S.C. Code Ann. § 5-25-1310: Smoke detectors required for one-family and two-family dwellings, including manufactured housing.

(A) One-family and two-family dwellings, including manufactured housing, must be equipped with approved and properly functioning smoke detectors installed in accordance with National Fire Protection Association (NFPA) Standard 72E, 1990 Edition, and with NFPA Standard 74, 1989 Edition; provided, however, that the various requirements of this article apply only to dwellings and housing which are rental dwellings and housing.

(B) A newly constructed dwelling or a dwelling remodeled in excess of fifty percent of its assessed value after December 31, 1994, must be equipped with electrically powered smoke detectors. Electrical power to the smoke detectors must be a dependable, commercial electrical source. Detectors must be installed according to manufacturer's instructions.