Compressed earth blocks (CE have been in use for a long time and are made from clay, sand and cement. They are biodegradable and can be made locally from any soil with a proper mix of ingredients like sand and cement. It offers fire resistance and is sound proof. Building cost can go down by 15 per cent or more. CEBs are, however, not suitable for smaller homes and buildings.http://www.ruigangmachine.com/....aac-plant/aac-block-