Double Glazing Costs 2026
A single uPVC casement runs about £650 fitted in 2026, and a whole average semi sits between £4,000 and £10,000. Here is the full breakdown.
Double glazing is priced per window and then totalled, so the two levers that move your bill most are how many windows you replace and which frame material you choose. The tables below are 2026, fully fitted figures: they include the unit, labour, the removal and disposal of the old windows, sealing and the FENSA certificate. We cross-checked these prices across Checkatrade, the FMB and GreenMatch, and they were price-checked by Tom Bradley, a window installer with over 20 years fitting windows. To turn these figures into a price for your own home, use the double glazing cost calculator, and for the one-line versions of the queries behind these tables see the double glazing questions answered on this site. You can read the full method on our methodology page.
Cost per window by style
Style matters because a vertical sliding sash or a projecting bay is far more work to make and fit than a flat casement. A curved bow, an inward-opening tilt and turn, a French pair, a flush casement or a fixed picture window each price differently again. The ranges below are per window, supply and fit, across all three common frame materials. For the casement-by-casement detail, see our guide to cost per window or run the uPVC window calculator.
| 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) | £1,100–£3,000 | £1,490–£4,050 | £2,090–£5,700 |
| Fixed | £220–£440 | £300–£590 | £420–£840 |
| French Doors | £1,100–£2,200 | £1,490–£2,970 | £2,090–£4,180 |
| Bifold Doors | £2,200–£5,500 | £2,970–£7,430 | £4,180–£10,450 |
Casement is the cheapest entry point and the row most homes should price first.
What these prices are checked against
The published UK cost guides do not agree with each other, and pretending otherwise would be dishonest on a page where people are about to spend five figures. The table below prices the same two windows across three named sources and our own model, so you can see the spread rather than take one number on trust.
| Source | uPVC casement | Timber casement | Basis |
|---|---|---|---|
| Checkatrade (2026 guides) | £500 to £1,250 | £900 to £1,500 | Fitted; timber row is 1200 x 1200mm |
| FMB (July 2026) | £670 | £1,975 | Fitted, 1200 x 1200mm |
| GreenMatch | £160 to £825 | £240 to £1,240 | Unit price, installation excluded |
| This site | £400 to £1,000 | £760 to £1,900 | Fitted, mainstream consensus |
Sources: Checkatrade, FMB and GreenMatch cost guides, fetched 29 July 2026.
On a 1200 x 1200mm timber casement the FMB publishes £1,975 against Checkatrade at £900 to £1,500. That is more than double at the low end, for the same product. Meanwhile GreenMatch lists per-window prices that exclude installation entirely, which is why its figures look so much cheaper. Our ranges sit on the mainstream consensus across those sources, not the premium end one guide can lean towards. A quote above our range is not automatically wrong. Read the methodology page for how we reconcile them.
Cost by frame material
uPVC is the baseline. Aluminium buys you slimmer sightlines and a longer life for a 30 to 40% premium, while timber is a period and conservation-area choice that can cost roughly double. The maintenance column is the part buyers forget: only timber needs repainting, and that kind of trade-off is what our double glazing comparisons are built to settle. To weigh frames directly, read uPVC versus aluminium, then work through the other double glazing comparisons that pit glass, styles and buying routes against each other.
| Material | Per window | Lifespan | Maintenance | Best for |
|---|---|---|---|---|
| uPVC Best Buy | £400-£1,000 | 20-25 yrs | None | Most modern UK homes; best value |
| Aluminium Worth it | £550-£1,300 | 30-40 yrs | None | Slim modern frames, large openings |
| Timber It depends | £900-£2,000 | 30-60 yrs | Repaint every 8-10 yrs | Period and conservation-area homes |
What actually moves your quote up or down
Two houses with the same number of bedrooms can be thousands of pounds apart, and it is rarely the windows that explain it. The unit is a commodity. What varies is how hard it is to get that unit into your wall. Anything needing scaffolding, a two-man lift, a parking suspension or a structural repair moves you up. The extras below are the ones that most often arrive as a surprise line on the final invoice.
| Extra | Typical 2026 cost | When it applies |
|---|---|---|
| Scaffolding hire | Around £1,000 a week | Upper floors with no safe ladder access, or a job over a conservatory or extension roof |
| Triple glazing upgrade | Around 10 to 20% more | Cold or noisy sites; heavier units can also need stronger frames |
| Coloured aluminium frames | Around 10 to 20% more | Black, anthracite and other powder-coat finishes over standard silver |
| Contingency for hidden repairs | 10 to 15% of the job | Rotten timber, failed lintels or crumbling reveals found once the old frame is out |
| Architect or specialist drawings | £900 to £1,500 | Listed building consent and heritage applications |
Sources: Checkatrade double glazing and aluminium cost guides; FMB new windows guide; Energy Saving Trust.
Three more items rarely carry a published price but routinely move a quote. A bay is the big one: it is priced per bay, not per window, at £1,100 to £3,000 in uPVC, because a projecting bay often carries load and needs propping and reinstating rather than a simple swap. A failed or missing lintel found on removal is a structural job that halts the fit until it is put right. Disposal and making good should be in the quote, but Checkatrade lists both among the items installers commonly leave out, so confirm them in writing. Our removal and disposal guide covers that work.
How to read a double glazing quote line by line
A quote you cannot break down is a quote you cannot compare. Ask for it itemised. Checkatrade says a standard quote should include removal of the existing windows, supply and installation of the new ones, standard glazing and window furniture, labour, basic making good, waste removal and VAT, with FENSA or CERTASS certification, guarantees, trickle vents and upgraded locks sometimes included and sometimes not.
The FMB adds the questions that separate a real quote from a sales document. Does it state the style, size, frame material, glass type and quantity for every opening, including whether the units are low-emissivity and gas filled? Is labour a flat fee or per window, and does it cover preparing the apertures as well as fitting? Does it name the warranty length for both the units and the workmanship? Does it set out the deposit, the payment schedule and the start and finish dates? Anything missing is something you will be charged for later or have no recourse on. Our guide to getting three quotes covers how to compare them like for like. The practical follow-ups a quote raises, what a normal deposit looks like and whether new windows add value when you sell, sit in the costs and value section of our double glazing FAQs, so the Double Glazing FAQs index is the quicker route to those.
What a fair labour split looks like
Knowing what the fitting is worth tells you whether the rest of the number is reasonable. Checkatrade puts double glazing installers at £25 to £35 an hour, or around £600 a day for a team of two, and a typical three-bed house at two to four days of work. That is roughly £1,200 to £2,400 of labour on a whole-house job. Against a semi at £4,000 to £10,000, labour is somewhere between a fifth and a third of the bill, with the balance on the units, the glass, disposal, sealing, certification and the firm's overheads and margin. If you strip the fitting out entirely, our supply-only versus fully fitted comparison shows what is left.
When a quote is one number on one line, it is not a quote, it is a sales pitch. Ask for it broken down per window with the glass spec written out, and ask separately what happens if the lintel is gone. The firms that give you that on paper are the firms that have actually surveyed the house.
Tom Bradley, window installer
When a low quote is a red flag
Richard Tincknell, who has worked for installer Britannia Group for over 30 years, told the FMB that less reputable firms advertise impossibly low prices to get in the door and that the result is often work that needs redoing. He also flagged time-limited discounts used to pressure a signature on the day. If a price sits far under the ranges here, find the reason first. Four explain most cases.
First, it is a supply-only price dressed as fitted. GreenMatch lists a 900 x 1200mm uPVC casement at £455 excluding installation, so a per-window figure near that is missing the labour, not beating the market. Second, the specification is lower: fewer opening sashes, basic glass instead of A-rated, no trickle vents. Third, finishing work is excluded, so scaffolding, plastering, disposal and making good arrive as extras. Fourth, the installer is not registered with a competent person scheme, which means no self-certification and a building control application at your cost. The Energy Saving Trust recommends three quotes and a registered installer for exactly this reason.
Worked examples for three real properties
The tables above are per window. Here is how they add up on three common UK houses, all in A-rated uPVC casement at the £650 average, all illustrative rather than quotes. The most searched of these is the cost of double glazing a 3-bed house, and we break that one down window by window in our cost of double glazing a 3-bed house section.
A 1930s semi, 10 windows, ladder access. Ten openings at £650 is £6,500, mid-band in our £4,000 to £10,000 range and above the Energy Saving Trust's figure of around £4,800 for a set of A-rated windows on a semi. Nothing here needs scaffolding, so the quote should track the arithmetic.
A three-bed terrace with a front bay, 9 openings. Eight flat casements at £650 is £5,200. The bay prices separately from the £1,100 to £3,000 band; take £1,800 for a three-panel uPVC bay and the total is £7,000. One bay costs about what three ordinary windows do, which is the biggest surprise on terraced quotes. Our Victorian terrace page prices the sash version.
A detached house, 14 windows, first-floor scaffolding. Fourteen at £650 is £9,100. Add a week of scaffolding at around £1,000 and a 10% contingency and you are near £11,000. This is where three quotes pay for themselves, because access assumptions vary far more between installers than unit prices do.
Three more things shift the final figure: where you live, how big your home is, and the glass specification you choose, as triple glazing adds roughly 10 to 20% over A-rated double. Location is a labour effect more than a materials one: Checkatrade notes installer rates run higher in London and the South East, and on our own regional data London sits about 20% above the national average while Manchester sits about 7% below. Use the links below to drill into whole-house totals, regional differences and glass spec before you ask anyone for a quote.
Cost by House Size
Whole-house totals from a flat to a detached, with typical window counts for each.
Cost by UK Region
How London, Manchester and Birmingham compare against the national average.
Cost by Glass Spec
From single glazing to A-rated double and triple, and what each step adds.
Cost Per Window
The single-window breakdown, including supply-only versus fully fitted.
How to use these figures
Treat every number here as a guide range, not a quote. Real prices move with access, scaffolding, glass spec and installer demand. Once you have a rough total, check it against at least three written quotes, and read how to avoid being overcharged so you can spot an inflated price. If your home is older, the is it worth it guide helps you decide whether to replace now or wait, and Double Glazing Questions Answered gives the short-form version of the queries this page works through at length.
Your property type shifts the figure too. We price it for a Victorian terrace, a bungalow, a flat or apartment, a new build, a listed building and a conservation area home.
Frequently asked questions
A standard uPVC casement runs £400 to £1,000 fully fitted, with around £650 the figure most homes land on. Aluminium adds roughly 30 to 40% and timber roughly 60 to 110%. Style matters as much as material: a sash, a bay or a bow is more work to make and fit than a flat casement, so each moves up its own band.
An average semi-detached house comes in at £4,000 to £10,000 for all windows in uPVC. The Energy Saving Trust puts a set of A-rated windows for a semi at around £4,800, and Checkatrade quotes £8,000 to £15,000 for a three-bed on 8 to 12 windows, so the honest answer is a wide band that depends on window count, style and access rather than bedroom count.
A complete quote covers removal of the old windows, supply and fit of the new ones, standard glazing and window furniture, labour, basic making good around the frames, waste disposal, VAT and the FENSA or CERTASS certificate. Scaffolding, plaster repairs, redecorating, upgraded glass and lintel or structural work are frequently excluded, so ask for each one in writing.
Because they sample different installers and different bases. On a 1200 x 1200mm timber casement Checkatrade publishes £900 to £1,500 fitted while the FMB publishes £1,975, more than double at the low end. GreenMatch quotes unit prices that exclude installation altogether. Any single guide read on its own can therefore look very different from the mainstream price, which is why we cross-check several.
The Energy Saving Trust puts the saving from replacing an entirely single-glazed semi with A-rated double glazing at around £85 a year in Great Britain and £140 a year in Northern Ireland, alongside a cut of 290kg of CO2 a year in GB and 550kg in NI. If you already have older double glazing, the saving from replacing it is much smaller and comfort, condensation and noise are the stronger reasons.
Checkatrade puts a single window at a few hours and a typical three-bed house at two to four days, with larger or more awkward properties taking longer. Installers usually work room by room, so expect noise and dust while old frames come out.
Last updated 29 July 2026. Written by Tom Bradley, a window installer with over 20 years fitting windows. Read our methodology.