This energy-efficient house in San Jose, California, not only produces enough solar electricity to meet its annual energy needs, it also complies with the stringent PassivhausA residential building construction standard requiring very low levels of air leakage, very high levels of insulation, and windows with a very low U-factor. Developed in the early 1990s by Bo Adamson and Wolfgang Feist, the standard is now promoted by the Passivhaus Institut in Darmstadt, Germany. To meet the standard, a home must have an infiltration rate no greater than 0.60 AC/H @ 50 pascals, a maximum annual heating energy use of 15 kWh per square meter (4,755 Btu per square foot), a maximum annual cooling energy use of 15 kWh per square meter (1.39 kWh per square foot), and maximum source energy use for all purposes of 120 kWh per square meter (11.1 kWh per square foot). The standard recommends, but does not require, a maximum design heating load of 10 W per square meter and windows with a maximum U-factor of 0.14. The Passivhaus standard was developed for buildings in central and northern Europe; efforts are underway to clarify the best techniques to achieve the standard for buildings in hot climates. standard.
The design-buildCompany that handles house design and construction. Since both services are provided by the same firm, integrated design can often be more easily achieved. team of Allen Gilliland and Bronwyn Barry of One Sky Homes were behind the spec home and succeeded in meeting the Passivhaus standard and the performance requirements of the U.S. Department of Energy’s Zero Energy Ready Home program.