Planning enforcement time limits are set in legislation.

A four-year limit applies to ‘unauthorised operational development’ (the carrying out of building, engineering, mining or other operations in, on, over or under land) and change of use to a single dwelling house. After four years following the breach of planning control, the development becomes lawful, and no enforcement action can be taken.

A ten-year limit applies to all other development including change of use (other than to a single dwelling house) and breaches of condition. After ten years, the development becomes lawful if no enforcement action has begun. There is no limit regarding enforcement action being taken against unauthorised works on a listed building.