Except as otherwise provided herein, any lawfully established
use of a building or land existing at the time of the enactment of
this chapter, or amendments thereto, may be continued although such
use does not conform with the provisions of this chapter.
Maintenance and extension of a nonconforming structure are permitted,
however, no substantial improvements may be made during the life of
the structure.
No building damaged by fire or other causes to the extent of
more than 75% of its true or full value, as computed through the use
of equalization rates current at the time, shall be repaired or rebuilt
except in conformity with the regulation of this chapter.
Whenever the boundaries of a district shall be changed so as
to transfer an area from one district to another district of a different
classification, the foregoing provisions shall also apply to any nonconforming
uses existing therein.