This is awesome.
A couple of questions though:
What's the R-value like compared to a conventional house c/w 6" insulated walls? (by the looks of it, quite a bit higher given how they're so much thicker.)
It said that it was 38 square metres and only $10,413 to build, or $274/metre squared, but an 'average' house is cheaper - @ about $223? Say what?
couldn't find exact figures, but given the concrete + foam, I do believe it's pretty high. As for the price, depends where you are in the world, but in the U.S. that would be crazy cheap for a concrete structure, though it's also likely to be quite a bit more expensive here too as you still need the plumbing, electric, etc.
Here's a thread about it on slashdot: 3D-Printed House Constructed On-Site In One Day.