1.    Uses Continued or Changed. The lawful use of a building at the time of the adoption of this Zoning Code may be continued even though such use does not conform with the provisions hereof. If no structural alterations are made, a nonconforming use of a building may be changed to another nonconforming use of the same or more restricted classification. The foregoing provisions shall also apply to nonconforming uses in districts as may be hereafter changed. Whenever a nonconforming use of building has been changed to a more restricted use or to a conforming use, such use shall not thereafter be changed to a less restricted use.

2.    Use Destroyed or Damaged. No building which has been damaged by fire, explosion, act of God, or the public enemy to the extent of more than 65 percent of its assessed value, shall be restored except in conformity with the regulations of this Zoning Code.

3.    Use Stopped or Discontinued. In the event that a non-conforming use of any building or premises is discontinued or its normal operation stopped for a period of two years, the use of the same shall thereafter conform to the regulations of the district in which it is located.

4.    Use Extended. A nonconforming use occupying only a portion of a building may be extended throughout the building if the same has been lawfully acquired and actually devoted to such use, previous to the adoption of this Zoning Code or any affecting amendments thereof.