Plan Then Build

Two-storey extension cost in North West

North West build costs run at 93% of the UK national average, across councils including Manchester, Liverpool, Salford. A 20m² example at mid-range spec: £69,153–£93,560. Adjust the size and spec below for your project.

Permitted Development & Cost Checker

England only. Takes about a minute.

Two-storey extension cost by size and spec in North West

SizeBasicMid-rangePremium
15£36,017–£48,729£51,865–£70,170£74,275–£100,490
20£48,023–£64,972£69,153–£93,560£99,034–£133,987
30£72,034–£97,458£103,729–£140,340£148,551–£200,980

Does a two-storey extension need planning permission?

Council planning fees in North West

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

Two-storey extension cost in other regions

Cost bands refreshed quarterly from published 2026 UK cost guides.