Extensions cost in Cardiff
2026 prices for South Glamorgan · Wales
Extensions in Cardiff typically costs between £27,500 and £110,500, with most homeowners landing near £69,000. Local pricing sits about 8% below the UK average. Low day rates, though rural travel surcharges and solid-wall properties can offset the saving on larger jobs.
£27,500 – £110,500
UK average £2,200 per m² · Cardiff index 92
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Extensions prices in Cardiff by finish level
| FINISH LEVEL | CARDIFF COST | WHAT'S INCLUDED |
|---|---|---|
| Budget | £27,500 – £41,500 | Entry-level materials, existing layout retained |
| Mid-range | £40,000 – £60,000 | Better fittings, some layout change |
| Premium | £54,000 – £80,500 | High-specification materials and full redesign |
£37,950
About 55% of a typical Cardiff job, at Wales day rates.
£31,050
Materials pricing is broadly national — this is where specification, not location, drives your total.
What affects extensions cost in Cardiff
Large Victorian terrace belt in Cathays, Roath and Canton, much of it student-let. Welsh building regulations differ from England on some energy and ventilation requirements.
- Drainage runs needing diversion
- Party wall agreements with neighbours
- Poor ground conditions requiring deeper foundations
Rules in Cardiff
Building control and planning applications for extensions work in Cardiff go through Cardiff Council. Confirm before booking whether your property sits in a conservation area, is listed, or is covered by an Article 4 direction — each removes permitted development rights and changes the approval route.
Serving CF10, CF11, CF14, CF24 and the surrounding South Glamorgan area.
Find vetted trades near CardiffExtensions in Cardiff: common questions
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