I had another comment recently from a builder who wants to build a house that breathes. I started to reply in an email and then decided to put it hereon the blog instead.
What we are doing nowadays in the world of high performance homes is based on studying hundreds of thousands of houses built in the last half century that have failed (which includes the majority of 70′s and 80′s super-insulated and passive solar homes in the northeast) and applying those lessons to building a durable house nowadays. Houses from before that time period that failed for one reason or another are mostly gone and many of those that remain are simple piggy banks for big oil. We put our money in and the oil companies take it out. Simple. (usually, I like simple but…) For the past few decades, builders in the northeast have been living in a vacuum while the northern Europeans and Canadians paid much more attention to how houses fail, learning from them and adapting. Now the conversation is opening up again and we are taking a seat at the table.
I have lived in houses that breath my whole life. It sucks. Aside from the part where you have to give your money to someone else just to not freeze to death in the winter, there is the comfort aspect of things. Houses I have lived in have never been all that comfortable whether in terms of temperature or moisture levels or even wiping mildew off the window sills. Now, with two children, I worry about the air quality and mold issues inherent in my house that breathes. I would rather be able to seal up the house in the winter and be confident that I was breathing fresh Vermont air all the time than have to step outside for a breath of fresh air or open up the doors and windows if I screw up on getting the woodstove going. Six months out of the year, I would still have the choice to open the windows and turn off the HRV.
We do seem to have more summer moisture and humidity problems than we used to but we also have access to more durable and proven materials and building methods. Some builders and architects are taking advantage of this but most are building the same way they did 20 years ago despite all the failures. A house that breathes and has little or no insulation is a barn and If you want to heat it, that means coming to terms with giving your money away. Jesse Thompson says “People breath air through their lungs, not their skin. Why should houses be any different?” If you want your house to breathe, give it a set of lungs.
There are a range of options for doing this from exhaust only bathroom fans and range hoods (simple and cheap but where does the makeup air come from in a very tight house?) to a full-on Heat Recovery Ventilation System or HRV. These are also fairly simple and effective although significantly more expensive but have the added advantages of recovering much of the heat from the outgoing air as well as providing fresh incoming air exactly where you want it. For more information just type “HRV” or “house ventilation” into the search box on Green Building Advisor and start reading.