Subject to the provisions of this article, the use of buildings or land existing at the time of enactment of this section may be continued even though such use does not conform with the provisions of this Planning and Zoning Code for the district in which such land is located; however, no enlargement or expansion of such nonconforming unit shall be permitted. No building may be constructed or structure altered or enlarged or extended so as to increase the floor space unless the use thereof is changed to the use conforming with the requirements of this Planning and Zoning Code. Nothing herein contained shall however, prevent the reconstruction or replacement of a building wholly or partially destroyed by fire, explosion, acts of God or public enemy or prevent the restoration of a wall deemed unsafe or defective and any building which has been so used may be replaced with a new building having similar facilities and occupying the same space and area, provided however, any replacement or restoration shall conform to the requirements of the Building Code of the State and the City.
(1960 Code 7-307)