So, I just discovered this company called Green Magic Homes. They make modular kits for constructing earth-sheltered houses that look like Bilbo's home from The Hobbit / The Lord of the Rings. My wife and I have become particularly entranced, and are considering building one of these homes for our first house. What do you guys think? Have you heard of them before? What issues can you see this type of housing having vs. a conventional house? They cost about $41.70 per square foot (delivered), and a 3-bedroom shell can be bolted and weather-sealed by a team of 3 people in just 5-6 days. High earthquake resistance too, they can ride out a 10.0 (good for the PNW, where we're expecting "the big one" any decade now). Engineered up to International Building Code, so they are legal in the county I'm looking to build it in, too.