Except as otherwise provided in this chapter, uses of land, buildings or structures existing at the time of the adoption of the ordinance from which this chapter derives may be continued although the particular use of the building or structure does not conform to the regulations specified by this title for the district in which the particular building or structure is located or use is made~ provided, however, that no nonconforming structure or use of land may be extended to occupy a greater area of land, building or structure than is occupied at the time of the adoption of the ordinance codified in this title. If any nonconforming use is discontinued or abandoned, any subsequent use of such land or building shall conform to the regulations specified for the district in which such land or building is located. If no structural alterations are made therein, a nonconforming use of a nonconforming building may be changed to another use of the same or more restrictive classification upon the securing of a use permit. If the nonconforming use is replaced by a more restrictive nonconforming use, the occupancy thereafter may not revert to a less restrictive use. If any use is wholly discontinued for any reason except pursuant to a valid order of a court of law for a period of one year, it shall be conclusively presumed that such use has been abandoned within the meaning of this title, and all future uses shall comply with the regulations of the particular district in which the land or building is located. (Ord. 3-83 § 6.1, 1983)