The lawful use of a building existing at the time of the adoption of this Chapter may be continued even though such use does not conform with the provisions hereof, except that nonconforming use buildings may be enlarged up to fifty percent (50%) of their building area existing on the effective date of this Chapter, or at the effective date of any subsequent amendments or changes as a result of which a building becomes nonconforming.

If no structural alterations are made, a nonconforming use of a building may be changed to another nonconforming use of the same, or more restricted, classification. The foregoing provisions shall also apply to nonconforming uses in districts as may be hereafter changed. Whenever a nonconforming use of a building has been changed to a more restricted use, or to a conforming use, such use shall not thereafter be changed to a less restricted use.

When a building, the use of which does not conform to the provisions of this Chapter, is damaged by fire, explosion, act of God, or the public enemy to the extent of more than sixty-five percent (65%) of its fair market value, it may only be restored upon the issuance of a permit by the Board of Adjustment as provided in Article XVII of this Chapter.

In the event that a nonconforming use of any building or premises is discontinued, or its normal operation stopped for a period of ten (10) days, the use of the same shall thereafter conform to the use permitted in the district in which it is located.

A nonconforming use occupying only a portion of a building may be extended throughout the building, if the same has been lawfully acquired and actually devoted to such use previous to the adoption of this Chapter, or to any affecting amendments thereof.

Whenever the use of a building becomes nonconforming through a change in zoning requirements or district boundaries, such use may be continued, and if no structural alterations are made, it may be changed to another nonconforming use of the same or a more restricted classification.