Last September, after receiving Passive House certification of our house, I decided to take the Certified Passive House Consultant (CPHC) course. I knew that I may never put the training to actual use. But I wanted to better understand the science behind what we built, and fortunately I had the time and resources necessary to take the class. So I thought I’d pass on my experience for anyone who might also be considering the training.
There are prerequisites that must be met for entry into the CPHC program. Generally, this means some affiliation with the building industry. But it appears that there is some flexibility, as one other student in my class appeared to have no connection to the building industry, but was taking the class because he was planning to build his own home, and, like me, was interested in the Passive House standard. In my case, the fact that I was the General Contractor on the construction of our house was evidently enough to qualify.
At $1,800, the class is not inexpensive. On top of that, if you want to be certified, it will cost an additional $300 to take the two exams; an “in-class” three-hour multiple choice exam that is accessed through your personal computer, and a “take-home” practical exam that you’re given about three weeks to complete.
The class objectives are fairly aggressive. As PHIUS puts it:
- Learn the principles of passive building design: heat transfer, air-tightness, thermal bridge free detailing, super-insulation, highly efficient ventilation, moisture control.
- Learn WUFI Passive, the next-generation passive and hygrothermal modeling tool developed in partnership with Fraunhofer IBP and Owens Corning. It’s a remarkable all-in-one performance and risk management tool for building professionals. Students receive a free 8-week license to use the full version WUFI Passive! (NOTE: Other programs require students to take energy modeling as a separate module.)
- Gain proficiency in energy modeling skills by completing an entire project including energy balancing (static and dynamic), and hygrothermal assessments of all building components and comfort assessments according to ASHRAE 55.
- Learn to implement high performance building science principles and passive house techniques in residential, commercial, and retrofit scenarios across all North American climate scenarios.
- Learn from North America’s most experienced and accomplished passive house practitioners. PHIUS instructors have designed and certified projects across the United States and Canada.
- Study built examples—including mechanical systems—for each North American climate zone.
- Learn about suitable materials and components available in local U.S. and Canadian markets, and details for passive house applications according to climate.
- Learn the best air tightness strategies, thermal bridge free detailing and how to evaluate your design in THERM.
- Learn how to assure quality and performance for your client from the design process through construction using PHIUS+ Certification & Q/A.
Although there are occasions where the entire training (with the exception of the take-home exam) is a traditional classroom event, for the most part, the training is divided into two phases. Phase 1 is a series of eight three-hour virtual classes that you “attend” via your personal computer. The sessions are live, and the attendees have the ability to ask questions via a chat function. During the class, the instructor will read each question and provide his/her answer. The sessions were titled as follows:
- Metric and Fundamentals
- The Thermal Enclosure
- Thermal Bridges and High-Performance Windows and Doors
- Ventilation Systems
- Space Conditioning
- Multi-Family and Commercial Buildings
- Quality Control (I may be mistaken on this last one, as I forgot to put it in my notes)
A variety of instructors teach the Phase 1 virtual sessions. In addition to Katrin Klingenberg, there were a number of other experienced trainers who I am confident are well-known within the high- performance building industry. Each instructor taught, at least, one three-hour block. All seemed well-versed in their subject matter and engaged in their work.
Make no mistake, the students must absorb a significant amount of information during the class, and at least during Phase 1, it is challenging (maybe even impossible) to separate the wheat from the chaff. Of course, that’s probably because there isn’t much “chaff” to begin with. Even the background information on the history of the Passive House movement has its relevance and serves as a foundation for understanding how we “got to now.” If I have a criticism, it is that there is a lot packed into each session; so much so that the instructor moves at a fairly rapid pace. So there’s not a lot of room for detail, or detailed discussions, on any particular point, which may leave the student scratching his/her head when each class is over. The students are provided with “homework” questions after each session (together with the necessary answers), and students are free to ask questions (via the electronic class forum) even weeks after a particular three-hour session has ended. But my guess is that the Phase 1 sessions will leave any serious student wishing that the classes had been in-person. Of course, the downside to that would be limited availability and greater cost (life is about compromise!).
Because of the limitations noted above, the real meat of the training occurs during the five-day in-class sessions; so much so that I almost think the serious student could miss the on-line sessions and still learn everything that is necessary to pass the exams. The beauty of the in-class sessions is (obviously) that questions can be discussed in depth and answers explained in detail. And if all of the in-class instructions are as good as the one we had (John Semmelhack) there’s really no excuse for failing to understand the required concepts. Semmelhack had a high degree of comfort with the material, an easy-going manner and the ability to simplify relatively complex concepts enough to be absorbed by (even) me.
The Phase 2 sessions ran for a fairly solid eight hours per day and basically reviewed all of the key concepts that were covered in the Phase 1 sessions (and there are quite a few). There are a lot of formulas to understand. Ever wonder about how to determine the annual heating/cooling demand for a building? Well, wonder no more. How about calculating the remaining peak load? Annual total losses? Peak losses? Converting heating degree days to heating degree hours? Transmission losses, thermal bridge losses, ventilation losses, air permeability, energetically effective air exchange rate, infiltration air change rate, the R and U value of homogeneous and non-homogeneous sections, installed U-values of windows, etc. Yes, it’s all here. Everything even the geekiest among us could ask for and more.
But not to worry. The test is open book, and a study guide is provided. So as long as the student acquires an understanding of the formulas (both how they work and when they are applied) and takes good organized notes, the tests are passable, even for those who never went beyond high-school algebra (and did that many, many, years ago).
All kidding aside, it is really an excellent class. Ours had about a dozen students. A number were architects, some were employed in various other capacities that dealt with energy efficiency, and, as previously indicated, a couple of us were just guys interested in what it takes to build a comfortable, energy efficient house. There was a lot of discussion during the class (and it was always interesting) and, assuming the general topic interests you, there’s no time for boredom.
In addition to all of the above, the class provided an introduction to WUFI Passive, and the instructor worked through some practical examples of using it, with each student following along on their own computer. Unfortunately, my computer has some personal issues that prevented me from doing the same. But it worked out just as well following along with the instructor’s computer-projected images. WUFI is an involved program that requires a fair amount of practice to attain proficiency. I’m sure it’s a powerful tool in the hands of an expert, and most likely a danger in the hands of a fool. I strongly suspect that almost without exception, each student will have to learn the program if, and when, they go through their first Passive House certification.
The three-hour multiple choice exam was given on the last day of class, and results were available immediately upon completion. Again, if you pay attention, ask questions when you don’t understand, take good notes, and organize your material, passing it is well within anyone’s reach.
The final hurdle is the take-home exam. It’s a workout. But again, if your notes are good and you don’t wait until the last minute, it’s totally achievable.
So, you might ask, what’s the point? I’ve been asking myself that question for decades, but I’ll restrict my commentary to the issue at hand. As they say in Spain, “me gusta mucho esa clase.” The class was work, but I liked it. I now have a much better understanding of the “why” that led to the “what.” When we built our house, I knew that I wanted 2×6 walls filled with cellulose and about four inches of polyiso on the outside. But I wasn’t all that sure why that was any better than any other alternative. I knew that the house had to be extremely airtight and that we had to have a ventilation system. But I didn’t know what the appropriate ventilation rate was or how it was calculated. And I had a good idea that a 9,000 btu mini-split would probably heat this place, but I had no idea how that conclusion was specifically reached (nor did the HVAC contractor, for that matter). And maybe most importantly, I had no idea of the may pitfalls that await he (or she) who assumes that they know enough to charge ahead without a solid foundation in the fundamentals (and in my view, gaining a truly “solid” foundation in the fundamentals is beyond the scope of this class).
And that last sentence leads me to what is probably the key lesson. The most important thing I learned in this class is how much I still DON’T know about building science. That isn’t meant as a failing of the class or the instructions. Rather, it’s an acceptance that like any other complex subject, it requires an ongoing commitment to learn. But as long as each student keeps the proper perspective, there will always be others willing to help along the way. After all, real knowledge isn’t so much about possessing the necessary facts as it is about knowing where to find them when they’re needed.