Pursuant to section 57 of the Town and Country Planning Act 1990 (TCPA 1990), planning permission is required for ‘the carrying out of any development of land’. TCPA 1990, s 58(1)(a) provides that planning permission may be granted by a ‘development order’. The Town and Country Planning (General Permitted Development) Order 2015 (the GPDO), SI 2015/596 is a development order for these purposes. It allows specific types of development, set out in different classes in the GPDO, SI 2015/596, Sch 2 Pt 1 to be carried out without the need to obtain planning permission. Some basement developments may constitute permitted development, depending on the facts. The enlargement, improvement or other alteration of a dwellinghouse is permitted development under GPDO, SI 2015/596, Sch 2 Pt 1, Class A, subject to exceptions