If a use, building or structure becomes subject to this subchapter, whether by the extension of the zoning jurisdiction of the city by reason of extension of the corporate of the city, or otherwise, and the use, building or land at the time it becomes subject to this subchapter is lawful but does not conform with the regulations of the district in which the use, building or structure is situated, the use, building or structure may continue as a nonconforming use, building or structure under the provisions hereof.
(1980 Code, § 29.801)