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 reason 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 a way which increases its nonconformity;
B.
Should such structure be destroyed by any means, in whole or in part, it may be reconstructed in accordance with the provisions of § 305-13 below.
C.
Should such structure be moved for any reason for any distance whatever, it must thereafter conform to the regulations for the zone in which it is located after it is moved.