If a lawful use involving individual structures, or of a structure and land in combination, exists at the effective date of adoption or amendment of this Part that would not be allowed in the district under the terms of this Part, the lawful use may be continued so long as it remains otherwise lawful, subject to the following provisions:
(a) No existing structure devoted to a use not permitted by this Part in the district in which it is located shall be enlarged, extended, constructed, reconstructed, moved or structurally altered except in changing the use of the structure to a use permitted in the district in which it is located;
(b) Any non-conforming use may be extended throughout any parts of a building which were manifestly arranged or designed for the use at the time of adoption or amendment of this Part, but no such use shall be extended to occupy any land outside the building;
(c) If no structural alterations are made, any non-conforming use of a structure or structure and land, may, upon appeal to the Building and Zoning Appeals Board, be changed to another non-conforming use provided that the Building and Zoning Appeals Board finds that the proposed use is equally appropriate or more appropriate to the district than the existing non-conforming use. In permitting the change, the Building and Zoning Board may require appropriate conditions and safeguards in accord with other provisions of this Part;
(d) Any structure, or structures and land in combination, in or on which a non- conforming use is superseded by a permitted use, shall thereafter conform to the regulations for the district, and the non-conforming use may not thereafter be resumed;
(e) When a non-conforming use of a structure, or structure and land in combination is discontinued or abandoned for more than one (1) year, except when government action impedes access to the premises, the structure or structure and land in combination shall not thereafter be used except in conformity with the regulations of the district in which it is located;
(f) Where non-conforming use status applies to a structure and land in combination, removal or destruction of the structure shall eliminate the non-conforming status of the land.