Environment-Economy-Ecology (E3) House
The E3 house was built by students in the building science and appropriate technology programs at Appalachian State University. The ASU Renewable Energy Initiative allocated $30,000 towards the photovoltaic (PV) rooftop array. The 500-square-foot house is used to test innovative technologies in building practices. The E3 house gets its name from considering its design's effect on environment, economy and ecology.
Unlike most compact and transportable shelters, the structure is designed to be self-sufficient and adaptable to a variety of environmental and cultural situations. The design incorporates a blend of structural insulated panels for assembly speed and strength, combined with local construction techniques to create an energy-efficient envelope. It can accommodate up to five occupants.
The building's energy-efficient features include use of structural insulated panels (SIPs) for the building's exterior walls and roof. The panels have an insulation R-value of 30, compared to R-19 in typical home construction. The building also has solar panels, which generate energy needs for the occupants, a system to collect rainwater from the roof, and low-flow plumbing fixtures.
The PV array uses 16 panels to produce an estimated 3,745 kWh per year.