1.   The lawful use of a building existing at the time of the adoption of the original zoning ordinance (March 8, 1962) or at the time of a change in the district classification may be continued even though such use does not conform with the provisions thereof. 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, but whenever a nonconforming use is changed to a more restricted use or to a conforming use, it shall not thereafter be changed to a less restricted use.

2.   The nonconforming use of a building may be extended throughout those parts thereof which were manifestly arranged or designed therefor prior to adoption of this chapter.

3.   No building which has been damaged by fire, explosion, act of God, or the public enemy to the extent of more than sixty percent of its reproduction value shall be restored except in conformity with the district regulations.

4.   In the event that the nonconforming use of a building or premises in a residence district is discontinued for a period of two years or more, such building or premises shall thereafter be used only in conformity with the regulations of the district in which it is located.

5.   The casual, intermittent, temporary, or illegal use of land or buildings shall not be sufficient to establish the existence of a nonconforming use and the existence of a nonconforming use on a part of a lot or tract shall not be construed to establish a nonconforming use on the entire lot or tract.

6.   Whether a nonconforming use exists shall be a question of fact and shall be decided by the Zoning Board of Adjustment after public notice and hearing and in accordance with the rules of the Board.