Any permission or consent given or deemed to have been given in terms of this Part shall be revocable at the sole discretion of the local authority, and, subject to the terms of any agreement concluded in terms of section 34, the local authority may require the owner of any building from which a projection or encroachment has been constructed to remove the projection or encroachment at his own expense and within such period as the local authority may specify:

Provided that the local authority may not require a projection or encroachment to be removed within than six months unless the projection or encroachment has become a danger to persons or vehicles.