Passive House Training with Passive House Academy

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Passive House Academy

I have competed the Passive House consultant/designer training and am almost ready to take the exam on Friday of this week. (eek!) Training consisted of 2 three-day sessions in Boston with instructors from Passive House Academy. There were 8 other people in my class including 5 architects, two people from European window companies and a person from an air exchanger company and I have to say that despite the difficulty and intensity of the material covered, we had fun. The instructors were Irish so, in the same way that I slip back into a Maine accent when I am talking to someone from Maine, I found myself speaking and even thinking with that lovely Irish flow. That lasted about a day and was somewhat annoying.

The course and the training is relatively new and evolving. The content of the course is all about creating super low energy use buildings using highly vetted building science. The concept is based on these 5 fundamental principles:

-Very high levels of insulation
-Avoiding thermal bridges
-Using high performance (and very nice and very expensive) windows and doors
-Airtight construction (lots of detailing and testing to insure air-tightness)
-Controlled mechanical ventilation with heat-recovery


Example of Structural Steel with no thermal bridging

This is all familiar stuff to any builder or architect who is paying attention these days but Passive house goes beyond the current codes to where codes will be in 10 to 20 years. This is passive solar design from the 70′s brought to the highest levels. It is no longer experimental but based on sound physics, a huge data base of existing projects, an understanding of moisture and air quality issues. It is also very much based on simplification. We have a huge understanding of how buildings work and how they fail so Passive House is all about using that knowledge to create buildings that succeed. For a great primer on Building science check out the Summer 2012 issue of Fine Homebuilding which you may still be able to pick up on newstands. There is an article by Kevin Ireton entitled “The Trouble With Building Science.

The economics of building to the Passive House standard are very persuasive. So persuasive that housing groups around this country including Habitat for Humanity and public housing developers are taking notice. They already took notice in Europe of course and are building many housing projects to using Passive House principles. Schools are a particularly important application of Passive House design because of air quality in particular. When you add long term operating and maintenance costs, energy costs, decreased liability issues etc. to the initial building costs, it is hard to imagine building any other way. In Europe the banks are taking notice of this as well in terms of favorable lending rates.

A big selling point is air quality and the durability of buildings. The current state of building in the U.S. is fairly dismal. Even most building and energy codes are based on a rather half-assed interpretations of building science. We have been creating buildings that are too complicated, cost too much to maintain, have air quality issues due to a number of factors often involving mold and other moisture and air quality related problems.

So the six days were spent looking at proven projects including many retrofits, studying and understanding details and products as well as overall design approach (very 70′s solar) understanding the economic issues, covering mechanical systems, understanding how buildings succeed or fail, and diving into the basic physics of it all.

An example would be: If you add x amount of insulation or upgrade the windows to a more expensive, better performing model, how much less heat will you need to pump into the building in the winter and cooling in the summer thereby saving heating and cooling costs? And not only that but can you get the heating and cooling needs low enough so that you can spend less money up front on a simpler and cheaper heating system? [note: with Passive House design, radiators -if you even need them -don't need to be under windows] And are surface temperatures in the room such that moisture will not condense on cooler surfaces in corners due to thermal bridging? – something that becomes hugely important when you super-insulate.

I really appreciate the whole concept of doing it right the first time as well as the focus on simplification. (Anyone who has looked into the mechanical room of a building built in the past thirty years should understand the need for simplification) I also appreciate that Passive House goes into a deeper level of common sense “green” than net-zero, LEED, Energy Star and all other certification type programs – some of which are rather laughable. I will repeat myself from a previous blog entry before I started this whole Passive House thing: “If the Shakers were still building, they would be building passive Houses!”

9 Comments

  1. The great flaw with Passive House is that it is a “custom design paradigm”, and one that I am afraid will never fly in the wider housing market. What we need is widespread better practices, not certifications for a narrow slice of what gets built.

  2. It’s kinda like bicycles. The high end bikes for the pros, doctors and lawyers results in a lot of trickle down effect for bikes of all price ranges. (hey! the trickle down effect works on something!) The thing I like about Passive house is that it’s not about the certification. That is a level that you can shoot for but there is no shiny metal plaque to mount next to the front door. Also that it is about budget projects like low income housing. – the Europeans have figured that out but it will take some time for Americans to look at it as anything other than custom high end stuff. It is also very compatible with what’s going on in Sweden. there is no prescriptive “method” just performance.

  3. What is going on in Sweden came about with none of this. There was no “trickle down”. It was driven by national commitment to better performance and consumer demand. The results were achieved by promoting better techniques and improving components. It did not require a “standard” or its software.

    I’m sure lots of designers will learn better practices through it, but to me it looks like a giant distraction from the problem at hand, which is creating effective and affordable methods for attaining high performance that can be adopted at an industry wide scale. This is something that will never include project by project analysis whether or not a certification is awarded. That is a “custom design” paradigm, and as any architect need not be reminded, thats not the way the industry builds.

    My fear is this is a path that takes us away from the industry and allows Housing to side step architects once again. Right now we face a problem in energy performance where architects can take a leadership role. But instead of leading it seems we will indulge ourselves with an ever more customized design process. The sad part is that we, the profession, don’t even see it.

  4. My experience with VT (which adds a big qualification to anything I say) is that legislated codes are driving up the minimum and the fact that there is a code when there was none before has made a big difference in VT. Codes are driving things in Europe as well. Some German cities will soon require Passive House Levels of construction on a city-wide scale for residential and commercial (the initial cost seem to average 8% more for residential but negligable for commercial from the numbers I’ve seen) Some of the northeastern United States are working toward PH level codes within 10 to 30 years. One thing to note about PH is the high level and percentage of post occupancy data mining which happens so seldom in the States. This provides real and valuable information such that it becomes a no-brainer for builders, banks and consumers who just want to save/make money. And, like I said, the actual certification is very downplayed and really not the point. Like it is in some other programs (LEED) Which, perhaps is bad marketing on the PH folks’ behalf. The Europeans have figured out that it costs them more not to build well. Americans haven’t figured that out yet by and large.

  5. Can you go into more information regarding the photo showing structural steel with no thermal bridging. What application was this used for and what are some others that this would be ideal for? Also, I’ve read some where condensation can occur on steel supports causing problems for the wood products used. Any information concerning this?

  6. Also, did I mention that Passive House certification is a great thing for me to market and get more of the work I love to do?

  7. The steel supports floor and roof load above but rather than pocket it into exterior walls, I put posts – you can see one in the photo) and had piers in the foundation wall to support the posts which have the added benefit of strengthening long straight foundation walls. The steel is 3/4″ shy of the exterior wall so we can slide sheetrock behind it making that intersection easier to deal with. The whole assembly – two posts and one piece of steel is then completely exposed inside the thermal envelope. Steel is a great conductor of heat energy and the enemy is condensation which would occur when inside air at 70 degrees or so hits an inside surface which is cooler. So we try to eliminate interior surfaces that are much cooler. Thus keeping the steel entirely within the thermal envelope. Where the steel posts sit on the foundation wall, they sit on a piece of plywood and a thin piece of rubber to minimize heat conduction to the colder concrete. there may be a bit of condensation there but in that location, there is no wood touching the steel. Only rigid foam and a bit of spray foam.
    phew! hope this answers the question.

  8. Yes it answered it very well. Thank you! I would love to see photos of the finished interior. Keep up the great work!! I love your designs!! Do you ever do any work for people out of state?

  9. Thanks, I will add photos as construction progresses. There will be some nice interior details as well as nice interior spaces. It may be on the Solar open house tour next fall. I work all over new England and upstate NY although a large and complicated project that is a 5 hour drive away has little appeal. I have done a bunch in Maine where I am from originally and where my family mostly is.

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