This tool provides a ballpark estimate for home extensions and loft conversions based on current UK market rates. Answer four questions about project type, size, specification, and region to receive a cost range.
Select any features you plan to include
Complete steps 1–4 on the left to generate your instant ballpark estimate.
This calculator uses our live pricing database and regional cost factors to produce a realistic ballpark range. Actual costs depend on site conditions, contractor availability, and your final specification. We recommend using this as a starting point, then getting a formal estimate.
Labour and material costs vary significantly across the UK. London and the South East typically cost 15–25% more than the Midlands baseline. The North of England and Scotland/Wales are generally 8–10% lower. Our calculator applies these regional factors automatically.
Once you have a ballpark figure, the next step is a formal estimate based on your actual drawings and specification. We turn these around within 24 hours, using cost data updated daily for the most accurate estimates. Fees start from £200 + VAT.
Send us your drawings and we'll produce a detailed cost plan within 24 hours. No obligation, fees from £200 + VAT.