1. General. Except as otherwise required by law, a structure or use legally established prior to the adoption date of this code may be maintained unchanged. In other than criminal proceedings, the owner, occupant, or user shall have the burden to show that the structure, lot, or use was lawfully established.
2. Discontinuance.
A. Vacancy. Any lot or structure, or portion thereof, occupied by a nonconforming use, which is or hereafter becomes vacant and remains unoccupied by a nonconforming use for a period of one year shall not be occupied, except by a use which conforms to this code.
B. Destruction. If any nonconforming structure or use is, by any cause, destroyed to the extent of 50 percent of its market value as determined by the Code Official, it shall not thereafter be reconstructed.
3. Enlargements and Modifications.
A. Maintenance and Repairs. Maintenance, repairs, and structural alterations may be made to nonconforming structures or to a building housing a nonconforming use with valid permits.
B. Change of Nonconforming Use. A change of use of a nonconforming use of a structure or parcel of land shall not be made except to that of conforming use. Where such change is made, the use shall not thereafter be changed back to a nonconforming use.
C. Additions. All additions to nonconforming structures shall conform to the requirements of this code. Additions to structures housing nonconforming uses that increase the area of a nonconforming use shall not be made.