Compressed earth blocks ( CEB ) use a mechanical press to form blocks out of an appropriate mix of fairly dry organic, non-expansive clay and aggregate. There are many advantages of the CEB system. On-site materials can be used, which reduces cost, minimizes shipping costs for materials, and increases efficiency and sustainability. The wait-time required to obtain materials is minimal, because after the blocks are pressed, materials are available very soon after a short drying period. The uniformity of the blocks simplifies construction, and minimizes or eliminates the need for mortar, thus reducing both the labor and materials costs. The blocks are strong, stable, water-resistant and long-lasting. CEB technology has been developed for low-cost construction, as an alternative to adobe, and with some advantages : *Shipping cost: Suitable soils are often available at or near the construction site. *Non-toxic: materials are completely natural, non-toxic, and do not out-gas *Sound resistant: an important feature in high-density neighborhoods *Fire resistant: earthen walls do not burn *Insect resistant: Insects are discouraged because the walls are solid and very dense, and have no food value.