A use or structure lawfully in existence at the effective date of this chapter which is thereby made nonconforming or a lawful prior nonconforming use or structure may be continued as provided for in this chapter.

No nonconforming use or structure shall be enlarged, extended, reconstructed, substituted or structurally altered except when such changes are in conformity with this chapter or when required to do so by law. Normal maintenance and repair of a nonconforming structure or use is permitted, provided that it does not extend or expand the degree of nonconformity.

Any nonconforming use or structure which is less than fifty-percent destroyed by fire, casualty or act of God may be repaired, rebuilt and used as before, provided that no increase in the degree of nonconformity is thereby created. All repairs shall be commenced within two years after the damage occurs and shall be completed within four years after such date, or such use shall not be rebuilt except as a conforming use or structure.

Cessation of a nonconforming use for a continuous period of two years shall create a rebuttable presumption that such use has been abandoned. Such nonconforming use shall not thereafter be revived.

Lots in R-300 and R-100 Zones which were conforming at the time they were created will be considered conforming lots if the lots meet the current yard and setback requirements of the zone in which the lots are located.