A. A nonconforming use of a conforming building or structure shall not be expanded or extended into any other portion of such conforming building or structure or changed except to a conforming use. In such a nonconforming use, any future use of such building, structure or portion thereof shall be in conformity with the regulations of the district in which such building or structure is located.
B. A vacant or partially vacant nonconforming building or structure may be occupied by a use for which the building or structure was designed or intended if occupied within a period of one year after the effective date of this chapter, but otherwise it shall be used in conformity with the regulations of the district in which it is located.
C. The use of a nonconforming building or structure may be changed to a use of a more restricted district classification; provided that such change in use conforms to the provisions of the district in which it is located; but where the use of nonconforming building or structure is changed to a use of more restricted district classification it thereafter shall not be changed to a use of a less restricted district classification. (1986 Code)