Any lawful nonconforming use which existed at the time of passage of this Part 3 may be continued, and any existing building designed, arranged, intended or devoted to a nonconforming use may be reconstructed or structurally altered, subject to the following:
A.
The alterations made to such building shall in no case exceed 100% of the value of the building, nor shall the building be enlarged, unless the use therein is changed to a conforming use.
B.
No nonconforming use shall be extended at the expense of a conforming use.
C.
A nonconforming use changed to a conforming use may not thereafter change back to a nonconforming use.
D.
In the event that there is a cessation of operation of any nonconforming use for a period of 12 consecutive calendar months, the same shall be presumed to be an abandonment of such nonconforming use. Any subsequent exercise of such abandoned nonconforming use shall be deemed a violation of the terms of this Part 3.