A common question near the border is whether it is cheaper to build in Wales than in England. The honest answer is that costs vary by region and project, not by country alone.
Figures are typical ranges and guides, not quotes.
What published guides say
Guides to UK extension costs vary. Many quote roughly £1,500–£2,500 per square metre for building work, with some giving higher figures, up to about £3,000 per m² or more for higher specifications and in the south east of England. London and the south east are usually the most expensive regions, and prices elsewhere are often lower. For a worked example, see how much a house extension costs.
What drives regional differences
- Labour rates: skilled trades cost more where demand is high
- Demand and availability: busy areas have longer waiting lists
- Access and site constraints: tight terraces and difficult access increase labour time
- Ground conditions: clay, slopes or high water tables can change foundation costs
- Specification: premium finishes add far more than regional variation
- Distance: travel and delivery for rural sites
- Regulatory requirements: drainage or environmental rules for the site
South Wales and the west of England
Costs in south Wales and the west of England often sit below London and the south east. However, two similar extensions can differ by tens of thousands of pounds depending on specification, structure and the builder, so ask for detailed quotes rather than relying on averages.
Typical project ranges
- Small single-storey (15–20 m²): roughly £25,000–£40,000 and up
- Medium (25–40 m²): roughly £40,000–£90,000
- Large or two-storey: from about £70,000
Costs people compare across the border
- Planning and building control fees differ by authority; check fees with the council
- Professional fees (design, engineers) vary by firm, not by country
- VAT applies in the same way across the UK; most extension work is standard-rated
See our guide to building in Wales vs England for differences in the rules.
How to get an accurate price
- Prepare drawings and a specification
- Get at least three itemised quotes; see how to compare builder quotes
- Check what is included, including approvals and fees
- Allow a 10–15% contingency
- Agree a contract and stage payments
Get a quote from Abron Contracting
We are based in Newport, South Wales and work on projects in Wales and England. For a clear written price, contact us or call 01633379170. See our guide to hiring a builder across the border.
Frequently asked questions
Is it cheaper to build an extension in Wales than in England?
Not automatically. Costs depend on region, specification and builder. South Wales is often cheaper than London and the south east, but individual quotes vary widely.
How much does an extension cost per square metre in Wales?
Roughly £1,500–£2,500 per m² is a common guide for building work, with higher costs for premium finishes. Get a local quote.
Do planning fees differ between Wales and England?
Fees are set nationally in each country and can differ. Check the current fee with your council.
Do I pay VAT on an extension in Wales?
Yes, most extension work on an existing home is standard-rated across the UK.
What increases extension costs most?
Size, structure, ground conditions and specification matter more than the country.
