Any permit issued shall become invalid unless the work authorized by it shall have been commenced within 90 days after its issuance, or if the work authorized by such permit is suspended or abandoned for a period of 6 months after the time the work is commenced; provided that, for cause, one or more extensions of time, for periods not exceeding 90 days each, may be approved by the Building Commissioner. (Ord. 68-97. Passed 4-20-1998.)