Sunday, October 28, 2007

The Healthy House: Sustainable Housing in North America

As I was reading Beatley's chapter 10: Designing Buildings and Neighborhoods with Nature in Mind, I was surprised and excited to learn about the Healthy House in Toronto. This house was built to demonstrate sustainable home building principles for Northern climates. Even though I most recently lived in Toronto, I had never even heard of the Healthy House before, but it sounded like a great example of sustainable building principles being put into practice. I felt proud that one of the few true examples of sustainble housing that Beatley could point out in North America was in my home town, but I was ashamed that I didn't know about it before this. I have often wondered how practical it would be to have a self-sufficient building in a Northern climate, but The Healthy House has shown that it can be done well.

The Healthy House was designed by architect Martin Liefhebber for a sustainable housing design competition sponsored by the CMHC (The Canada Mortgage and Housing Corporation). The house, which was built in 1996, is actually two 3-bedroom, four-story dwelling units of 1,700 square feet that require no municipal power or water inputs, nor outside sewage treatment. The annual operating costs for the house total less than $300. The Healthy House is equipped with an impressive array of on-site water filtration, solar power generation and energy-efficient design that allows the house to operate independent of the municipal grid while feeding the excess power it generates back into the municipal power supply. (healthyhousesystem.com/toronto.html)

Of course, the house was built using as many local and sustainable products as possible on a vacant lot in a Toronto neighborhood that is close to public transit. The landscape features low-input gardens with edible plants, and all the home's appliances were chosen for their energy-efficiency. The heating and cooling system for the Healthy House uses passive and active solar systems, radiant solar floors, cogeneration, photovoltaic panels, super-efficient windows, air-tight super insulation, geothermal water circulation for cooling, and trellises of deciduous plants to provide summer shade and winter sun exposure.

One of the most impressive feats of the Healthy House in Toronto is its ability to treat and recycle waste water on-site. All the water used in the house is collected from natural precipitation and stored in a limestone cistern. Thanks to a basement composter and water filtration unit, household water is recycled as much as five times before it is slowly released back into the soil in the garden. (www.cmhc-schl.gc.ca/popup/hhtoronto/htg.htm) Even toilet waste is effectively composted in the basement and grey water purified through a mix of microoganism digestion (including worms), oxygenation, ultraviolent radiation and charcoal filtration - anyone looking for more information on how this system works should check out healthyhousesystem.com/theory.html. According to the Healthy House website, the system "can reduce water consumption by up to 90% while allowing users to maintain modern consumption patterns." The house's composting and water systems attempt to mimic natural composting and water filtration systems. This is yet another example of how, by paying closer attention to natural ecological systems, we can increase the efficiency of our urban built ecosystems. Not only do the natural systems work well, they also require little to no power inputs in order to function.

How much would a house like this cost in the real world? According to the designers and builders, any home could be built to function like The Healthy House at a cost of around $120/square foot. This figure is apparently equal to the low end price for a custom-built home in Toronto.(www.eyeweekly.com/eye/issue/issue_03.06.03/city/houses.php) The Healthy House isn't that expensive to build, it can start to pay you back right away in surplus power and energy-efficiency, and it can serve the inhabitants in the same way as a regular home, but why aren't more of these types of homes being built? Some of the other blogs discuss what many European countries are doing to encourage this type of building, but Canada and the U.S. still have a lot of catching up to do.

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