39.—(1) Where permission to develop land or for the retention of development is granted under this Part, then, except as may be otherwise provided by the permission, the grant of permission shall enure for the benefit of the land and of all persons for the time being interested therein.

(2) Where permission is granted under this Part for a structure, the grant of permission may specify the purposes for which the structure may or may not be used, and in case the grant specifies use as a dwelling as a purpose for which the structure may be used, the permission may also be granted subject to a condition specifying that the use as a dwelling shall be restricted to use by persons of a particular class or description and that provision to that effect shall be embodied in an agreement under section 47.

(3) (a) Where permission to develop land is granted under this Part for a limited period only, nothing in this Part shall be construed as requiring permission to be obtained thereunder for the resumption, at the expiration of that period, of the use of the land for the purpose for which it was normally used before the permission was granted.

(b) In determining for the purposes of this subsection the purposes for which land was normally used before the grant of permission, no account shall be taken of any use of the land begun in contravention of this Part.

(4) Notwithstanding anything in this Part, permission shall not be required under this Part, in the case of land which, on 1 October, 1964, was normally used for one purpose and was also used on occasions, whether at regular intervals or not, for any other purpose, for the use of the land for that other purpose on similar occasions after 1 October, 1964.