Do you need planning permission?
Answer at most seven questions and see whether your extension, side return or loft conversion likely falls under permitted development in England. An indication with sources, never a guarantee; the council always has the last word.
Question 1 of at most 7
What are you planning?
Know where you stand? Then get the numbers: the free cost calculator prices your extension or loft in seconds, no email required.
Frequently asked questions
What is permitted development?
A national set of rights in England that lets you extend or convert within fixed limits without a planning application: roughly 3 to 4 m deep for a single-storey rear extension, 40 to 50 cubic metres for a loft, always with exceptions for flats, listed buildings and designated land. Outside the limits you apply for planning permission.
Is planning permission the same as building regulations?
No, and this is the most common mix-up. Planning permission is about whether you may build it; building regulations are about how it is built (structure, fire safety, insulation, electrics, drainage) and apply to almost all of this work even when no planning permission is needed.
How do I get certainty before I build?
Ask your local planning authority, or apply for a Lawful Development Certificate: a formal council document confirming your project is lawful without planning permission. Useful when you sell the house too.
Does this check cover Scotland, Wales and Northern Ireland?
No. Planning is devolved and the rules differ; this check follows the English permitted development limits. The official guidance for each nation is linked from planningportal.co.uk.