Feature Article

Passive House Arrives in North America: Could It Revolutionize the Way We Build?

March 31, 2010

Dan Whitmore of Blackbird Builders is using a “Larsen truss” detail in this Passive House he is building in Seattle for his family. The 14" wall cavity will be insulated with dense-pack fiberglass to achieve approximately R-55.

Photo: Dan Whitmore
I’m old enough to remember the passive-solar and superinsulation movements in the late 1970s. In 1976, I was involved with passive solar design while at college, where a group of us studied energy self-sufficiency, and in 1978 I moved to Santa Fe to work with the New Mexico Solar Energy Association, which was leading the charge in advancing passive solar energy.

Not long after passive solar began picking up steam, along came the competing idea of superinsulation. This movement, I believe, was created largely in response to early solar homes (both passive and active)—which were often complicated, ugly, expensive, and overglazed. Superinsulation proponents sought to create a simpler solution with small window areas, large quantities of insulation, and simple geometries. Proponents included researchers at the University of Illinois who built the demonstration Lo-Cal House in 1976, Canadian builders of the Saskatchewan House in 1977, and Gene Leger in Massachusetts, who built several highly publicized houses during that period. Physicist William Shurcliff helped to publicize this movement with a book and many articles on superinsulation.

While lower oil prices in North America erased much of our interest in these ideas during the 1980s, by then these concepts had migrated to Europe, where high energy taxes were keeping interest in alternatives high. Now the ideas of passive solar and superinsulation are back—in a much smarter way—with the Passive House movement.

Dr. Wolfgang Feist, who wrote his first papers on Passive House in the mid-1980s and founded the Passivhaus Institut in Darmstadt, Germany, in 1996, says that he was inspired to create ultra-low-energy buildings by physicist Amory Lovins of the Rocky Mountain Institute. As recounted by Feist in a paper available on the Passivhaus Institut website, Passive House is based on Lovins’ concept of reducing investment through energy-efficient design. “By dramatically increasing the energy efficiency of a building, the HVAC systems can be radically simplified upon reaching a certain level of efficiency,” wrote Feist.

Feist determined that when the peak heating load is kept extremely low, “the ventilation system can easily be used for space heating, and a separate heating system is no longer required.” From this, Feist derived quantitative performance standards for Passive House that made sense in Germany, based on both total annual heating energy use and total annual combined primary energy use for all applications. By getting the energy loads so small, a Passive House (known as Passivhaus in Europe) can be turned into a net-zero-energy building using a fairly small photovoltaic array.

Passive House construction has been catching on in Germany, Austria, and Scandinavian countries. More than 15,000 buildings—including single-family homes, multifamily apartment buildings, and a wide range of commercial buildings—have now been built to the standard in Europe, according to the Passivhaus Institut, and at least 17% of new homes are being built to the standard in Austria, where market penetration is the greatest.

In the United States, Passive House has been championed by Katrin Klingenberg, a German-trained architect who built the first Passive Houses in the United States with her late husband, Nic Smith, in 2002 and 2003, and later founded the Passive House Institute U.S. (PHIUS). Today, PHIUS uses a largely unchanged German Passive House standard to certify buildings in the U.S. under license from the Passivhaus Institut in Germany.