Thermal performance of a low cost sustainable wall construction system.

Loose-fill pumice, fly ash, and sawdust have been used to construct insulated walls for retrofit or new construction of small residential buildings. Pumice in sandbags was demonstrated as exterior insulation for an existing adobe house in New Mexico. Such houses are rarely insulated because of the cost and difficulty of providing exterior insulation. Prototype stand-alone walls were also constructed using fly ash and sawdust blown into continuous polypropylene tubing, folded as it is filled to form the shape of the wall. Other materials could also be used. The construction requires no foundation or structural supports and only a small amount of Lumber. These inexpensive techniques solve the problem of insulating solid-wall houses and constructing new houses without specialized equipment and skills, thereby saving energy, reducing greenhouse gas emissions, and improving comfort for millions of people. The U.S. Department of Energy (DOE) has received U.S. Patent #5,875,607 for "Low Cost Exterior Insulation Process and Structure".