Kat Klingenberg, executive director and co-founder of the non-profit organization Phius, talks about the history and current state of passive building in the latest episode of the IMEG podcast, The Future Built Smarter. “Passive building principles are not rocket science,” she says. “We’re talking about continuous insulation, airtight construction, no thermal bridging in the envelope, good fenestration components, and minimized mechanical systems. It’s all about holistic integrated design, and once that is all implemented correctly, we get the result of super-low energy buildings that are pretty much zero-energy ready.”  

Kat also directs the technical and research programs at Phius, which certifies passive buildings and high-performance building products. The organization also has trained more than 5,000 architects, engineers, energy consultants, and builders as Phius Certified Consultants, Builders, and Raters/Verifiers. 

Predated by the construction of thousands of passive houses in North America during the 1960s through 1980s and originally modeled off the Passive House Institute of Germany, Phius codified the passive house strategies in the U.S. when the organization was founded in 2003. The principles have evolved over the past two decades and today apply not only to homes but also to new construction and retrofits of all building types, such as the Phius-certified, net-zero Prairie Trails School in Mount Prospect, IL, an IMEG project (pictured above.) Phius also now has climate-specific standards for different geographic regions. 

Passive building principles are a vital tool in the global decarbonization effort underway in the built environment—so much so that the 2024 USGBC International Greenbuild Conference will include a Phius-exclusive track, pre-conference summit, and pavilion of exhibitors.  

“There has been collaboration and friendship between the Green Building Council and Phius for quite a while, and we decided that Phius should have a track within Greenbuild this year,” says Kat. “We call it ‘Phius at Greenbuild.’ We hope that we can create a lot of interest in what we do and bring the stakeholders of Greenbuild into the fold and help them with their next challenges.” 

The urgent need to decarbonize at light speed, advances in heat pump and envelope technologies, the mastering of air tightness strategies by a growing number of builders, and the expectation that jurisdictions will begin to include Passive Building Certification as part of net-zero stretch codes (Massachusetts has already done so) are all bringing Phius into the spotlight as never before. “It’s almost like the perfect storm,” says Kat. “It’s super exciting.” 

Visit Phius on the web to learn more about the organization and its collaboration with the 2024 USGBC International Greenbuild Conference. 

Listen to the podcast: