S.C. Code § 23-43-130
Modular building units bearing evidence of approval must be acceptable in all localities as meeting the requirements of this chapter and must be considered and accepted equivalent to a site-built structure as meeting the requirements of safety to life, health, and property imposed by any ordinance of any local government if the units are erected or installed in accordance with all conditions of the approval. Local land use and zoning requirements, fire zones, building setback requirements, site development requirements, subdivision control, and on-site installation requirements, as well as the review and regulation of aesthetic requirements, are specifically and entirely reserved to local authorities. Those local requirements and rules which may be enacted by local authorities must be reasonable and uniformly applied and enforced without any distinction as to whether a building is a modular or constructed on site in a conventional manner. All local building officials shall enforce the provisions of this chapter and applicable regulations.
S.C. Code § 23-43-130