Soil as a building material, due to its availability in quantity and its multiple uses and applications, has been used as a construction material since ancient times on all continents. It is one of the oldest building materials in the world, and to this day it is estimated that 1/3 of the world’s population lives in houses made of soil. Soil, clay and straw structures are found in Western and Central Europe, the Middle East and the Arabian Peninsula, India, China, Africa and Southwest America.