Any nonconforming use or structure existing at the time of the passage of this chapter may be continued upon the lot or in the structure so occupied, subject to the provisions of this section.

A nonconforming use shall be adjudged abandoned when there occurs a cessation of any such use or activity by an apparent act or failure to act on the part of the tenant or owner to reinstate such use within a period of one year from the date of cessation or discontinuance. Whenever a nonconforming use is abandoned, such use shall not be resumed and all further use of the structure or premises, or both, from which such nonconforming use has been discontinued shall be in accordance with the provisions of this chapter relating to the zone in which the structure or premises is located.

If a nonconforming building or use is subsequently changed to a conforming building or use, it shall not be changed back again to a nonconforming use. Any nonconforming building or use may be restored or repaired in the event of partial destruction thereof, provided that such restoration or repair be completed within a reasonable period of time from the time of such partial destruction.