Stone was expensive and something that only the rich could afford. A person that builds a house out of stone was "stone rich", while a person that builds a house out of dirt was "dirt poor". A common method to building was the wattle and daub. They start by building a sturdy frame using thick timber and fill in the gaps with sticks woven together. Then they plaster the walls with a thick fibrous mud made from wet dirt, clay, straw, and dung (because herbivores have very fibrous poop).