A variance once grated shall not be withdrawn or changed unless there is a change in circumstances, or if, after the expiration of one year, no substantial construction is done in accordance with the terms and conditions for which such variance was granted. The Building Commissioner shall give a notice in writing, and thirty days thereafter, the variance shall be deemed null and void. All regulations governing such premises in question shall return to those in effect before the variance was granted. (Ord. 1961-103. Passed 12-29-61.)