The Town and Country Planning (General Permitted Development) Order 1995

G.1    Condition

Development is permitted by Class G subject to the condition that, on or before the expiry of the period of six months beginning with the date on which the use began, the use shall cease, and any structure shall be removed, and the land shall be restored to its condition before the development took place, or to any other condition as may be agreed in writing between the local planning authority and the developer.