Former builder here. The idea is great, but it seems fixated on the building shell, which is by far the cheapest part of the house. The electrical, plumbing, foundation, flooring, plaster, sidewalk, fencing, driveway and roofing work, the baths and kitchens, windows, doors, siding and trim are where all the money goes.
I do like the idea of being able to print out the complex stuff, say the framing for an archway or stairway. Otherwise, no way 3D printing can compete with pre-cut 2x4s.
Yawn. Let me know when it's out of the lab.