Where a lawful structure exists at the effective date of adoption or amendment of this Part that could not be built under the terms of this Part by reason of restrictions on area, lot coverage, height, yards, its location on the lot, bulk or other requirements concerning the structure, the structure may be continued so long as it remains otherwise lawful, subject to the following provisions:
(a) No such non-conforming structure may be enlarged or altered in a way which increases its non-conformity, but any structure or portion may be altered to decrease its non-conformity;
(b) Should the non-conforming structure or a non-conforming portion of structure be damaged by more than 50% of its fair market value by fire or an act of God, it may, only after approval by the Building and Zoning Appeals Board be reconstructed as it previously existed. All remaining debris shall be cleared away and disposed of properly within two months of the time of destruction. If the structure is damaged 50% or less of the fair market value, the non-conforming structure may be restored on the same footprint, provided such restoration shall begin within six months from the time of damage.
(c) Should the structure be moved for any reason for any distance whatever, it shall thereafter conform to the regulations for the district in which it is located after it is moved.