Construction for Dummies – Passive House Wall Construction

I recently was emailed photos from project manager Jake on a current Meadowlark custom home project and I was intrigued by the amount of “stuff” that was going on with the exterior walls. While working at Meadowlark for almost four years, I have seen some amazing construction techniques and have learned a ton about the latest and greatest in building technology, but this was a thermal envelope (a.k.a. exterior wall construction) that I had never seen before! I mentioned the photos to a colleague and she said that the home was being built to meet the Passive House Standard. I have heard the term mentioned lots of times, but I had never actually seen it in real life. This prompted me to look further and, like with so many of my days at Meadowlark, I learned a few things. Meadowlark Passive House 1 What is a passive house? I found this great video that takes it down to pretty simplistic principles – basically to my level! The gist is that you want to do what I have heard Meadowlark President Doug Selby say hundreds of times:  Lose less and use less, and then, if you can, produce. Make a significant envelope around your house, prevent thermal bridges, seal it from air leakage, orient it so that it can take the maximum advantage of the sun’s light, and then ventilate it properly for healthy air quality – that’s what passive homes do. Meadowlark Passive House 3 Why all of the different framing techniques in the wall? Passive House Method This is what creates the “significant envelope” around the home. In this case, you have normal stick framing  (2 X 6’s)  on the inside, then you have a special sheathing that is structural and moisture preventative and blocks air flow. The next step are the structural I-joists used vertically that will allow for lots and lots of insulation to be added to the walls. After that add fiberboard sheathing, followed by some sort of house wrap, and finally furring strips and the exterior cladding. It’s a LOT of structure, but the end result will be a home that uses about one tenth of the energy than a home built with current building standards. What are the other components of a passive house? There are many, many factors that are considered in the design and construction of a passive house. Insulation, thermal mass, solar site orientation, ventilation, and finally the number of family members living therein and their habits/preferences. All of these elements work alongside each other and should be looked at holistically in order to achieve the best end result. There is loads of information on the web, but if you are interested probably the best place to start is the Passive House Institute US.  Meadowlark also has a wealth of information in their Green Building Library on Passive Energy Strategies so take a look there also. AND…..Stay tuned for more updates on this amazing custom home project!

By Susan Christian

Leave a Reply