Subject to the provisions of this section, every planning permission granted or deemed to have been granted before the commencement of this section shall, if the development to which it relates has not been begun before the beginning of 1968, be deemed to have been granted subject to a condition that the development must be begun not later than the expiration of five years beginning with the said commencement.
Subject to the provisions of this section, every planning permission granted or deemed to be granted after the commencement of this section shall be granted or, as the case may be, be deemed to be granted, subject to the condition that the development to which it relates must be begun not later than the expiration of—
(a) five years begirming with the date on which the permission is granted or, as the case may be, deemed to be granted ; or
(b) such other period (whether longer or shorter) beginning with the said date as the authority concerned with the terms of the planning permission may direct, being a period which the authority consider appropriate having regard to the provisions of the development plan and to any other material considerations.
If after the commencement of this section planning permission is granted without the condition required by subsection (2) above, it shall be deemed to have been granted subject to the condition that the development to which it relates must be begun not later than the expiration of five years beginning with the date of the grant.
Nothing in this section applies—
(a) to any outline planning permission, as defined by section 66 below;
(b) to any planning permission granted by a development order;
(c) to any planning permission which was granted or deemed to be granted, before the commencement of this section, subject to an express condition that the development to which it relates should be begun, or be completed, not later than a specified date or within a specified period;
(d) to any planning permission granted for a limited period (within the meaning of section 18 of the principal Act); or
(e) to any planning permission granted under section 20 of the principal Act on an application relating to buildings or works completed, or a use of land instituted, before the date of the application.