Where a lawful structure exists at the effective date of adoption or amendment of this chapter that could not be built under the terms of this chapter by reasons of restrictions on area, lot, coverage, height, yards or other characteristics of the structure or its location on the lot, such structure may be continued so long as it remains otherwise lawful, subject to the following provisions:
A. No such structure may be enlarged or altered in any way which increases its nonconformity, unless an enlargement or structural alteration makes the building more conforming or is required by law.
B. Should such structure be destroyed by any means to an extent of more than 50% of its replacement cost at time of destruction, it shall not be reconstructed except in conformity with the provisions of this chapter.
C. Should such structure be moved for any reason for any distance whatsoever, it shall thereafter conform to the regulations for the district in which it is located after it is moved.
D. Structural alterations may be permitted if necessary to adapt a nonconforming building to new technologies or equipment pertaining to uses housed in such building. Any enlargement necessary to adapt to new technologies shall be authorized only by a variance.