S.C. Code § 31-3-930
The legislative delegation of each of two or more contiguous counties shall by resolution declare that there is a need for one regional housing authority to be created for all of such counties to exercise powers and other functions herein prescribed in such counties only if each such legislative delegation finds (a) that in the area of its county there are unsanitary or unsafe inhabited dwelling accommodations or there is a shortage of safe and sanitary dwelling accommodations available to persons of low income at rentals they can afford and (b) that a regional housing authority would be a more efficient or economical administrative unit than a housing authority of such county to carry out the purposes of the Housing Authorities Law in such county. In determining whether dwelling accommodations are unsafe or unsanitary such legislative delegation may take into consideration the safety and sanitation of dwellings, the degree of overcrowding, the percentage of land coverage, the light, air space and access available to the inhabitants of such dwelling accommodations, the size and arrangement of the rooms, the sanitary facilities and the extent to which conditions exist in such buildings which endanger life or property by fire or other cause. Each such resolution shall be sufficient if it declares that there is a need for the regional housing authority and finds in substantially the foregoing terms (no further detail being necessary) that the conditions enumerated in (a) and (b) exist.
S.C. Code § 31-3-930