The use of any land or building, including access driveways thereto, existing at the time of passage of this chapter, even though contrary to the provisions hereof, may be continued as a nonconforming use, subject to the following restrictions and conditions:
A. No extension of use. A nonconforming use shall not be extended or enlarged, but the introduction of a conforming use into any portion of the area shall not be deemed an extension.
B. Change of use limited. Once changed to a conforming use, no land or building shall be permitted to revert to a nonconforming use.
C. Discontinued use. Whenever a nonconforming use of any land or building shall have become discontinued for a period of one year, such use shall not be thereafter resumed, and any future use shall be in conformity with the provisions of this chapter.