Understanding Planning Permission Documents: A UK Homeowner's Guide

Many smaller projects fall under "permitted development" and do not need planning permission at all, subject to size and location limits. Larger extensions, some outbuildings, a change of use, and work on a listed building or in a conservation area are more likely to need it.

Rules vary by council and by property, so check with your local planning authority before assuming a project does or does not need permission.

Planning permission and Building Regulations are approved separately, and a project can need one, both, or neither. Permission covers whether the work was allowed; Building Regulations cover whether it was built safely.

Since April 2024, councils generally have a single 10-year time limit to take enforcement action against any breach of planning control, including unauthorised building work and an unauthorised change of use. After that, the work is often described as immune from enforcement.

Older work substantially finished before April 2024 may still fall under the previous rule, which allowed only 4 years for unauthorised building work. Check with your council or a solicitor if this applies to your case.

Immunity from enforcement is not the same as formal permission. A Lawful Development Certificate from the council is the recognised way to prove work is lawful, and is often what a buyer's solicitor will ask for rather than relying on the passage of time alone.

Planning permission and any Lawful Development Certificate do not expire once the work is complete. Keeping copies with the rest of your property's record means they are ready whenever a buyer's solicitor asks for them.