Manufactured homes have been a thing for decades now. The problem with them is that their efficiency gains don't scale. It's relatively cost effective to prod

Manufactured homes have been a thing for decades now. The problem with them is that their efficiency gains don't scale. It's relatively cost effective to produce a single-wide trailer, but not so much when producing cookie cutter two story homes with basements. For American-style suburban homes, it's most efficient to build most of the home on site, and only manufacture off-site a handful items like roof trusses. People might not realize this, but a small crew can frame several houses in a single (very, very long) day.