Imagine that, just rolling up two trucks to a construction site: one carrying the printer, another with all the crushed rock, setting it up and letting it go. A week later, a finished home ready for a family to move into at half the cost.
Imagine that, just rolling up two trucks to a construction site: one carrying the left half of the home, and one carrying the right half. A bit of maneuvering to align them on the foundation pad, a little work connecting things up, and the family can start moving in that afternoon.
Or if you prefer a non-standard shape, how about two trucks: one carrying a collection of prefabricated floor, wall, and roof sections, and one carrying a crane and a construction crew. Takes a bit longer to assemble, but it can still be done in less than a day.
Rapid construction of houses is nothing new. I watched a neighbor's house go from foundation pad to final painting in less than a day back in the early 80s, and it was old tech even then.