Abstract: The present invention provides a light gauge sheet metal building construction system which has a complete exterior shell that includes all exterior walls, floors and the roof. The invention permits the pre-assembly of a sheet metal cell unit building component comprised of bent sheet metal panels connected together to form a cell unit. This component can be used for a floor system, a varying wall system, or a rigid frame roofing system for residential, commercial, or industrial building applications. It is an alternate framing system for conventional wood framed and conventional metal stud framing systems.