It is the purpose of this section to provide for the regulation of nonconforming uses. It is necessary and consistent with the establishment of a zoning district that all uses incompatible with permitted uses be regulated and permitted to exist only under controls:
A. Nonconforming Use Continued: The lawful use of any building or land existing at the time of the enactment of this title may be continued although such use does not conform with the provisions of this title, except as hereinafter specified.
B. Restoration Of Unsafe Structure: Any nonconforming structure or portion thereof declared unsafe by proper authority, except as provided in subsection C of this section, may be restored to safe condition.
C. Alterations: Alterations may be made to any structure or portion thereof devoted to a nonconforming use; provided, that:
1. No structural alterations are made to such structure, except those required by other law or regulation.
2. No nonconforming use is extended or enlarged.
3. A structure devoted to a nonconforming use which is declared unsafe by proper authority, destroyed or damaged in any manner or from any cause whatsoever, to the extent that the cost of restoration to the condition it was before the occurrence shall exceed fifty percent (50%) of the cost of constructing the entire structure, shall not be restored unless such structure, when restored, shall comply with the provisions of this title.
D. Substitution: The substitution of one nonconforming use for another nonconforming use is prohibited, except when authorized by the planning commission. Such substitution shall comply with the provisions of subsection C of this section.
E. Change To Conforming Use: When a nonconforming use has been changed to a conforming use, such conformity shall remain and such use shall not thereafter revert to nonconforming use.
F. Use Vacated Or Discontinued: Any nonconforming use that has vacated or has discontinued its nonconforming operations for a period of six (6) months shall not thereafter be again put to a nonconforming use.
G. Proposed Use: A proposed use that does in fact conform to the district in which it is proposed will not be permitted to commence on any parcel which does contain a nonconforming use. (1990 Code § 12-224)