1.   Structural Alterations and Enlargements. Any building or structure in any district other than an “R” District devoted to a use made nonconforming by this chapter may be structurally altered or enlarged in conformity with the lot area, the lot frontage, yard and height requirements of the district in which situated, provided such enlargement or alteration of construction shall be limited to buildings on land owned of record by the owner of the land devoted to the nonconforming use prior to the effective date of this chapter, or shall not be greater than 50 percent of the fair market value prior to the enlargement or alteration. In the event of such structural alteration or enlargement of buildings, the premises involved may not be used for any nonconforming use other than the use existing on the effective date of this chapter.

2.   Discontinuance. In the event that nonconforming use of any building or premises is discontinued for a period of one year, the use of the same shall conform thereafter to the uses permitted in the district in which it is located. The use of land upon which no building or structure is erected or constructed which does not conform to the provisions of this chapter, and the use of land upon which no building is erected or constructed, which becomes nonconforming by reason of a subsequent change in this chapter, shall be discontinued within two years from the date of the change.

3.   Replacing Damaged Buildings. Any nonconforming building or structure damaged to an extent of 50 percent or more of its fair market value (prior to the destruction or damage by fire, flood, explosion, war, riot, or Act of God), shall not be restored or reconstructed and used as before this chapter unless brought into conformity with the provisions of this chapter.