Cardiff sits in the cheapest region in the UK for double glazing. Our analysis of 2026 regional data puts Wales around 13% below the UK average, the largest discount of any region, which works out at roughly £350-£870 per window fitted and £3,480-£8,700 for a typical 3-bed. That position comes from one modelled study (ExpertSure 2026) covering Wales as a whole rather than Cardiff specifically, so treat it as an approximate guide. The national detail sits on our cost by house size guide and the cost by UK region table.
How Cardiff compares with the national average
The national, fully fitted baseline is a uPVC casement at £400 to £1,000 per window and a mid-terrace or 3-bed at £4,000 to £10,000. Applying the Welsh adjustment of -13%gives the Cardiff figures below. ExpertSure's own modelled Welsh numbers are a single point rather than a range, at £415 per window and £4,350 for a full house, which sits inside the band the adjustment produces.
| Measure | UK national | Cardiff (-13%) |
|---|---|---|
| Per window (fitted casement) | £400–£1,000 | £350-£870 |
| Typical 3-bed | £4,000–£10,000 | £3,480-£8,700 |
| Modelled adjustment | Baseline | -13% |
National figures from the DGCC 2026 dataset. Welsh adjustment modelled (ExpertSure 2026) and applied to the national range; presented as an approximate guide.
What each window style costs in Cardiff
The figures above are for a standard casement, which is the most common window in UK homes. Style moves the price more than anything else except frame material: a sash costs about half as much again as a casement, and a bay is priced per bay rather than per window. Here is the full range at Cardiff prices.
| Window style | UK national | Cardiff (-13%) | Best for |
|---|---|---|---|
| Casement | £400–£1,000 | £350–£870 | The default for most UK homes |
| Sash | £600–£1,500 | £520–£1,310 | Period and conservation properties |
| Tilt & Turn | £500–£1,200 | £440–£1,040 | Flats and upper floors |
| Bay | £1,100–£3,000 | £960–£2,610 | Priced per bay, not per window |
| Fixed | £220–£440 | £190–£380 | Non-opening, the cheapest option |
National figures from the DGCC 2026 price table. Cardiff column is the national figure adjusted by -13%, the modelled Wales position (ExpertSure 2026), rounded to £10. Bay windows are priced per bay.
Three worked examples by house type
These apply the Welsh adjustment to the national house-size figures. They are illustrative, not quotes.
Flat (around 4 windows)
A national flat runs about £1,800 to £5,000 fully fitted. At -13% that points to roughly £1,570 to £4,350 in Cardiff, with floor level and access the main variables.
Mid-terrace or 3-bed (around 8 to 10 windows)
The headline Cardiff 3-bed figure is roughly £3,480-£8,700 for standard uPVC. Cardiff has a large stock of Victorian and Edwardian terraces, particularly in Canton, Roath and Grangetown, where bay windows push the total towards the upper end of that band.
Semi-detached (around 10 to 12 windows)
A national semi sits at £5,000 to £12,000. At -13% that points to roughly £4,350 to £10,440, with window count and specification moving the final price within the range.
Wales being the cheapest region does not mean every Cardiff quote is cheap. It means the going rate is lower, so a quote that lands on the national average is already above the local market. Use the Welsh figure as your anchor, not the UK one.
Tom Bradley, window installer
Grants for double glazing in Wales
Welsh funding works differently from England's, and this is the part most quote comparisons skip. The Welsh Government Warm Homes programme, delivered as Nest, is the main devolved route, but it leans towards insulation and heating measures, so glazing is not guaranteed. ECO4runs UK-wide until 31 December 2026 with no successor scheme announced. England's Warm Homes: Local Grant does not apply in Wales. Check eligibility on the grants hub before assuming any of the work will be funded.
Conservation areas and listed buildings
Cardiff has a substantial conservation footprint, and conservation-area density is the single strongest driver of regional cost variation in the research. Where conservation or listed status applies you may be required to fit timber or heritage-style frames rather than standard uPVC, with planning consent sometimes needed. A timber casement runs £760 to £1,900 per windownationally, so confirm your property's planning status with Cardiff Council before ordering.
Getting an accurate Cardiff price
Because the Welsh figure rests on one modelled source and covers the whole country rather than the city, use it as a sense-check and then get at least three written quotes from FENSA-registered installers. For context on the spread, prices in London run around 20% above the national average, while Liverpool sits about 7% below it, and the full set of city pages is on the Double Glazing Costs by UK Region hub. To price the windows themselves, the uPVC window price calculator gives a per-window estimate you can adjust down by 13%.
Get quotes from Cardiff installers
The figures above are a benchmark. For prices on your actual windows, tell us what you need and Leads 2 Trade will arrange quotes from installers covering Cardiff.
Frequently asked questions
Our analysis of 2026 regional data puts Wales around 13% below the UK average, which works out at roughly £350 to £870 per window fitted in Cardiff and £3,480 to £8,700 for a typical 3-bed. Wales is the cheapest region in that dataset. The figures come from a single modelled study, so treat them as a guide and get three local quotes.
On the 2026 modelled data, yes. Wales carries the largest discount of any UK region at about 13% below the national average, against London at roughly 20% above it. On a per-window basis that is a gap of about £155 between the two, and around £1,650 across a full house.
Welsh schemes work differently from England's. The Welsh Government Warm Homes programme, delivered as Nest, is the main route, and it leans towards insulation and heating rather than glazing, so windows are not guaranteed. ECO4 also runs UK-wide until 31 December 2026. Check eligibility before assuming any glazing work will be funded.
They can. Where a conservation area or listed status applies you may be required to fit timber or heritage-style frames instead of standard uPVC, and planning consent is sometimes needed. A timber casement runs £760 to £1,900 per window nationally, well above uPVC, so confirm your property's planning status with Cardiff Council before ordering.
No. The regional position comes from one modelled 2026 study covering Wales as a whole rather than a survey of Cardiff quotes, so we present it as a guide rather than a precise price. Get at least three written quotes from FENSA-registered installers before committing.