I absolutely love this. Reminds me of an adobe bubble house I saw in an article many years ago. Richard Olsen's Book Handmade Houses Showcases Beautiful and Unusual Homes : Architectural Digest. Probably for my future little house in Europe.
Earth Sheltered Homes and Berm Houses - a great cutaway view of how to set up a bermed home to allow light on each level, (front and back) as well as perfect indoor growing conditions for indoor gardens and green walls. It's an idea.