National Association of Home Builders (NAHB) Research Center
The NAHB Research Center is conducting a study of a TerraBuilt house. The Center, a wholly-owned subsidiary of the National Association of Home Builders, is the research and development leader in the home building industry. Government agencies, manufacturers, builders, and remodelers rely on the expertise and objectivity that are at the very heart of the Research Center and its activities. Uniquely positioned to facilitate invaluable liaisons – between builders and manufacturers, design professionals and housing research, and government and industry – the Research Center is dedicated to advancing housing technology and enhancing housing affordability for the benefit of all Americans. Contact at: http://nahbrc.org/about.asp?TrackID=&CategoryID=1625&Type=
A TerraBuilt House in Rappahannock County, VA, is the subject of an ongoing NAHB-RC study
"TerraBuilt" House is being constructed as a sustainable energy-efficient dwelling. The bearing walls are dry-stack soil-cement brick using "TerraBricks," precision interlocking compressed earth bricks produced by the "GreenMachine." The house is a 2,000 square foot, one and one-half story structure designed by John Spears of the Sustainable Design Group. Several technologies listed in a Technology Inventory under the Partnership for Advancing Technology in Housing (PATH) Program, administered by the U.S. Department of Housing and Urban Development (HUD) are incorporated in the house for monitoring and evaluation of costs and performance by the NAHB Research Center, Wilson Engineering Services, and the Institute for Building Technology and Safety (IBTS).
The first floor is a concrete slab on an 18-inch thick layer of sand, a 2-inch thick layer of foam board insulation, on sand and undisturbed soil.
Heating and cooling are provided by a geothermal heat pump, water-to-water system with fan coil for cooling, and hot water for radiant floor heating system. There are three layers of cross-linked polyethylene (PEX) plastic tubing in the floor system for heating and cooling; one layer is in sand under the insulation layer, the second layer is in the center of the 18-inch sand layer, and the third layer is in the concrete slab.
Walls are constructed of 8-inch TerraBricks, with 2- to 4-inch thick exterior soy-based foam board insulation, with stucco on exterior, and plaster on interior. Windows and glass doors will have low-e double-pane glass, and doors will be insulated. Sensors have been installed to measure temperature, humidity, and energy usage, once the house is completed.
Information and photos of this ongoing study are available at:
The Sustainable Design Group Inc.
The Sustainable Design Group, Inc. (SDG) endorses the TerraBuilt construction system. The SDG has been designing green passive solar homes in harmony with man, earth and spirit since 1973. SDG specializes in innovative building systems, energy efficiency, healthy indoor environments, solar energy, water and waste systems. SDG provides sustainable design consulting services to building owners, developers, architects, and others who wish to create energy efficient and environmentally responsible projects. SDG provides comprehensive energy and environmental master planning at both the building scale as well as the larger community scale.
Contact at: http://www.sustainabledesign.com
Sandy Spring Friends School, Earth Home by Sustainable Design Group
The Earth Home is a 1200 square foot faculty house on the Sandy Spring Friends School campus in Sandy Spring Maryland. The home is constructed with 8” compressed earth bricks (TerraBricks) made by volunteers using the GreenMachine®. The walls are insulated on the outside with a soy-based foam insulation with stucco. A passive solar sunspace/greenhouse provides solar heat in winter, and provides space for a winter garden which is irrigated with grey water from the sinks. All sanitary waste is processed with a composting toilet that turns the waste to compost fertilizer for the garden. Toilets use only 1 pint of water per flush. There is also a kitchen composter for cooking scraps. The heating and cooling is a geothermal heat pump that heats water for the radiant floor and domestic hot water and chills water for summer cooling with fan coils. The roof is a green roof with plants. Electricity is provided with a 2kW grid tied photovoltaic array on the roof.