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Feasibility & value · England & Wales

Put in a postcode and the change you're considering. You'll get whether it's likely permitted, a build-cost range, the value it could add, and whether the numbers stack up — before you pay anyone for drawings.

How an extension is measured
EAVESextension must notrise above this line RIDGEhighest point of roof max 4 m high REAR PROJECTIONmax 3 m (terraced) / 4 m (detached)measured from the original rear wall original rear wall

The rear projection is measured from the original rear wall — not from any existing extension. The new roof must not rise above the eaves (where the main roof meets the wall).

What do you want to do?
Confirm anything that applies to the property:

Indicative only. This is a screening tool, not planning advice or a formal valuation. Permitted-development rules carry conditions a screen can't see (height, boundaries, prior extensions, Article 2(3) land). Confirm with the local planning authority and a RICS surveyor before committing money.