Any use of a structure and/or premises existing at the time of enactment or subsequent amendment of this chapter, but not in conformity with its provisions, may be continued, provided that:
(A) The use is not changed to another nonconforming use or re-established if discontinued for a 90-day period; and
(B) No existing structure devoted to a nonconforming use shall be enlarged or extended, constructed, moved or structurally altered except in changing the use of the structure to a use consistent with the provisions of this part of the code of the city.
(2009 Code, § 905.03)