Erica Wisner wrote:There is also some interesting work being done with earth-sheltered buildings, using smaller amounts of good-quality insulation and thermal mass, reclaimed timbers, with living roof and passive-solar elements too. Our well-drained silty soils are excellent for light-weight living roof and fast-draining earth-bermed shelters, much easier to do that sort of thing here than in the wetter, heavy-clay soils of the coastal Pacific Northwest. And the traditional winter dwelling from what I can find was a "pit-house," a timber structure half-sunk into the ground then covered with insulating reed mats and about 2 feet of earth. Sounds pretty darn fire-proof as well as winter-proof, and they were reportedly decorated and decked out with bunks and cupboards to quite an elegant standard of hospitality. I have not had the privilege of visiting a full-size one, but they had a little demo project in Oroville's Depot Museum a few summers back.