S.C. Code Ann. § 6-29-800
(A) The board of appeals has the following powers:
(2) to hear and decide appeals for variance from the requirements of the zoning ordinance when strict application of the provisions of the ordinance would result in unnecessary hardship. A variance may be granted in an individual case of unnecessary hardship if the board makes and explains in writing the following findings:
(d) the authorization of a variance will not be of substantial detriment to adjacent property or to the public good, and the character of the district will not be harmed by the granting of the variance.
(i) The board may not grant a variance the effect of which would be to allow the establishment of a use not otherwise permitted in a zoning district, to extend physically a nonconforming use of land, or to change the zoning district boundaries shown on the official zoning map. The fact that property may be utilized more profitably, should a variance be granted, may not be considered grounds for a variance. Other requirements may be prescribed by the zoning ordinance.
A local governing body by ordinance may permit or preclude the granting of a variance for a use of land, a building, or a structure that is prohibited in a given district, and if it does permit such a variance, it may require the affirmative vote of two-thirds of the local adjustment board members present and voting. Notwithstanding any other provision of this section, the local governing body may overrule the decision of the local board of adjustment concerning a use variance.