a new age dawning! that's amazing.
I wonder how they clean the "print" head?
After using it for concrete? Probably water, lots and lots of water. A hammer & chisel if some sets in a way that's annoying/intrusive.
BTW, this tech is at least 5 years old, though this might mark a milestone.
One nice things I was reading is that all the supply lines - water, power, data, and such would be installed in pre-created conduit. Makes upgrading easier. I wonder if it'd be possible at that scale to utilize a multiple material print system? I mean, right now 99% of 3D printers are mono-material. I'm picturing about 4 materials going into a house - concrete, insulation, permanent plastic and temporary plastic. Concrete for structure, insulation for energy savings, permanent plastic where concrete isn't appropriate(lining conduit slots, perhaps?), temporary plastic would be low-temp stuff that provides support for the rest where necessary(doors, windows?) until printing/curing finishes. After the install you go in with heat guns/knives and 'carve out' the low temp plastic for recycling. Keep it clean and that could be as simple as dumping it back in the melting-pot.