Without prejudice to the generality of section 29(1) of this Act, conditions may be imposed on the grant of planning permission thereunder—
(a) for regulating the development or use of any land under the control of the applicant (whether or not it is land in respect of which the application was made) or requiring the carrying out of works on any such land, so far as appears to the local planning authority to be expedient for the purposes of or in connection with the development authorised by the permission;
(b) for requiring the removal of any buildings or works authorised by the permission, or the discontinuance of any use of land so authorised, at the end of a specified period, and the carrying out of any works required for the reinstatement of land at the end of that period.
Any planning permission granted subject to such a condition as is mentioned in subsection (1)(b) of this section is in this Act referred to as "planning permission granted for a limited period".
Where—
(a) planning permission is granted for development consisting of or including the carrying out of building or other operations subject to a condition that the operations shall be commenced not later than a time specified in the condition (not being a condition attached to the planning permission by or under section 41 or 42 of this Act); and
(b) any building or other operations are commenced after the time so specified,
the commencement and carrying out of those operations do not constitute development for which that permission was granted.