Michael Reynolds of Earthship Biotecture has lots of great ideas. Even though he uses tires (which take more time and effort) instead of earthbags, his books and videos are highly recommended. This particular video has excellent 3D modeling showing how the structure is built. Note the insulation around the perimeter of the home to create a less costly, miniature version of the PAHS system. That should be plenty of thermal mass to stabilize the indoor temperature year-round.