My wife and I just spent some time in a temperate rain-forest learning to build cob housing. The workshop was quite enjoyable, not only for skills learned, but also for camping out in an idyllic setting with such creative & motivated folk. "Cob" is a composite of clay, sand, and fiber, formed into a monolithic wall structure. The word originally meant "round," or a round blob of said composite. This material is astoundingly well suited to homes - I'm amazed that it is so "new" to North Americans. Earthquake resistance is far superior to most other building types. Thermal mass makes for excellent energy efficiency in heating and cooling. There are 2000 year old, ten story tall cob buildings in Yemen which still serve their occupants adequately. There are oodles and scads of millenium old cob houses across Europe. These things are inexpensive to build and take very little skill. I suspect we Americans have forgotten them simply because we've no way of making a profit from them. I'm curios: does anyone on this forum dwell in a cob or other earthen housing?