(A) Nonconforming uses. Any use legally occupying an existing building at the time Ordinance No. 688 of this city became effective may be continued, but shall not be changed unless a certificate of occupancy for the new use shall have been issued by the Building Inspector after finding out that such use conforms with the provisions of this title.
(B) Land. A certificate of occupancy shall be applied for before any vacant lot is hereafter used or before an existing use of vacant land is changed, and the Building Inspector shall issue such certificate within ten days after the application is filed; provided such use is in conformity with the provisions of this title; provided, further, that no certificate of occupancy shah be required where the land is to be used for tilling the soil and growing therein farm, garden or orchard products.
(`78 Code, § 17.108.050.)