Section 20 Permission to retain buildings or works or continue use of land
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—
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
the application is for permission to retain the buildings or works, or continue the use of the land, without complying with some condition subject to which a previous planning permission was granted.
Any power to grant planning permission to develop land under this Act 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 the preceding subsection; and references in this Act to planning permission to develop land or to carry out any development of land, and to applications for such permission, shall be construed accordingly:
Provided that this subsection shall not affect the construction of section fifteen, of subsection (2) of section seventeen or of Part VI of this Act.
Any planning permission granted in accordance with the last preceding subsection 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.