(1)In this Act, except where the context otherwise requires, "development", subject to the following provisions of this section, 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 qt 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, that is to say—
(a)the carrying out of works for the maintenance, improvement or other alteration of any building, being works which affect only the interior of the building or which do not materially affect the external appearance of the building and (in either case) 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 therein below ground ;
(b)the carrying out by a local highway authority of any works required for the maintenance or improvement of a road, being works carried out on land within the boundaries 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 thereof 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 thereof which is so used;
(b)the deposit of refuse or waste materials on land involves a material change in the use thereof, notwithstanding that the land is comprised in a site already used for that purpose, if either the superficial area of the deposit is thereby extended, or the height of the deposit is thereby extended and exceeds the level of the land adjoining the site.
(4)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.
(5)In this Act " new development" means any development other than development of a class specified in Part I or Part II of Schedule 8 to this Act; and the provisions of Part III of that Schedule shall have effect for the purposes of Parts I and II thereof.