“I break with thee… I break with thee… I break with thee… then throw dog poop on her shoes”

So, the Passivhaus Insitute(PHI) in Germany decided to break up with Passive House Institute U.S. (PHIUS).  I really don’t know how this will ultimately impact the Passive House movement in the U.S.  I think in the short term, the impact will be pretty negative.  The fact is the U.S. no longer has a certifying body that can give out certifications on houses designed and built using the PH approach.

Dr. Feist stated that any of the other certifying bodies in the world can certify any project worldwide.  He is correct to state that the physics is the same.  However, I believe climates, building materials, custom and other factors all influence how a house is designed, built and viewed. The physics may be the same but there are bound to be lack of understanding with unfamiliar issues specific to regions of the U.S.  For example, most of the Passivhaus approach was created in climate zones that do not require much active cooling and do not experience high humidity.  The PHPP (Passive House Planning Package–Our energy modeling software) shows a clear lack of sophistication in cooling needs when comparing to the extensive heating sheets in the same program.  Here in the U.S., PH designers have been able to use PHPP’s cooling sheets but consult their own HVAC engineers for more detailed calculations partially because PHIUS is an organization run by people who are familiar the cooling needs in some parts of the country.

This is not an issue purely about climate.  There are many cultural issues at play here too.   If the PHI Passivhaus brand wants to continue to grow acceptance and in number of projects here in the U.S. they must find another certifying body in the U.S. as soon as possible or perhaps since the U.S. spans so many climate zones, instead of one, have several regional certifying bodies.

On the other hand, PHIUS seems to be “going it alone”, according to Dr. Feist.  This may not totally be a bad thing, either.  PHIUS can take this opportunity to grow without the directives and restrictions from PHI.  The original Passive House concepts came from the U.S. with the superinsulated homes built in the 70s.  Perhaps this is the time for PHIUS to start looking for its real roots and building its own name recognition.

Come to think of it, does the brand matter if the houses perform? The beauty of Passivhaus/Passive House is that as long as the energy performance criterion are met, it is a passive house. But in this world that places so much importance on name recognition, certification unfortunately matters.  I wish it didn’t but I think it is nearly impossible to get the majority of the population to understand the underlying concepts without giving it a brand.  I hate to say this but the folks behind LEED are experts salespeople and it is because of their sales and marketing skills that when people hear about green building, they immediately think of LEED.  What is the reaction you get when you mention Passive House? More than half of the time, I get “oh yeah, I know about passive solar!”

It seems such a shame when the U.S. is on the verge of entering a period of exponential growth in the most stringent performance based green building approach that this has to happen.  Well, we’ll all see what happens soon enough.

On a separate note I think the implementation of Passive House will spread wider and faster if instead of a certification process pre and during the build, you have a testing/monitoring system to see if the house after its completion is indeed operating at a “Passive House compliant” level.  Our friend Al Cobb’s ECOP system that is in beta testing does exactly that.

Anyways, here’s the open letter that Dr. Wolfgang Feist wrote yesterday and PHIUS’ Response.




3 responses to this post.

  1. […] a summary of events from inhabitat, and Roger Lin had an interesting take on next steps over on the Arlington Passivhaus blog… “On the other hand, PHIUS seems to be “going it alone”.  This may not totally be […]


  2. Posted by Tom on 2012/01/06 at 2:42 pm

    Thanks for your blog! Was checking out window installation for our upcoming PH here in the Chicago area. We’re considering the Trio, so it’s really helpful to see it here.

    But to clarify about the split–PHIUS can certify buildings as Passive Houses, though not with PHI’s stamp and backing. The way I understand the split, PHI was not letting PHIUS directly address the particulars of the US, which are many; after the split, PHIUS is focusing on serving the US market, and is now free to choose the best path, including the PHIUS+ process which is a much more robust certification process.

    Seeing Sam Rashkin and the building science community in force at the conference was very encouraging. The press about the split wasn’t good or pretty, but the results are very positive for Passive Houses in the US, I believe.


    • Hi Tom,

      Thanks for your comments. I am glad you found the blog helpful. I’ll be happy to talk to you more about Trio’s applications. I personally like the product but I think there are situations you might want to not use it. Feel free to contact me for more info.

      The original post regarding the split was made within a couple of days after the announcements and in the midst of the war of words. As you remember, was a time of great confusion for practitioners. I was frustrated with how the two groups were going at each other when the underlying physics and the general objectives remains the same.

      I am glad to see PHIUS has reemerged from the event stronger (at least I believe it is), less encumbered, while the practitioners actually never missed a beat in their work.



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