This U.S. industry comprises general contractor establishments primarily responsible for the entire construction of new single-family housing, such as single-family detached houses and town houses or row houses where each housing unit (1) is separated from its neighbors by a ground-to-roof wall and (2) has no housing units constructed above or below. This industry includes general contractors responsible for the on-site assembly of modular and prefabricated houses. Single-family housing design-build firms and single-family construction management firms acting as general contractors are included in this industry. Cross-References. Establishments primarily engaged in-- ? Building single-family houses on their own account for sale as speculative builders or merchant builders--are classified in U.S. Industry 236117, New Housing Operative Builders; ? Remodeling or repairing existing houses and other residential buildings--are classified in U.S. Industry 236118, Residential Remodelers; ? Performing manufactured (mobile) home setup and tie-down work--are classified in Industry 238990, All Other Specialty Trade Contractors; ? Performing specialized construction work on houses and other residential buildings, generally on a subcontract basis--are classified in Subsector 238, Specialty Trade Contractors; and ? Constructing and leasing residential buildings on their own account--are classified in Industry 531110, Lessors of Residential Buildings and Dwellings.