Double Glazing Cost UK 2026: Per Window & Whole House Prices
Double glazing in the UK costs £400-700 per uPVC window, £700-1,400 per aluminium window and £900-1,800 per timber window, all fully fitted, in 2026. A complete 3-bed semi (8-10 windows) runs £4,000-6,000 in uPVC, rising to £7,000-10,000 in aluminium. This guide uses verified Q3 2026 pricing from window installers across 519 UK towns, broken down by frame material, window style, glazing spec and house size.
Double Glazing Cost UK 2026: Quick Answer
In 2026, double glazing costs £400-700 per uPVC window, £700-1,400 per aluminium window and £900-1,800 per timber window, all supplied and fitted. A typical 3-bed semi-detached house (8-10 windows) costs £4,000-6,000 in uPVC, £7,000-10,000 in aluminium and £10,000-16,000 in timber. Triple glazing adds roughly 15-40% over double. Prices are 15-25% higher in London and the South East. Replacement windows must be fitted by a FENSA or CERTASS registered installer to meet Building Regulations.
Jump to: Cost by material · Cost by window style · Whole-house cost · Double vs triple · Energy savings & ratings · FENSA & certificates · FAQs
Double Glazing Cost Per Window by Frame Material (2026)
The single biggest factor in your double glazing cost is the frame material. The four mainstream choices in the UK are uPVC (by far the most common and the cheapest), aluminium (slim, modern, premium), timber (heritage and period homes) and composite aluminium-clad timber (best of both, highest cost). The table below shows typical 2026 fitted prices for a standard casement window of around 1200 x 1200mm. Smaller windows cost less; larger or made-to-measure units cost more.
| Frame material | Per window (fitted) | Typical lifespan | Best for |
|---|---|---|---|
| uPVC | £400 - £700 | 20-35 years | Best value, low maintenance, most homes |
| Aluminium | £700 - £1,400 | 30-45 years | Slim sightlines, large glass, modern look |
| Timber (softwood) | £900 - £1,500 | 30-60 years (maintained) | Period & character properties |
| Timber (hardwood/oak) | £1,200 - £2,500 | 40-60 years | Premium heritage & listed homes |
| Composite (alu-clad) | £1,000 - £2,000 | 40-60 years | Low maintenance with timber interior |
Notes: Prices are supply-and-fit including VAT and standard removal of the old window for a standard 1200 x 1200mm casement. London and the South East typically add 15-25%. Installation (labour) usually accounts for 20-40% of the total, around £150-£400 per window depending on access and complexity.
uPVC remains the default for most UK homeowners: it is the cheapest, needs almost no maintenance, and modern uPVC frames easily achieve an A energy rating. Aluminium costs 50-100% more but its strength allows much slimmer frames and bigger panes of glass, making it the go-to for contemporary extensions and large picture windows. Timber is chosen for period authenticity, especially in conservation areas, but needs repainting every 5-10 years. Composite frames give you a maintenance-free aluminium exterior with a warm timber interior, at the top of the price range. For a broader view of frame materials, window styles and how to pick an installer, our double glazing service hub pulls the whole decision together in one place.
Double Glazing Cost by Window Style & Type
Beyond the frame material, the style of window has a big effect on price. A plain casement is the cheapest option; sliding sash, bay, bow and tilt-and-turn windows all cost more because of extra glass, more complex mechanisms or heritage detailing. The table below shows typical 2026 fitted prices in uPVC (the most popular material) for each common window style. Aluminium and timber versions of the same style cost proportionally more, in line with the material table above.
| Window style | uPVC fitted price | Notes |
|---|---|---|
| Fixed (non-opening) | £300 - £550 | Cheapest; no hinges or hardware, glass only |
| Casement (standard) | £400 - £700 | The UK default; hinged at the side or top |
| Tilt-and-turn | £500 - £1,100 | Opens two ways; 15-25% premium over casement |
| Sliding sash (vertical) | £600 - £1,200 | uPVC alternative to a traditional box sash |
| Bay window (3 panel) | £1,500 - £2,800 | Priced as a unit; needs a structural sub-frame |
| Bow window (4-5 panel) | £2,000 - £3,500 | Curved; more panes than a bay |
| French / patio casement | £700 - £1,400 | Larger glazed area; often paired with doors |
Notes: Bay and bow windows are quoted as a complete assembly, not per pane. Heritage-style sash and astragal (Georgian) bar detailing adds £100-£300 per window. Coloured or woodgrain foils (e.g. Anthracite Grey, the most popular non-white finish in 2026) typically add 10-20%.
If you live in a period or conservation-area property, a uPVC sliding sash is the budget-friendly way to keep the look of a traditional box sash, while a genuine timber sash preserves full authenticity at a higher cost. For a deeper breakdown of sash pricing, see our dedicated sash window cost guide.
Cost to Double Glaze a Whole House by Property Size
Most people search for the total cost to double glaze a house, which depends mainly on the number of windows and the frame material. As a rule of thumb, a small terrace has 5-7 windows, a 3-bed semi has 8-10, and a detached home has 12-15 or more. The table below shows typical 2026 whole-house fitted costs in uPVC, with aluminium and timber multipliers underneath.
| Property type | Typical windows | uPVC (fitted) | Aluminium (fitted) | Timber (fitted) |
|---|---|---|---|---|
| Flat / small terrace | 4-6 | £2,500 - £4,000 | £4,000 - £6,500 | £5,500 - £9,000 |
| Mid terrace (2-3 bed) | 6-8 | £3,500 - £5,500 | £5,500 - £8,500 | £8,000 - £13,000 |
| 3-bed semi-detached | 8-10 | £4,000 - £6,000 | £7,000 - £10,000 | £10,000 - £16,000 |
| 4-bed detached | 12-15 | £6,000 - £9,000 | £10,000 - £15,000 | £15,000 - £24,000 |
| Large detached / period | 16+ | £9,000 - £14,000 | £15,000 - £22,000+ | £24,000 - £40,000+ |
Notes: Costs are for windows only and include VAT, fitting and removal of the old units. Doors (front, back, French or bi-fold) are extra. Buying all windows in one order is significantly cheaper per window than replacing a few at a time, because the installer makes a single visit. London and the South East: add 15-25%.
A common question is whether to replace all windows at once or phase the work. Doing the whole house in one go is almost always cheaper per window and gets you a single FENSA or CERTASS certificate covering every opening. Phasing spreads the cost but means repeated installer visits and potentially mismatched frames over time. If budget is tight, prioritise the rooms losing the most heat, usually north-facing rooms and any with old single glazing or failing sealed units. Where only a few units have misted up rather than the frames themselves having failed, replacing the sealed glass alone is often far cheaper than a whole new window, so it is worth checking our blown window repair cost guide before replacing the lot.
Double Glazing vs Triple Glazing: Cost & U-Values Compared
Triple glazing adds a third pane of glass and a second insulating cavity, improving both thermal and acoustic performance. The headline question is whether the extra cost is worth it. In 2026, triple glazing costs roughly 15-40% more than double, but the additional annual energy saving over good A-rated double glazing is modest, typically only £20-50 per year, giving a payback of 20 years or more.
| Factor | Double glazing | Triple glazing |
|---|---|---|
| Panes of glass | 2 (one cavity) | 3 (two cavities) |
| Typical U-value (W/m²K) | 1.2 - 1.6 | 0.8 - 1.0 |
| uPVC price per window (fitted) | £400 - £700 | £550 - £950 |
| Cost premium | Baseline | +15% to +40% |
| Extra annual saving | Baseline | ~£20 - £50 / year |
| Noise reduction | Good | Better (heavier glass helps) |
| Best for | Most UK homes | New builds, exposed/noisy sites, Passivhaus |
Notes: U-value measures heat loss; lower is better. Energy Saving Trust and most installers agree the single-to-double upgrade delivers the big savings, while double-to-triple is incremental. Triple units are heavier, so very large openings may need reinforced frames.
The verdict for 2026: for the average UK home, a well-installed A-rated double-glazed window with low-E glass, a warm-edge spacer and argon fill is the best value. Choose triple glazing if you are building new (where the marginal cost is lower), live somewhere very exposed or noisy, want maximum comfort in north-facing rooms, or are targeting Passivhaus-level efficiency. For most other homeowners, putting the money saved towards better frames, doors or loft insulation will give a faster return.
Energy Savings, Bills & Window Energy Ratings (WER)
Energy efficiency is a major reason people upgrade their windows. Modern double glazing can cut heat loss through windows by about a quarter compared with single glazing, and reduces draughts, condensation and outside noise. The exact saving depends on what you are replacing: the biggest gains come from going single glazing to A-rated double, with much smaller gains from upgrading already-modern units.
| Upgrade | Typical annual bill saving* | Comfort benefit |
|---|---|---|
| Single glazing → A-rated double | £80 - £195 | Large: warmer, far fewer draughts |
| Old (pre-2002) double → A-rated double | £45 - £110 | Noticeable: less misting, better seals |
| A-rated double → A++ / triple | £20 - £50 | Marginal energy; better noise & comfort |
*Indicative whole-home figures based on Energy Saving Trust data at 2026 energy prices for a typical gas-heated semi. Actual savings vary with property size, heating system, how many windows you replace and your tariff.
Window Energy Ratings explained (A++ to E)
Every new window carries a Window Energy Rating (WER), a colour-coded scale from A++ (best) down to E, like the label on a fridge. It balances heat lost through the window against free solar heat gained, so a higher band means a more efficient window overall. The related U-value measures heat loss alone, where lower is better.
| WER band | Typical U-value (W/m²K) | What it means |
|---|---|---|
| A++ | ~0.8 - 1.0 | Best available; usually triple glazing |
| A+ / A | ~1.2 - 1.4 | Excellent double glazing; the 2026 sweet spot |
| B | ~1.4 - 1.6 | Building Regs minimum for replacements |
| C - E | 1.6+ | Below current standard; avoid for new installs |
Notes: Under Building Regulations Part L, replacement windows must achieve at least a WER of band B or a U-value of 1.4 W/m²K or lower. Most reputable installers fit A-rated as standard. Performance comes from low-emissivity (low-E) glass, argon gas fill and warm-edge spacer bars, not just the number of panes.
FENSA, CERTASS & Building Regulations Part L
Since 2002 it has been a legal requirement that replacement windows and doors comply with Building Regulations. The simplest way to meet this is to use an installer registered with a government-authorised Competent Person Scheme, the two main ones being FENSA and CERTASS. A registered installer can self-certify the work and issue a Building Regulations Compliance Certificate, so you do not need to involve your local council building control.
| Scheme | What it is | Certificate speed | Notes |
|---|---|---|---|
| FENSA | Largest, oldest Competent Person Scheme | ~2-4 weeks | Most common; widely recognised by buyers |
| CERTASS | Equivalent UKAS-approved scheme | ~7 days | Legally identical; often faster certificate |
| Council Building Control | Used if installer is not registered | Varies | Extra fee; needed if no scheme certificate |
Notes: There is technically no such thing as a standalone "FENSA certificate" — the legal document is a Building Regulations Compliance Certificate, which FENSA, CERTASS and other schemes can all issue. They are legally equivalent.
Why the certificate matters when you sell
When you sell your home, the buyer's conveyancer will ask for the compliance certificate for any windows fitted since April 2002. Missing paperwork can delay or jeopardise a sale and may force you to buy indemnity insurance or apply for retrospective building control sign-off. Always keep your FENSA or CERTASS certificate safe; if you have lost it you can usually order a replacement online from the scheme. This is one of the strongest reasons to insist on a registered installer rather than a cash-in-hand fitter.
National brands vs local installers
Big names such as Anglian, Everest and Safestyle advertise heavily, but it is worth knowing that all three now sit under the same ownership following acquisitions in 2023-2024, so three of those quotes are not three independent prices. National firms typically quote 30-60% more than an established local FENSA or CERTASS installer for a comparable specification, partly to cover sales and marketing costs. A reputable local installer usually offers better value and a more personal service. Whichever route you take, get at least three written quotes, check the firm's scheme registration and read recent reviews before signing.
What Affects the Cost of Double Glazing?
Two homes of the same size can receive very different quotes. These are the main factors that move the price up or down in 2026:
- Frame material — uPVC is cheapest; aluminium, timber and composite cost progressively more (see the material table above).
- Window size and style — bigger glass, sash mechanisms, bay and bow assemblies all add cost over a plain casement.
- Glazing specification — triple glazing, acoustic glass, self-cleaning or solar-control glass and Georgian bars all add 10-40%.
- Number of windows — ordering the whole house at once lowers the price per window because the installer makes one visit.
- Colour and finish — white is standard; foiled colours such as Anthracite Grey typically add 10-20%.
- Access and floor level — upper-floor windows needing scaffolding or working over a conservatory cost more to fit.
- Location — London and the South East run 15-25% above the national average; the North and parts of Wales and Scotland are below.
- Installer type — national brands cost more than equivalent local FENSA/CERTASS firms.
- Property type — conservation areas and listed buildings may require heritage frames or specific glazing, raising the cost.
Because so many variables are involved, the only reliable way to know your real cost is to get itemised written quotes for your exact windows. Use the form below to receive free, no-obligation quotes from registered installers covering your area.
What's Included in a Double Glazing Price
A fair double glazing quote should be fully itemised so you can see exactly what you are paying for. A complete supply-and-fit price for a standard uPVC casement of around £400-700 normally covers much more than the window on its own.
- Supply of the window — the made-to-measure frame, sealed glass unit, low-E coating, argon fill and warm-edge spacer bars.
- Fitting labour — usually £150-400 per window, typically 20-40% of the total price.
- Removal and disposal — taking out and recycling your old frames and glass.
- Making good — re-plastering or filling the internal reveals and fitting new trims, sills and silicone seals.
- Building Regulations Compliance Certificate — issued by a FENSA or CERTASS registered installer at no extra charge.
- VAT and guarantee — VAT at the standard rate plus the installer's own workmanship guarantee, commonly 10-20 years.
Notes: if a quote looks unusually cheap, check whether removal, making good, the compliance certificate or VAT have been left out. A per-window breakdown makes it easy to compare installers like for like.
Ask every installer to price each window separately as well as giving a whole-house total. To sanity-check a figure before you book a survey, try our double glazing cost calculator, or if you are also weighing up a glazed extension see our conservatory cost guide.
How Long Does It Take to Fit Double Glazing?
Once you have signed off a quote, replacing the windows in a whole house is quicker than most people expect. Most of the wait is manufacturing lead time, not the fitting itself. A typical 2026 timeline looks like this:
| Stage | Typical timing | What happens |
|---|---|---|
| Technical survey | 1-2 hours, within ~1 week | Exact measurements taken after you accept the quote |
| Manufacturing lead time | 3-6 weeks | Made-to-measure frames and sealed units are built to order |
| Fitting on site | 1-2 windows per fitter per day | A 3-bed semi (8-10 windows) usually takes 2-4 days |
| Making good & clean-up | Same day as fitting | Reveals filled, trims fitted and old units removed |
| Compliance certificate | ~1-4 weeks after fitting | FENSA (~2-4 weeks) or CERTASS (~7 days) issues the certificate |
Notes: access matters — upper-floor windows needing scaffolding, and bay or bow assemblies, can each add a day. Large detached homes typically take 4-7 days on site.
Because the frames are made to order, most of the timeline is fixed regardless of installer, so a firm promising same-week fitting may be using stock sizes rather than made-to-measure units. Booking the whole house in one visit is faster per window and gets you a single compliance certificate covering every opening. If you are replacing external doors at the same time, having them fitted on the same visit usually works out cheaper; our external door fitting cost guide covers that, while the double glazing cost index tracks how these prices are moving across UK towns.
Window brands compared: Rehau, Veka, Deceuninck, Origin, Everest and Anglian
Two very different things get called a "brand" here: the profile system your local fabricator uses, and the national installer selling you the finished window. It is worth knowing which one you are being quoted.
| Brand | Known for | Ranges you will be quoted | Typical price per window | Worth knowing |
|---|---|---|---|---|
| Anglian | National installer, full-service model | Anglian windows | £750–£1,500 | Also sold installed; discounting from list is common |
| Deceuninck | Profile system with good flush-sash options | Heritage Flush Sash, 2800 | £500–£1,000 | Flush sash suits period properties and conservation areas |
| Everest | National installer selling its own product | Everest windows | £800–£1,600 | Sold installed - compare the total against two local fabricators |
| Origin | British aluminium; long guarantee | OW-70 windows, OB-49 doors | £900–£1,800 | Aluminium, so slimmer sightlines than uPVC at a higher price |
| Rehau | German uPVC profile used by many UK fabricators | TOTAL70, RIO | £450–£900 | A profile system, not an installer - your local fitter buys it in |
| Veka | Widely used uPVC profile; strong reputation | Halo, Matrix | £450–£900 | Another profile system; ask which fabricator makes the finished frame |
Prices above are for the window only — fitting is separate and is priced in the table further up this page. Brands are listed alphabetically, not ranked: BestBuilders does not sell or endorse any of them.
Double Glazing Cost by UK Region (2026)
The same job costs more in London and the South East and less in the North, Wales and Scotland, mostly through labour rates. The table shows BestBuilders’ 2026 regional cost model — national cost guides adjusted by a regional labour index and averaged across the towns in each region — for the main double glazing job types.
Indicative ranges, not quotes: your own price depends on specification, access and the installer’s workload. Get three itemised quotes to pin your figure down.
Registered members: Double Glazing
3 businesses offering double glazing have a public profile with BestBuilders. Each listing is a business that registered with us directly; the details shown are the ones it declared at registration, and a Companies House number appears only where one was given.
All registered trades · Recent projects · Run a double glazing business? Add your free profile
What homeowners asked us for — Double Glazing (last 90 days)
444 homeowners started a quote request for double glazing through the BestBuilders quote tool between 10 Jun – 8 Sep 2026, UK-wide. These are their own answers to the tool’s questions, aggregated and anonymised — not a model, not an estimate.
What double glazing work do you need doing?
- 73% Install new glazing
- 23% Repairing existing glazing
- 4% Other
52 answers
What is the type of property?
- 93% Residential
- 3% House
- 2% Flat
- 2% Commercial premises
59 answers
Do you own the property?
- 84% Yes
- 16% No
44 answers
Which is your preferred frame material?
- 68% UPVC
- 12% Wood
- 12% Aluminium
- 7% I'm not sure
41 answers
Source: BestBuilders quote-tool answers, 10 Jun – 8 Sep 2026. Percentages are of the homeowners who answered each question; figures update daily. See the UK homeowner demand index for every trade.
Double Glazing Cost FAQ · UK 2026
In 2026 a typical 3-bed semi with 8-10 windows costs around £4,000-6,000 for uPVC double glazing fitted, £7,000-10,000 for aluminium and £10,000-16,000 for timber. A 3-bed terrace with fewer windows can start near £3,500, while a larger detached home with 12-15 windows runs £6,000-9,000 in uPVC. Add 15-25% in London and the South East. Always compare at least three FENSA or CERTASS registered installers.
Fitted per-window prices in 2026 are roughly £400-700 for a standard uPVC casement, £700-1,400 for aluminium and £900-1,800 for timber. Composite (alu-clad timber) sits at £1,000-2,000. Sash windows, bay windows and tilt-and-turn styles cost more than a plain casement. The price per window falls as the order size grows, because the installer spreads fixed visit and scaffolding costs over more units.
uPVC is the best value and the most thermally efficient at the budget end, typically £400-700 per window, with low maintenance and a 20-35 year lifespan. Aluminium costs roughly 50-100% more but offers slimmer sightlines, larger glass area, a premium modern look and a 30-45 year lifespan, which suits contemporary or large-format glazing. For most UK homes on a budget uPVC wins; for design-led projects or big picture windows, aluminium is worth the premium.
For most UK homes triple glazing is not worth it on energy savings alone. It costs about 15-40% more than double glazing but only saves an extra £20-50 a year, giving a payback of 20 years or more. Triple glazing makes the most sense in new builds, very exposed or noisy locations, north-facing rooms or to Passivhaus standard. A good A-rated double-glazed unit with a U-value around 1.2-1.4 already performs very well for the money.
Quality double glazing lasts 20-35 years on average. The sealed glass units themselves typically last 15-25 years before the seal can fail and cause misting, while the frames usually outlast the glass: uPVC lasts 20-35 years, aluminium 30-45 years and well-maintained timber 30-60 years. Signs you need replacement include condensation between the panes, draughts, sticking handles and rising heating bills. Many installers offer a 10-20 year guarantee.
Yes. Since 2002 all replacement windows and doors must comply with Building Regulations. The easiest route is to use a FENSA or CERTASS registered installer, who self-certifies the work and issues a Building Regulations Compliance Certificate. Without it you may need a building control completion certificate from the council, and you will usually be asked for the certificate when you sell. FENSA and CERTASS are legally equivalent, and you can order a replacement online if you lose yours.
FENSA and CERTASS are both government-authorised Competent Person Schemes that let window installers self-certify that their work meets Building Regulations Part L. They are legally equivalent and both issue a Building Regulations Compliance Certificate accepted by conveyancers when you sell. FENSA is older and larger, so you will meet it more often, while CERTASS typically issues certificates faster, often within 7 days versus 2-4 weeks. Either is fine; what matters is that your installer is registered with one of them.
Replacing single glazing or old pre-2002 units with modern A-rated double glazing can cut heat loss through windows by around a quarter and save roughly £80-195 a year on a typical home at 2026 energy prices, according to Energy Saving Trust figures. The biggest savings come from going single to double; upgrading already-decent double glazing to A++ or triple saves much less. Better windows also reduce draughts, condensation and outside noise.
The Window Energy Rating (WER) is a colour-coded scale from A++ down to E, similar to a fridge label, showing how energy efficient a whole window is by balancing heat lost against solar heat gained. A++ is the best available and A is the minimum most reputable installers fit in 2026. Building Regulations require replacement windows to hit at least a WER of band B, or a U-value of 1.4 W/m²K or lower. A-rated double glazing is the sweet spot for value; A++ usually means triple glazing.
A standard uPVC casement window costs around £400-700 fitted in 2026, while a uPVC vertical sliding sash window (the modern double-glazed replacement for a traditional box sash) costs around £600-1,200 fitted. Timber sash windows cost considerably more, typically £1,200-2,500 each. Sash windows are pricier because of the more complex sliding mechanism and the heritage detailing often required in conservation areas. See our sash window cost guide for a full breakdown.
Usually yes. National brands such as Anglian, Everest and Safestyle (now all under the same ownership) often quote 30-60% more than an established local FENSA or CERTASS installer for a comparable specification, partly to cover heavy advertising and sales costs. National firms can offer strong guarantees and finance, but a reputable local installer normally gives better value and a more personal service. Whoever you choose, get three written quotes and check their certification before signing.
Standard window replacement is not usually grant-funded, but if you are on a low income or certain benefits you may qualify for help under the ECO4 scheme or the Warm Homes: Local Grant, which can fund energy efficiency measures including glazing as part of a wider home upgrade. Eligibility depends on income, benefits, your property EPC rating and your local authority. These schemes change frequently, so check the current rules on GOV.UK before assuming you qualify.
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Related Cost Guides
Planning more home improvements? Compare 2026 UK costs across our other guides:
- Sash Window Cost UK 2026 — timber vs uPVC sliding sash, heritage and conservation-area pricing.
- Roofing Cost UK 2026 — re-roof, repair and flat-roof prices by material and house size.
- House Extension Cost UK 2026 — single and double-storey extension costs per m².
- Boiler Replacement Cost UK 2026 — combi, system and heat-pump pricing plus grants.
Sources, Data & Editorial Standards
The figures on this page are compiled from BestBuilders' 2026 regional cost model across 519 UK towns, cross-checked against the following industry and government sources:
- FENSA — Fenestration Self-Assessment Scheme: Competent Person Scheme rules and Building Regulations Compliance Certificates.
- CERTASS — UKAS-approved Competent Person Scheme for window and door installation certification.
- GGF — Glass and Glazing Federation: industry standards, Window Energy Ratings and glazing specifications.
- Building Regulations Part L (Conservation of fuel and power) — minimum U-value and WER requirements for replacement windows.
- Energy Saving Trust — energy efficiency and bill-saving estimates for glazing upgrades.
- GOV.UK — ECO4 and Warm Homes: Local Grant eligibility for energy efficiency measures.
Methodology: per-window and whole-house ranges reflect typical supply-and-fit prices including VAT for standard specifications, before regional adjustment. Prices are guide figures only; your quote depends on your exact windows, access and location. We do not accept payment to alter pricing.Reviewed by the BestBuilders editorial team · Last updated: 1 September 2026; next review November 2026. Read our full /editorial-standards.
Double glazing — guides and detail
The detail behind the number: what changes the price, the planning position, and how to check a quote before you accept it.