A lawfully existing residential building which contains no nonconforming use, but which does not comply with the applicable lot size requirements, building bulk limitations or off-street parking requirements may be continued so long as it remains otherwise lawful. Such buildings shall be referred to in this article as "nonconforming residential buildings" and shall be subject to the following regulations:
(a) Enlargement; Repair; Alterations. A nonconforming residential building may be enlarged, maintained, repaired or structurally altered; provided, that no such enlargement, maintenance, repair or structural alteration shall either create any additional nonconformity or increase the degree of the existing nonconformity of all or any part of such building; and provided further, that damaged or destroyed buildings shall be subject to the restrictions in subsection (b) hereof.
(b) Reconstruction. In the event a nonconforming residential structure is destroyed by fire, flood or other natural causes, such residences may be rebuilt on the same foundation with the previously existing yard space; provided, that the residence is in the process of reconstruction within twelve months of the date it was destroyed.
(c) Damage or Destruction. In the event a nonconforming residential building is damaged or destroyed by means other than as described in subsection (b) hereof, to such an extent that the cost of restoring it to its condition prior to such damage or destruction exceeds fifty percent (50%) of the current replacement cost of the entire building, exclusive of foundations, such building shall not be restored unless it shall thereafter conform to the regulations for the district in which it is located.
(d) Moving. No nonconforming residential building shall be moved, in whole or in part, for any distance whatever, to any other location on the same or any other lot unless the entire building shall thereafter conform to the regulations of the district in which it is located after being moved.
(1970 Code Sec. 32-77)