Siding screws directly to the tubes. Window and door openings are built into the panels and wrapped with 2x8 lumber. Roof panels sit on a ridge beam, so the entire upstairs has cathedral ceilings. The wall panels can be used below grade, too. The panels sit on a standard footing.
Treated plywood is attached to the panel and then covered with waterproofing.
A wiring chase is preformed into the wall panels and electrical boxes attach to the steel tubes. The manufacturer recommends that plumbing be located in interior partitions or in specially-built plumbing chases. Only the top chord of the metal-web floor truss bears on the outside walls. The lower chord hangs entirely inside the panel walls. According to the manuracturer, component cost is 5 percent more than typical wood-framed construction.