Okay, they look cool, but gawd, they are really hard to put furniture into them. Beds are square, chairs are square, tables are square, everything is square. A geodesic dome home is NOT square...
Okay, enough of that. To each his own.
A HOMEMADE infloor heating and cooling system.... And WHERE is Mr. Contractor going to be in 8 years when this homemade system starts spraying water through the control joints???
I am a bit suspect, sorry to say. The system may in fact be bulletproof, I can't see it from here. DO get some OTHER estimates. Search the internet for alternative brands. (You can download my favorite search tool at www.copernic.com)
Sorry, I'm sure your new home will be very nice. I just haven't run into a new one since 1979.