I came across some pics of one of the earth domes a friend of mine built: this one is in Ojai, Ca. The pictures do not do it justice. They have electrical outlets and lights from solar power, a fireplace at one of the lower points, the exhaust runs underneath the dome and up some of the tiers so you get heating from below, multi levels, sun roofs,etc. He tries to use all natural or recycled but there are some things he can't (<<10%) On this particular dome I was there the day he started it(I held the stick with the string while he traced the circle of where to dig for the main dome part). He is an artist and these things are quite tough. He has done at least 3 others and is working on a couple in the high dessert of so cal. I'm considering living in one.