Here's a very cool "earth covered" (also "earth sheltered") home in Western Maryland built by homeowners who wanted to reduce their carbon footprint. By cutting out a wedge from a hillside, homeowners Phil and Lisa ensured that their home was largely protected by the elements--even with minus 10 degrees F temperatures outdoors, the home's earth-protected walls are only exposed to a steady 50 degrees F, greatly reducing heat loss and heating costs.
I'm impressed. This couple had a goal to live in a more energy-efficient home, and they did it. Now they're sharing their adventure with the world. Kudos to Lisa and Phil. Let's hope more folks out there seek to live in a similar fashion.