On the home page of this website, I mentioned that we will be designing and building a new Passivhaus home. The obvious question, “what is that?”
For a quick summary, a passive house is a house with an air tight building envelope and lots of insulation. The outdoor temperatures stay outdoors, the indoor temperatures are stable with minimal augmentation – be it cooling in hot weather or heating in cold weather. The energy used to heat or cool a passive house is typically under 1/10th that required t heat or cool a conventionally designed and build house. Furthermore, good air quality is maintained using a highly energy efficient heat exchanger. Typically the incoming air runs through an in-ground air tube and is pre-warmed or pre-cooled before it even gets to the air exchanger, thereby increasing the overall efficiency of the system.
Actual measurements taken, be it in cold climates like Canada, Norway, or in the top of the Alps, or in warm climates like Southern Spain bear witness to this. I do however suspect the reality is better than the studies. The houses that have been tested are passive house certified houses. They are compared against the theoretical numbers of conventional housing. On the assumption that everything is build perfectly in a conventional house, that there are no gaps in insulation, no tears on the vapour barrier, every seam is sealed as it is supposed to be, then a conventional house would only use 10 times more energy as a Passive House. In reality, with minimal oversight and high speed construction mistakes are made, accidents happen, and no one corrects the problem. Based on that, I estimate the actual energy requirements of a conventional house to be 12 to 14 times more than that of a certified passive house.
Feel free to read more about Passiv Haus, or you can watch the video.