Xanadu Houses – Experimental Houses Built from Foam

Saw a good one sortof inspired by these, in the 80s.

Foam Dome Barns.

Guy would build a big earth hill, like a bread loaf. cover it with a shell of polyurethane foam, then pour a thin coat of cement over that. Leave the ends open and dig the dirt out when everything sets; add doors and finishing touches to taste. On reflection, i think there had to be support structure in the foam. Wire mesh maybe.

I never saw any bigger than car size, myself; but they bragged about the bigger ones they'd built. I think the lifetime of the foam was supposed to be 70 years but turned out to be more like 5.