Back in 2003-2007, I worked for a home builder who vertically integrated and went for maximized modularity. In '05 we expanded our truss yard to 2 large presses and 4 automated saws, and added a wall-framing yard what worked the same way as the truss yard. Add in that they bought a concrete company to do the slabs, and a 2-story house could go from pour to sheeting in 35 days. Plumbing, electrical, and finishing jobs could take as little as an additional 30.

Since the parent company dissolved them in '08, I haven't seen any of the other subsidiaries using the same techniques or scheduling, and it's always rather surprised me. They invested literally 10s of millions of dollars into us figuring out how to make it all work, then trashed the knowledge.

The builder of the new neighborhood going up near me uses these techniques for all rooflines. They still frame on site for flooring and walls, but they crane on pre built trusses for the roofs, built nearby.

I think the lack of vertical integration could be a part of it. For example the framers don't have much incentive to make things easier for the plumbers or electricians.

There was a recent HN post on a shortage of electricians that got me to thinking why studs, which already come pre-cut to exactly 92 5/8", don't also come pre-drilled for wiring at outlet and switch height (at least I've never seen that in wood studs).

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.

Agreed, that’s why I said “experimenting”… cause as you’ve stated, it’s still not scalable. I think in time though, someone is going to disrupt this market. That’s just my opinion though.

> I believe this is why we're seeing some of the industry starting to experiment with pre-fabbed homes that are modular but can be constructed using the automation we see in car manufacturing.

Are they doing anything different than what was available in a Sears catalog 50 years ago?

Yes, the manufacturing methods used in the factories are different today. For example, you can now have all the boards nailed together by robots. Other things are still the same. Electric wiring, for instance, is still a largely manual process.

Site prep and site adaptation is a big challenge in construction. Every plot is a little different, and the pre-fab thing you want to install will need some adjustment, tweak or change that reduces the savings over just building it on-site bespoke.