Any nonconforming use, building or structure which existed lawfully on the effective date of this amendatory zoning chapter and which remains nonconforming, and any use, building or structure which shall become nonconforming upon the adoption of this subchapter or of any subsequent amendments thereto, may be continued subject to the limitations set forth in this subchapter. This subchapter shall not be construed as authorizing the continuation of any use, building or structure, which was not so lawfully existing. The provisions hereof shall not only apply to a building or structure which is completely occupied by the nonconforming use, but shall also apply to one in which the nonconforming use occupies only a portion of the building or structure.
(1980 Code, § 29.801)