The Limits of Green Building With Passive House
Although Iâve touched on this before, increasing attention (and adoption) surrounding the green building technique known as Passive House (aka Passive Haus) warrants further scrutiny â and caution. To quote from the US Passive House website:
âA Passive House is a very well-insulated, virtually air-tight building that is primarily heated by passive solar gain and by internal gains from people, electrical equipment, etc. Energy losses are minimized. Any remaining heat demand is provided by an extremely small source. Avoidance of heat gain through shading and window orientation also helps to limit any cooling load, which is similarly minimized. An energy recovery ventilator provides a constant, balanced fresh air supply. The result is an impressive system that not only saves up to 90% of space heating costs, but also provides a uniquely terrific indoor air quality.â (emphasis my own).
On the surface Passive House seem great. They are after all, incredibly energy efficient houses which, from the exterior apart from window placement resemble houses in communities all across the United States and Western Europe, unlike other alternative forms of building construction.
Yet, the entire structure is predicated on very forcibly separating humans from nature. Traditionally, tightly sealed houses were avoided because tightly sealed houses lead to poor indoor air quality which leads to sick building syndrome (when inhabitants experience acute illness symptoms arising from time spent in a building or residence). Passive House overcomes those problems with a filtered air ventilator; it is this filtered air that allows Passive House to boast about its great indoor air quality.
And while it is likely that the Passive House filters do an excellent job of filtering out contaminants, they likely also filter out a number of things that human beings need. Writers Dr. Joan Maloof in her book Breathing in the Trees:
âResearchers working in the Sierra Nevada of California found 120 chemical compounds in the mountain forest air, but they could identify only 70 of them! We are literally breathing things we don't understand.â
There are virtues to living in a home where throwing open a window is a welcome thing. Imagine living in a beach front house and never smelling the ocean? Thatâs the kind of development passive house construction encourages. In other words Passive House design is incompatible with Biophilia or humanityâs innate need for international with natural systems.
Any house design that ignores that need, particularly in an era where adults spend more than 90% of their time indoors, cannot rightfully be called sustainable.