Any use of property existing at the time of the passage of the ordinance codified in this article that does not conform with the regulations prescribed in the preceding sections of this article shall be deemed a nonconforming use, except that any duplex or apartment use existing at the time of passage of the ordinance codified in this article shall be thereafter deemed a conforming use.

The lawful use of land existing at the time of the passage of the ordinance codified in this article, although such use does not conform to the provisions thereof, may be continued, but if said nonconforming use is discontinued for a period of time in excess of six months, any future use of said premises shall be in conformity with the provisions of this article.

The lawful use of the building at the time of the passage of the ordinance codified in this article 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 the building may be changed to another nonconforming use of the same or more restricted classification; provided, however, that in the event a nonconforming use of a building is once changed to a nonconforming use of a higher or more restricted classification, it shall not later be reverted 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.

A nonconforming use shall not be extended nor a nonconforming structure rebuilt in case of obsolescence or total destruction by fire or other cause, except that a single-family residential dwelling structure in a single-family dwelling district, partially or totally destroyed, may be rebuilt by the owner at the same size as when it was destroyed, or larger, but the owner shall not be required to build to a minimum house size greater than the size of the destroyed house, even if required by the area regulations of the zoning district in which the property is situated. In case of partial destruction by fire or other cause of a nonresidential structure, not exceeding 50 percent of the value, the building inspector shall issue a permit for reconstruction. If there is greater than 50 percent and less than total destruction, the board of adjustment may grant a permit for repair of a nonresidential structure, after a public hearing and having due regard for the property and the character of the surrounding property and the conservation and preservation of property.

A violation of this article and a request for a nonconforming designation or request for relief under this designation shall not create an estoppel of the trial of any lawsuit which may be filed in any court.