(1)Subject to the following provisions of this section, in this Act, except where the context otherwise requires, “development,” means the carrying out of building, engineering, mining or other operations in, on, over or under land, or the making of any material change in the use of any buildings or other land.
(2)The following operations or uses of land shall not be taken for the purposes of this Act to involve development of the land—
(a)the carrying out for the maintenance, improvement or other alteration of any building of works which—
(i)affect only the interior of the building, or
(ii)do not materially affect the external appearance of the building,
and are not works for making good war damage or works begun after 5th December 1968 for the alteration of a building by providing additional space in it underground;
(b)the carrying out on land within the boundaries of a road by a local highway authority of any works required for the maintenance or improvement of the road;
(c)the carrying out by a local authority or statutory undertakers of any works for the purpose of inspecting, repairing or renewing any sewers, mains, pipes, cables or other apparatus, including the breaking open of any street or other land for that purpose;
(d)the use of any buildings or other land within the curtilage of a dwellinghouse for any purpose incidental to the enjoyment of the dwellinghouse as such;
(e)the use of any land for the purposes of agriculture or forestry (including afforestation) and the use for any of those purposes of any building occupied together with land so used;
(f)in the case of buildings or other land which are used for a purpose of any class specified in an order made by the Secretary of State under this section, the use of the buildings or other land or, subject to the provisions of the order, of any part of the buildings or the other land, for any other purpose of the same class.
(3)For the avoidance of doubt it is hereby declared that for the purposes of this section—
(a)the use as two or more separate dwellinghouses of any building previously used as a single dwellinghouse involves a material change in the use of the building and of each part of it which is so used;
(b)the deposit of refuse or waste materials on land involves a material change in its use, notwithstanding that the land is comprised in a site already used for that purpose, if—
(i)the superficial area of the deposit is extended, or
(ii)the height of the deposit is extended and exceeds the level of the land adjoining the site.
(4)For the purposes of this Act mining operations include—
(a)the removal of material of any description—
(i)from a mineral-working deposit;
(ii)from a deposit of pulverised fuel ash or other furnace ash or clinker; or
(iii)from a deposit of iron, steel or other metallic slags; and
(b)the extraction of minerals from a disused railway embankment.
(5)Without prejudice to any regulations made under the provisions of this Act relating to the control of advertisements, the use for the display of advertisements of any external part of a building which is not normally used for that purpose shall be treated for the purposes of this section as involving a material change in the use of that part of the building.
(6)In this Act “new development” means any development other than development of a class specified in Part I or Part II of Schedule 3; and Part III of that Schedule has effect for the purposes of Parts I and II.