Repairs and Maintenance. Normal maintenance repairs and incidental alteration of a building or the structure containing a nonconforming use is permitted, provided it does not extend or expand the area or volume of space occupied by the nonconforming use, or change the functional use of the building or structure.

Restoration. When a nonconforming building or structure is destroyed, or partially destroyed, by fire, explosion or other disaster, or is otherwise damaged to the extent of 50% of the appraised replacement value of such building or structure, it shall not be restored or rebuilt, except in such manner as to conform to the regulations of this chapter and amendments thereto. When a nonconforming building or structure is partially destroyed by fire, explosion or other disaster to less than 50% of its appraised replacement value, it may be restored to its original use in accordance with provisions of this chapter, but must be restored within one year of such happening.

Abandonment or Discontinued Use. A nonconforming use shall be considered abandoned or discontinued:

Sale. Any nonconforming use, structure or lot may change ownership and continue to function as the same nonconforming use, structure or lot provided that the appropriate provisions of this chapter are met.

Construction Under Permit Granted Prior to Passage. Nothing herein contained shall require any change in plans, construction, or designated use of a building for which a building permit has been heretofore issued and the construction of which shall have been diligently prosecuted within three months of the date of such permit, and the ground story framework of which, including the second tier of beams, shall have been completed within six months of the date of such permit, and which entire building shall be completed according to such filed plans within one year from the effective date of this chapter.