Unless otherwise specified in the action granting development plan approval, said approval which has not been utilized within a period of 12 consecutive months from the effective date shall become null and void. Also the abandonment or nonuse of a development plate approval for a period of 12 consecutive months shall terminate said development plan approval and any privileges granted thereunder shall become null and void. However, an extension of time may be granted by Commission or Council action.
('64 Code, § 73.10)