A nonconforming building or structure may be maintained.

Repairs and structural alterations may be made to a nonconforming building or to a building housing a nonconforming use. Any nonconforming building or portion thereof declared unsafe by the building official may be strengthened or restored to a safe condition.

A building or structure lacking sufficient automobile parking space in connection therewith as required by this title may be altered or enlarged provided additional automobile parking space is supplied to meet the requirements of this title for such alteration or enlargement.

No nonconforming building or structure shall be moved in whole or in part to any other location on the lot except by permit of the appeal authority as provided in chapter 17.76 of this title, unless every portion of such building or structure is made to conform to all restrictions of the zone in which it is located.

A nonconforming building or structure which is damaged or partially destroyed by fire, flood, wind, earthquake or other calamity or act of God may be restored, and the occupancy or use of such building, structure or part thereof which existed at the time of such partial destruction may be continued or resumed, provided that such restoration is started and completed within a period of one year.

A building or structure or portion thereof, nonconforming as to use, which is or hereafter becomes vacant and remains unoccupied for a continuous period of one year, except for dwellings and buildings to house animals and fowl, shall not thereafter be occupied except by a use which conforms to the use regulations of the zone in which it is located. Wherever a nonconforming use has been discontinued for a period of one year, such use shall not thereafter be reestablished and any future use shall be in conformance with the provisions of this title. Any building, structure or use for which a valid building permit has been issued and actual construction was lawfully begun prior to the effective date hereof may be completed and used in accordance with the plans, specifications and permit on which said building permit was granted. "Actual construction" is defined to mean the actual placing of construction materials in their permanent position, fastened in a permanent manner; actual work in excavating a basement or the demolition or removal of an existing structure begun preparatory to rebuilding; provided that in all cases actual construction work shall be diligently carried on until the completion of the building or structure involved.

The conforming use of a building or structure, existing at the time the ordinance codified in this title became effective, may be continued.

Except by permit of the appeal authority, the nonconforming use of a building or structure may not be changed except to a conforming use; but where such change is made to a conforming use, the use shall not thereafter be changed back to a nonconforming use.

The nonconforming use of land, or a portion thereof, existing at the time the ordinance codified in this title became effective, may be continued. No such nonconforming use of land shall in any way be expanded or extended either on the same or adjoining property, and provided that if such nonconforming use of land, or any portion thereof, is abandoned or changed, any future use of such land shall be in conformity with the provisions of this title.