Cob is a mixture of clay, sand, and straw that is combined with water into a plastic mass and applied directly by hand in layers to build monolithic walls. Unlike adobe (which is formed into discrete bricks), cob is worked as a continuous plastic material — closer to pottery or sculpture than to bricklaying. This gives cob walls an organic, sculptural quality that is difficult to achieve with any other building material, and it allows curved walls, built-in furniture, and complex forms that would be expensive or impossible in conventional construction. Cob walls are extremely strong in compression and have good tensile strength due to the fiber reinforcement of the straw. They are self-supporting for wall heights up to two stories without additional reinforcement. Like adobe, cob has excellent thermal mass properties and good moisture management characteristics in appropriate climates. Cob is generally best suited to mild, temperate, and semi-arid…