For example, you could coat polyurethane with RoofKrete on both sides, because it would flex as the foam expanded and contracted in response to temperature changes, something tough to achieve with conventional concrete. If the product works as claimed -- and this really has been deployed in buildings throughout the U.K. -- then it does make it comparatively easier to construct insulated buildings without thermal bridges, and without air leaks, that use only a tiny percent of the heating and cooling energy of conventional buildings. If the claims are true, meeting or exceeding E.U. PassivHaus standards just became routine.

RoofKrete is currently only available in the U.K., but they are looking for a U.S. licensee. I hope they find one. My gut feeling is that they have a good product that does what they say, but from this distance I can't be sure. I strongly suspect it would be worth someone's while to find out.