Cob

An ancient building material created by mixing straw with clayey soil, gravel, sand, and water, shaping it either between wattle walls or into blocks and allowing it to air dry. Cob buildings if kept roofed and thus safe from water infiltration will last for hundreds of years. There is a current revival in cob construction in the UK and US, for it is environmentally sound, inexpensive, almost endlessly shapable into varied and interesting forms, and capable of being produced by home owners themselves.