Plan Then Build

Rear extension cost in Yorkshire and the Humber

Yorkshire and the Humber build costs run at 90% of the UK national average, across councils including Leeds, Sheffield, York. A 20m² example at mid-range spec: £66,922–£90,542. Adjust the size and spec below for your project.

Permitted Development & Cost Checker

England only. Takes about a minute.

Rear extension cost by size and spec in Yorkshire and the Humber

SizeBasicMid-rangePremium
15£34,855–£47,157£50,192–£67,906£71,879–£97,249
20£46,474–£62,876£66,922–£90,542£95,839–£129,665
30£69,711–£94,314£100,383–£135,813£143,759–£194,497

Does a rear extension need planning permission?

Council planning fees in Yorkshire and the Humber

Each council sets its own fees and decision times. See your council’s page for the exact figures.

Rear extension cost in other regions

Cost bands refreshed quarterly from published 2026 UK cost guides.