Earthbag Building, Brazil. Builder: Gabriel Raia Carneiro. Earthbag construction takes things a little further. It is based on military bunker & temporary dike building techniques. The bags are filled with clay, sand & aggregate & tamped to create cohesion. Bags are coursed like brickwork. Walls can be curved, straight, domed or topped with conventional roofs. Curved walls provide good lateral stability & straight walls longer than 5m need to be buttressed.