Building prices in Sussex
Building costs vary a great deal with the project, the specification and the site. The figures below are UK guide prices from the named sources, as no national guide publishes Sussex prices. Use them to set a rough budget, then get detailed quotes before committing to any work.
Extension prices
- Single storey extension, per m²Source: Less.co.uk£1,500 to £2,500
- Single storey extension, South East, per m² (mid range)Source: Less.co.uk£1,900 to £2,900
- Double storey extension, per m²Source: Less.co.uk£1,200 to £2,000
- Small single storey extension (20m²)Source: MyJobQuote£20,000 to £44,000
- Medium single storey extension (30m²)Source: MyJobQuote£30,000 to £66,000
Loft conversion prices
- Velux loft conversion (30m²)Source: Checkatrade£22,500 to £30,000
- Dormer loft conversion (30m²)Source: Checkatrade£40,000 to £60,000
- Hip to gable conversion (30m²)Source: Checkatrade£50,000 to £70,000
- Mansard loft conversion (30m²)Source: Checkatrade£50,000 to £80,000
Other building work prices
- Garage conversionSource: Checkatrade£10,000 to £20,000
- New kitchen (as part of a renovation)Source: Checkatrade£7,000 to £25,000
- BathroomSource: MyBuilder£2,500 to £12,000
- Knocking down wallsSource: Checkatrade£500 to £3,500
- Householder planning application in England (from 1 April 2026)Source: GOV.UK£548
What affects building prices?
- Specification: Higher quality materials and finishes cost more, and fitted kitchens, bathrooms and glazing can move the total a long way.
- Access: Difficult access increases labour and delivery costs. Less.co.uk says restricted access adds 5 to 10% to an extension.
- Structural work: Foundations, underpinning and steelwork add cost. Less.co.uk says difficult ground can add £2,000 to £8,000.
- Location: Less.co.uk puts mid range single storey extension costs in the South East 17% above its national average.
- Existing conditions: Older properties often reveal problems once work starts, so most guides advise keeping a contingency.
Frequently asked questions
Why are there no Sussex building prices?+
No national cost guide publishes Sussex prices, so the figures on this page are UK and South East guide prices copied from the named sources. Use them to set a rough budget, then get detailed quotes.
Do building costs run higher in the South East?+
Less.co.uk's 2026 guide puts mid range single storey extension costs in the South East 17% above its national average, at £1,900 to £2,900 per m² compared with a national figure of £1,500 to £2,500 per m².
What is not included in these prices?+
Less.co.uk says its per m² figures exclude VAT, professional fees and interior fit out. Planning fees, building control charges, architect or technologist fees and structural engineer fees are usually extra, and building control charges vary by council.
How much does a medium single storey extension cost?+
MyJobQuote puts a medium single storey extension of 30m² at £30,000 to £66,000, and a small one of 20m² at £20,000 to £44,000.
How much does it cost to knock down a wall?+
Checkatrade gives £500 to £3,500 for knocking down walls. Foundations, underpinning and steelwork all add cost, so get a detailed quote for your own house.
About these figures
Each figure is copied from the source named beside it, and the sources measure different things, so the ranges are not directly comparable with each other. Less.co.uk says its per m² figures exclude VAT, professional fees and interior fit out. The Checkatrade loft figures are for a 30m² conversion. Planning fees, building control charges, architect or technologist fees and structural engineer fees are usually extra, and building control charges vary by council. For more detail, see our single storey extension cost guide, loft conversion cost guide and extension cost calculator.
Sources for the prices on this page
- Less.co.uk: House extension cost per m² in 2026, checked October 2026
- MyJobQuote: How much does a single storey extension cost in the UK?, checked October 2026
- Checkatrade: Loft conversion cost 2026 UK price guide, checked October 2026
- Checkatrade: Garage conversion cost in the UK in 2026, checked October 2026
- Checkatrade: House renovation cost breakdown 2026, checked October 2026
- MyBuilder: How much does a house renovation cost?, checked October 2026
- GOV.UK: Fees for planning applications in England from 1 April 2026, checked October 2026
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