R (Hand) -v- Secretary of State for Communities and Local Government [2014] EWHC 314 (Admin), 23 January 2014
Town and County Planning Act 1990 Section 171 B (3) states that enforcement action can be taken against the use of land in general within 10 years from the use commencing. However, use of a building as a dwellinghouse becomes immune from enforcement and, therefore, lawful after 4 years.