Posted on October 21, 2013 by Scott Gibson
in Q&A Spotlight
This Q&A Spotlight starts with a simple question from Anders Lewendal, a builder in Bozeman, Montana. If building to the Passivhaus standard is so cost-effective, Lewendal wants to know, why are only a handful of these houses getting built in the U.S. every year?
"Either the cost of fuel is too low or the cost of a Passive HouseA 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. is too high," Lewendal writes in a post at Green Building Advisor's Q&A forum.