Any use of property existing at the time of the passage of this ordinance that does not conform to the regulations prescribed in the preceding sections of this ordinance shall be deemed a nonconforming use; except that any duplex or apartment use existing at the time of the passage of this ordinance shall be thereafter deemed a conforming use. Any lawful use existing within a building at the time of the passage of this ordinance, in any business, industrial or manufacturing district, shall be deemed a conforming use upon the lot devoted to such use at the time of the passage of this ordinance.

The lawful use of land existing at the time of the passage of this ordinance, although such does not conform to the provision hereof, may be continued, but if such nonconforming use is discontinued, any future use of said premises shall be in conformity with the provisions of this ordinance. If a building occupied by a nonconforming use is destroyed by fire or the elements it may not be reconstructed or rebuilt except to conform with the provisions of this ordinance.

The lawful use of the building at the time of the passage of this ordinance may be continued, although such does not conform to the provisions hereof, and such use may be extended throughout the building provided no structural alteration, except those required by law or ordinance, are made therein. If no structural alterations are made, a nonconforming use of a building is once changed to a nonconforming use of a higher or more restricted classification it shall not later revert to the former lower or less restricted classification.

The right of nonconforming use to continue shall be subject to such regulations as to maintenance of the premises and conditions of operation as may in the judgment of the board of adjustment be reasonably required for the protection of adjacent property.

Nothing in this ordinance shall be taken to prevent restoration of a building destroyed to the extent of not more than fifty-one (51) percent of its reasonable value by fire, explosion or other casualty, or act of God, or a public enemy, nor the continued occupancy or use of such building, or part thereof, which existed at the time of such partial destruction.