Brute Force

My colleague in the Pacific Northwest, Mike Eliason, at Brute Force Collaborative, has shared his perspectives on the recent split between the Passive House Institute US (PHIUS) and the international Passive House Institute (PHI), based in Darmstadt, Germany.

As an architect with credentials from both institutions, I hope the two parties can reconcile and work together in the future. Meanwhile, the benefits for homeowners and developers of building to the Passive House standard remain unchanged. Lower utility bills, reduced noise, and better indoor air quality are just a few. And for a variety of reasons, this energy-efficiency standard works especially well in New York City.

If you follow my tweets (@DuncanArchitect), you know that I sometimes spend my Sunday mornings reading German Forschungsberichte from PHI instead of going to brunch. This particular research report detailed six years of monitoring the energy use in a school built to the Passive House standard. The report confirmed scientifically that a frost skirt can allow for less sub-slab insulation. Short term monitoring and lab experiments had previously suggested that this was true, and these findings are already incorporated in the PHPP energy modeling software. Real-world monitoring to confirm the assumptions made in energy modeling software is important, and I’m glad to see that this monitoring validates the accuracy of PHPP.

The bottom line is that the scientific basis of Passive House is strong and the rift between PHI and PHIUS won’t prevent people from being able to have a certified Passive House building with lower utility bills, reduced noise, and superior indoor air quality.

Email Greg Duncan at for more information.