For purposes of the Texas Workers' Compensation Act (the Act), §406.142, "residential structures" are buildings used as a family dwelling or multi-family dwelling, limited to a single-family residence, a duplex, a triplex, and a quadraplex. All other types of structures used for living purposes shall be considered commercial structures, and shall only be included within the scope of the Act, §406.142, if they do not exceed three stories or 20,000 square feet.
28 Tex. Admin. Code § 112.200