Free Tool
Extension & Renovation Cost Estimator
Get a ballpark UK build cost in seconds, adjusted for your region, project size and specification level.
5m²200m²
Good quality mid-range spec
Estimated total project cost
£62,112 — £76,512
UK average pricing (0% vs UK average) · £2,100–£2,700 per m²
What's included
Build cost (mid-range)£48,000
Professional fees (~12%)£5,760
Contingency (10%)£4,800
VAT (20%)£10,752
Ballpark guide only, based on typical 2026 UK build rates. Actual costs vary with site conditions, access, ground works and market conditions. For accurate drawings and costed designs, request a free quote.