I love that site! He's planning to produce "green" RVs. Turns out we have some of the same ideas for things to incorporate in them - I've been trying to come up with ways to make my future rig as eco-friendly as possible. Of course, most of the ideas I came up with were more for the van, and now that I'm going to get a 5th wheel... I still want awnings with solar fabric, but I haven't been able to find a place to make awnings form the fabric. I wanted multiple skylights, but the ceilings in the Americana GS (which I think I will probably get) are 5 inches thick - it's a 4 seasons rv, and I don't want to do anything to hurt that, since I want to work in Alaska at some point. I haven't asked them about the radiant heat flooring yet. I actually just love their 5th wheels as is! And they are working on a hydrogen injection system for the tow vehicles, which would be amazing!!
Of course, my loving that manufacturer has my sister believing that they must, therefore, be con-artists and the rv would fall apart the second I got it. And since it's custom built, it's not rated at rv.org. SIGH.