S.C. Code Ann. § 59-21-410: Letting of contracts.

Any construction to be financed from funds received from the State public school building fund, pursuant to the approval of the Board, shall be on public contract, such contract to be let by the trustees of the school district, and the awarding of the necessary contracts shall be in the sole province of the school district concerned. Contracts shall be let on public advertisement thereof, and on such conditions and within such limitations as the Board may approve.