London build costs run at 130% of the UK national average, across councils including City of Westminster, Camden, Hackney. A 20m² example at mid-range spec: £96,665–£130,783. Adjust the size and spec below for your project.
England only. Takes about a minute.
| Size | Basic | Mid-range | Premium |
|---|---|---|---|
| 15m² | £50,347–£68,116 | £72,499–£98,087 | £103,826–£140,470 |
| 20m² | £67,129–£90,821 | £96,665–£130,783 | £138,434–£187,294 |
| 30m² | £100,693–£136,232 | £144,998–£196,174 | £207,652–£280,940 |
Each council sets its own fees and decision times. See your council’s page for the exact figures.
Cost bands refreshed quarterly from published 2026 UK cost guides.