Abstract: A modular housing system includes a plurality of hollow steel section beam members of multiple standard lengths. Each hollow steel section beam member is designed to be coupled to at least one other hollow steel section beam member wherein the hollow steel beam members and are designed to form a rectangular frame assembly. The system includes at least four hub members designed to connect rectangular frame assemblies horizontally and vertically. Hub members couple multiple rectangular frame assemblies horizontally and solid tension rod members couple multiple rectangular frame assemblies vertically. Siding and roofing members may be preinstalled within a factory environment.