Clay-rich soil is mixed with water, straw, and often sand to a dough-like consistency and sculpted into walls while still wet. Under different names, the technique has been common for centuries throughout northern Europe and in parts of Asia, Africa, and the Americas. For example, there are more than 20,000 cob homes in the English county of Devon alone. Some of these homes are as much as 600 years old and still inhabited today.
The Cob Research Institute is a 501(c)3 non-profit organization founded in 2008. Our mission is to remove the legal obstacles to building with cob. Through a series of tests on soils, cob mixes, and assembly techniques, we aim to develop easy-to-follow standards for safe cob construction. Our ultimate goal is a code for cob that retains its character as a simple, ecologically sound building system.