Im with you, the underground thing is where its at. I have a degree in architecture, and i believe that even here in our harsh Texas weather we can design places to live that are totally comfortable, with all energy derived from the earth. I have built a few wind generators, worked on adobe with the Tarahumara, and and learned some good stuff from them about thermal massing with earth and water.
Anyway my project here for me and my girl is this, we got a little farm, 4.7 acres, but it is in town, the town grew around the farm. it has a beautiful old wooden house, that im going to fix one day, but for now im setting up a "barn" to live in.
I am building it all from junk, i have a 50' Spartan Imperial Mansion, a 30' Century mahagony clipper 300' of 25' wide salvaged hog houses, free hot tub, ect.
I spent the last two weeks putting a school bus motor into a gradeall (we use it to load logs into the mills) so now i have free unlimited digging. And there is a a one acre pond on the place.
Underground rainwater catch cistern, solar/compost/fire hotwater, raditant heat/cooling tubes, 12v wind gen, and compressed air wind gen.
I got some theroies about how im gonna tie it all together, but any help from anyone who has done it would be great.