Except as otherwise provided in this Title, and subject to the specific provisions of this Chapter, nonconforming structures and nonconforming uses of land or structures which are lawfully existing, or for which building permits had been issued on or before the effective date either of the ordinance codified in this Title or any amendment of this Chapter may be constructed and/or continued, even though the particular structure or use does not conform to the regulations for the zone in which it is located; provided, however, that except as otherwise provided in this Chapter no nonconforming use may be extended to occupy a greater or different area of land or structure than is occupied at the time it first became nonconforming. Routine maintenance and repairs may be performed on a structure or site, the use or structure thereon being nonconforming. (Ord. 89-1 § 1, 1989.)