space and light, kerb appeal. | Expensive, complex fit. | Living rooms and period fronts. |
| French Doors | £1,100–£4,180 | Elegant, wide opening to the garden. | Needs clearance space. | Patios and dining rooms. |
| Bifold Doors | £2,000–£8,550 | Fully opens, stunning indoor-outdoor flow. | Premium price. | Modern extensions and kitchens. |
Each range runs from uPVC at the low end to timber at the high end, per window, supply and fit included.
Double Glazing Calculators by Style and Material
Price one window style, material or job at a time, on the same 2026 figures as the calculator above
uPVC Window Calculator
The default for most UK homes. Price fitted uPVC casement, sash and tilt-and-turn windows.
Casement Window Calculator
The cheapest, most common style, priced in any frame material.
Sash Window Calculator
Vertical sliding sash windows for Victorian and Georgian homes, in uPVC or timber.
Bay Window Calculator
Projecting bay windows priced per bay, including the structural fitting work.
Door Cost Calculator
Front, French, patio and bifold doors, supply and fit, in uPVC, composite and aluminium.
Energy Savings Calculator
See how much A-rated double glazing could trim from your annual heating bill.
Double Glazing Comparisons, Side by Side
uPVC against aluminium, double against triple, repair against replace: the choices that move your final bill the most
uPVC vs Aluminium
Slim modern frames against the budget default, comparing looks, lifespan and the price gap.
Double vs Triple Glazing
Is the third pane worth it? Heat loss, noise and payback compared.
Supply-Only vs Fully Fitted
Fit it yourself or pay for installation, and what each route really costs.
uPVC vs Timber
Low-maintenance plastic against authentic wood for period and conservation homes.
Repair vs Replace
Misted or draughty units? When a fix beats a full replacement.
Casement vs Sash
Two classic styles compared on cost, looks and which suits your home.
Learn How Double Glazing Pricing Really Works
Plain-English guides to specs, costs and avoiding a bad quote
Cost Per Window
What a single window really costs in 2026, broken down by style and material.
Is Double Glazing Worth It?
The payback maths on bills, comfort and resale value.
How to Avoid Being Overcharged
The sales tactics to watch for and how to read a quote like an installer.
U-Values Explained
What the U-value on your quote means, and why a lower number is better.
FENSA Explained
Building-regs sign-off, certificates, and why they matter when you sell.
Single vs Double vs Triple
How each glazing type performs on heat loss, noise and cost.
Double Glazing Costs by House Size & Region
See where your home and postcode land on the 2026 price range
Latest Grants & Policy Updates
Changes to EPC rules, grants and schemes that affect window costs
The Warm Homes Plan 2026 explained
The government's roughly £15bn home-energy programme reshapes window grants.
The October price cap rose 4%, nearly all gas
A typical household is put at £1,723 a year, and the rise lands on the fuel windows work on.
ECO4 extended to December 2026
ECO4 gains a nine-month extension to 31 December 2026, with no successor scheme after.
Independent, sourced and free
No salespeople and no inflated numbers, just installer-checked 2026 costs — given as a low-to-high range, because real quotes vary with access, glass spec and region.
Cross-checked against three independent sources
Every price range is checked against Checkatrade, the FMB and GreenMatch before it goes live, and dated so you can see how current it is.
Transparent, sourced 2026 pricing
We publish where our numbers come from and how each estimate is built, so you can sanity-check the figure yourself.
No signup, no lead-selling
Use every calculator free, with no email wall. We only pass your details to an installer if you ask us to.
Frequently Asked Questions
Everything UK homeowners ask about double glazing costs
Most UK homeowners pay between £4,000 and £10,000 to replace all windows in an average semi-detached house in 2026. A flat might cost £1,800 to £5,000, while a large detached home can reach £7,000 to £16,500 or more, depending on the number of windows, frame material and glazing.
Yes. uPVC is the most affordable frame material: aluminium costs roughly 30 to 40% more than the equivalent uPVC window, and timber 60 to 110% more, while uPVC still delivers excellent thermal performance. Aluminium earns its premium with slimmer frames and a sleek, modern look.
Triple glazing adds roughly 10 to 20% to the price. It improves insulation and noise reduction, making it most worthwhile in colder regions, near busy roads, or for very energy-conscious homes. For many homes, good-quality A-rated double glazing offers the best value.
A typical installer fits 4 to 6 windows per day, so an average house is usually completed in 1 to 3 days. Larger homes or complex installs such as bay windows can take a little longer.
Usually not. Replacing like-for-like windows falls under permitted development. However, listed buildings and homes in conservation areas often need consent, so always check with your local planning authority first.
Replacing single glazing with A-rated double glazing can save around £85 a year in Great Britain and £140 a year in Northern Ireland on a typical semi-detached house, according to the Energy Saving Trust. The exact figure varies by house size, region and your current windows.
The main routes changed in 2026. ECO4 was extended and now runs to 31 December 2026, with no successor scheme after it. In England, the Warm Homes: Local Grant is the headline scheme, offering up to £15,000 for fabric measures including glazing (plus up to £15,000 for low-carbon heating) for lower-income households in EPC bands D to G. Scotland has Home Energy Scotland loans, and only around 15% of households qualify for funding overall, so check eligibility before assuming free windows.
Quality double glazing lasts around 20 to 25 years for uPVC frames, 30 to 40 years for aluminium, and 30 to 60 years for well-maintained timber. The sealed glass unit itself typically lasts 15 to 20 years before any misting. Most reputable installers offer a 10-year guarantee.
Installers are often quieter (and sometimes cheaper) in autumn and winter, so you may get better deals. Installation can be done year-round, because fitters only remove one window at a time, so your home is not left exposed.
How to Compare Installer Prices Before You Commit
The estimate above is a starting point, not the final price. Written installer quotes are what you actually pay — and they only mean something when every one of them covers the same job.
Get three quotes, not one
Prices for the same job vary between installers, so a single number tells you nothing. Three only help if you compare them like-for-like: match the spec and insist on it in writing.
Check the price per window
Divide the total by the number of windows and benchmark the result against fair 2026 UK prices. It is the quickest way to see whether a quote sits inside the range or outside it.
Send every installer the same spec
Use your estimate as the brief, so each quote covers the same unit count, glass spec and hardware. We pass your details to up to four local installers, and only if you ask us to.