(A) The lawful use of a building existing at the time of the adoption of this chapter may be continued, although such use does not conform with the provisions hereof, and such use may be extended throughout those parts of the building which were manifestly arranged or designed therefor; provided, no structural alterations, except those required by law or ordinance are made therein. If no structural alterations are made, a nonconforming use of a building may be changed to another nonconforming use of the same or more restricted classification. The foregoing provisions shall also apply to nonconforming uses in districts hereafter changed. Whenever a nonconforming use of a building has been changed to a more restricted use or to a conforming use, such use shall not thereafter be changed to a less restricted use.
(B) No building which has been damaged by fire, explosion, act of God, or the public enemy to the extent of more than 60% of its value, shall be restored except in conformity with the regulations of this chapter.
(C) Except as provided in § 32.18, all nonconforming commercial or industrial buildings located within any dwelling district shall be removed or converted, and the building thereafter devoted to a use permitted in the district, in accordance with the following schedule:
(1) In the case of buildings erected before January 1, 1928, on or before January 1, 1968;
(2) In the case of buildings erected between January 1, 1928 and January 1, 1933, on or before January 1, 1973;
(3) In the case of buildings erected between January 1, 1933 and January 1, 1938, on or before January 1, 1978; and
(4) In the case of buildings erected since January 1, 1938, within 40 years from the date of such erection, but in all cases on or before January 1, 1990.
(Prior Code, § 5-10-3)