29.—(1) An application for planning permission may relate to buildings or works constructed or carried out, or a use of land instituted, before the date of the application, whether—
(a)the buildings or works were constructed or carried out or the use instituted without planning permission or in accordance with planning permission granted for a limited period; or
(b)the application is for permission to retain the buildings or works or to continue the use of land without complying with some condition subject to which a previous planning permission was granted.
(2) Any power to grant planning permission to develop land under this Order shall include power to grant planning permission for the retention on land of buildings or works constructed or carried out, or for the continuance of a use of land instituted, as mentioned in paragraph (1); and references in this Order to planning permission to develop land or carry out any development of land, and to applications for such permission, shall be construed accordingly.
(3) Any planning permission granted under paragraph (2) may be granted so as to take effect from the date on which the buildings or works were constructed or carried out, or the use was instituted, or (in the case of buildings or works constructed or a use instituted in accordance with planning permission granted for a limited period) so as to take effect from the end of that period, as the case may be.