Where a lawful structure exists at the effective date of adoption of this ordinance that could not be built under the terms of this ordinance by reason of restrictions on area, lot coverage, height, yards, its location on the lot, or other requirements concerning the structure, that structure may be continued as long as it remains otherwise lawful, subject to the following provisions:
(A) No such nonconforming structure may be enlarged or altered in a way which increases its nonconformity, except that the extension of any established nonconforming setback building line (such as foundation wall, parking lot edge), does not violate the intent of this provision even though the extension may result in the addition of structure or parking lot square footage; and
(B) Any nonconforming structure or portion thereof may be altered to decrease its nonconformity.
(C) If any such nonconforming structure ceases being used for any reason for a period of more than 6 months, any subsequent use of the structure shall conform to the regulations specified by this ordinance for the district in which the structure is located.