Plotline
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 a single-storey rear extension is measured

What do you want to do?
New floor area
Approximate added floor space (m²).
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.