Mud, Grass, Trees and Canvas Sustainable shelter has many faces. One of the prettiest, probably the oldest, and certainly the most popular, is mud. A recently revived form, cob, comes from England and involves adding extra straw as a binder and building thick mud walls one handful at a time. Since cob was so successful for centuries in rainy England, it's not surprising that the revival on this continent started in Oregon. A new kid on the mud block is earthbag construction, a variation of the rammed earth approach in which moistened earth is placed in polyvinyl feed bags which are then stacked row upon row and tamped down.
Barbed wire laid between courses acts like a velcro mortar, holding the rows in place.
Earthbag construction is developing into a user-friendly method that combines durability with structural versatility. Strawbale is growing in popularity worldwide. The fact that it takes only months to grow grass for straw makes it an eminently renewable resource. Bamboo , the Earth's fastest growing grass, has a tensile strength equal by weight to steel. Apparently in the 40's the lumber industry saw bamboo as a threat and lobbied congress to ban its importation.