A project in the Netherlands is pioneering a new design of 3D "printed" house, using concrete "frothed" to the consistency of whipped cream. It's called Project Milestone. You can read more about it at the link; and here's a video report.
Looks interesting from the outside, but I hope the interiors would have more in the way of straight lines and squared-off corners . . . otherwise getting furniture to fit against the walls will be interesting, to put it mildly!