They’re not a gimmick, they’re dirt cheap to build relative to the quality you get (when you’re not a pack of literal community college students using a non-load-bearing material like hempcrete, working on a learning project).

The way it’s done drives the cost through the floor, even relative to a modular house, and, let’s try thinking about it for a second, if you take a liquid concrete mix and poop it out in a line and cure it properly, how is this different or worse than taking that same liquid concrete mix, dumping it into a mold you built, and then also curing it properly? Because that’s (in very simple terms) the basic difference between 3d printing houses and building them.

Basically, it’s a lot cheaper (I’ve seen multi-bedroom houses – real houses, not haha this is a big shed that you can abuse as a studio if you lie to your county planning department – printed for under $20k) and when done right, the quality is the same as any other concrete construction. The secret is just like any other construction: you have to do it right!

Right now, they’re super rare because there are no standardized building codes available for them, which means planning departments don’t have industry-standard guidance they can draw on for their own building codes, so in most places you just can’t get them approved.

Like with any technology, there will be a gold rush and tons of idiots doing it wrong or badly to turn a quick buck on the hype, but come on. New technologies are transformative, and additive construction or whatever you want to call it has tons of potential.