Section 155.8.12 Expansion or Enlargement.
   Except as provided in this Part VI, no nonconforming use shall be enlarged or expanded to occupy a greater area of land or floor area than was occupied on the date construction of such use was completed in accordance with the then existing ordinances and no additional accessory use shall be established on the site of a nonconforming use.
   (A)   For purposes of this section, a structure that is "used solely for commercial purposes" or a "commercial structure" shall mean a structure located in the zoning districts specified above that is conforming as to use and is used only for commercial purposes and no part of which is used for residential purposes. Any structure that does not meet this definition shall not be permitted to expand or enlarge as provided herein.
   (B)   A commercial structure may be expanded or enlarged to an extent that does not exceed 50% of the commercial measured area of the structure as defined in this Section 155.8.12. For purposes of calculating the permitted expansion or enlargement, all expansion or enlargement permitted under the provisions of this section within the five-year period preceding the date on which any work to enlarge or expand the structure is started shall be included.
   (C)   For purposes of calculating the commercial measured area, any deck area shall be excluded.
   (D)   Such expansion or enlargement shall not create new nonconformities.
   (E)   Such expansion or enlargement shall not encroach into an existing or required setback.
   (F)   The expansion or enlargement must maintain the following structural elements as they existed prior to the expansion or enlargement:
      (1)   The existing wall height. For the purposes of this section, existing wall height shall be measured from the top of the subfloor to the top plate of the exterior wall;
      (2)   The existing exterior walls except as needed to change/add windows and doors, to perform lateral additions or to correct code violations; and
      (3)   The original structural floor system except as needed to add new ingress and egress or to correct code violations.
   (G)   Upon completion of the expansion or enlargement, all requirements for off-street parking contained in Article 155.9, Part I must be satisfied.
   (H)   If the nonconforming structure is located ten feet or less from an adjoining structure (either on the same or on an adjoining lot) then the nonconforming structure may be not be enlarged or expanded in any manner whatsoever.
   (I)   For purposes of this section "commercial measured area" shall mean the following: all of the interior floor area of a building which is surrounded by exterior walls and/or attic with or without a laid floor with structural headroom of five feet or greater. Where a floor lies below a ceiling height of greater than 15 feet (as in a vaulted ceiling), then that area of the floor under the vertical height of greater than 15 feet shall be counted twice. One access corridor in the attic of a structure may be excluded from the commercial measured area so long as it:
      (1)   Runs parallel to the center roof ridge;
      (2)   Is no wider than three feet; and
      (3)   Does not exceed five feet in height.
(Ord. 1735, passed 11-13-14; Am. Ord. 1784, passed 4-11-19; Am. Ord. 1838, passed 3-10-22)