Straw bale construction is one of the youngest, but probably the most well-known form of natural building, at least in North America. It has great potential not simply because it uses an abundant benign material, straw, but because of its high insulating values which equal or exceed those of super-insulated wood frame buildings. Straw is a material found where grains are grown. It is not hay, but the more inert shaft of rice, wheat, rye and other grains. When baled it has tremendous strength, able to support six times more weight than a standard 2x4 wall (Chiras, 2000).