Sec. 21-140. Historic structures.
   A.   Historic structures as accessory dwelling units in the RS-Residential District. (5-15-07)
      Historic structures are permitted as an accessory dwelling in the RS-Residential District subject to the following conditions: As an incentive to preserve historic structures and avoid their demolition, a second dwelling may be constructed on the same lot as an historic structure, and the historic structure may be used as an accessory dwelling, when all of the following conditions are met:
      1.   Prior use shall have been used as a dwelling; and
      2.   The size of the historic structure is less than twelve hundred (1200) square feet of heated space at the time of its designation as historic and is listed as an historic property as described in Section 21-94 Historic Property Designation Criteria; provided, however, that a structure reduced to less than 1200 square feet of heated space after its designation as historic may qualify for special exception approval for an additional dwelling on the same lot, but only if the Design Review Board review determines and specifies in findings, that: (5-15-07)
         a.   Special circumstances justify such reduction in square feet based on the criteria listed in Section 21-94D.(1)-(8); and (5-15-07)
         b.   The portions to be removed from the historic property were added less than 50 years ago and/or obscured an earlier feature of the historic house which contributed substantially to the most important elements of its historic character, definition and integrity. Examples of the latter instance include the removal of an enclosure of a porch when the open porch has been characteristic of a particular type of Island structure, or removal of an addition which covered a distinctive feature of the structure that is shared by neighboring structures. (5-15-07)
      3.   In the event the historic structure does not meet current FEMA elevation requirements, the Design Review Board finds that bringing it into compliance would significantly impair the historic and architectural character of the structure; and
      4.   In the event the historic structure meets current FEMA elevations requirements, the Design Review Board finds that there is no feasible design solution for an addition to the historic structure that would not significantly impair the historic and architectural character of the structure; and
      5.   No separate utility service meters shall be permitted; and
      6.   The Design Review Board must find that the height, scale, mass and placement of the second structure are appropriate to and compatible with the lot on which it is sited, the character of the historic structure and surrounding neighborhood. When necessary to achieve such appropriateness and compatibility, the Design Review Board may impose stricter limits on height, setback, size and coverage than those of the zoning standards; and
      7.   Permission to build a second structure and to use the historic structure as an accessory dwelling is approved as a special exception by the Board of Zoning Appeals; and
      8.   The following conditions as covenants running with the property shall be placed on the real estate title to the property by the owner of the lot by recording deed restrictions for the benefit of the Town of Sullivan's Island on the owner(s) title and recording the same in the RMC office for Charleston County before a building permit is issued:
         (i)   The lot shall remain in single ownership; more specifically, regardless of the type of ownership every owner, member, partner, shareholder, or unit owner, must have the same percentage of ownership in the historic structure as in any additional structure(s); and
         (ii)   Every owner, member, partner, shareholder or unit owner must have the same amount of control over the use of the historic structure as over any additional structure(s); and
      9.   If the historic structure used as an accessory dwelling is damaged or destroyed, by natural disaster, civil strife or uncontrollable accident, by more than fifty percent (50%) of its assessed value based on the most recent property assessment, the structure may be repaired in accordance with its pre-existing footprint, square footage, setbacks, and lot coverage. The Zoning Administrator shall rely on all credible information provided by the owner and/or available from the Town, to establish the damaged or destroyed structure's pre-existing condition and lot location. A Certificate of Zoning Compliance and a Building Permit shall be obtained within twelve (12) months of the date of occurrence of such damage, and once issued, construction shall be diligently pursued and completed within two (2) years from the date of the occurrence of such damage. If FEMA regulations require the structure's foundation to be elevated over fifty percent (50%) above its original elevation, the Design Review Board shall determine whether or not the reconstruction shall be required to meet the current Zoning Ordinance's Setback requirements. (2-20-24)
(Ord. 2018-07, passed 11-20-2018)
      10.   The historic structure used as an accessory dwelling may be used as a long-term rental, but only so long as the principal structure is occupied by an owner of the property as primary residence and a current business license is held on the same property. Primary residence is defined as a dwelling where the owner or owners reside on a permanent basis and are assessed at the four percent (4%) assessment rate on their ad valorem property tax.
   B.   This accessory use shall be permitted if approved as a Special Exception in the RS-Residential District under ARTICLE III. Sec. 21-20C. and upon the approval of the Board of Zoning Appeals.
(Ord. 2023-07, passed 2-20-2024)