Waters Passive House

The Lake Simcoe watershed is home to a number of hidden environmental innovations. One of these is a lovingly-constructed Passive House in Innisfil. Passive house standards are the world’s most stringent set of building guidelines to maximize energy conservation and efficiency. The Passive House Canada and Canadian Passive House Institute websites contain more information.

At first glance, this attractive home appears just like any other. Upon entering the home, perhaps the first sign that something is different is the even temperature (another sign is the silence as the home is also very sound-proof). Heating, cooling, moisture and air circulation in a passive home is remarkably consistent, something that results in a very comfortable living environment.

Tucked away in a closet is the biggest surprise in the home—a duct heater (the size of an average hair dryer) that only uses 2 kw of energy and heats the entire home.  An efficient propane fireplace has been installed to add ambiance to the bright living area on the main floor. During construction, radiant floor heating was installed but it has never been connected since it is not needed for heating and cooling.

How is this possible? It is all in the construction. The walls of the house are 16 inches thick and are built using double wall construction. As per Passive House principals, walls are separated by 6 inches and insulation which eliminates any thermal bridging. Wall insulation is layered vertically and horizontally between the walls to minimize any heat loss. Thus the R value of the home is a wallet-friendly 65. Roof trusses are raised 24 inches to allow blown insulation to cover the entire ceiling (not just inside wall to inside wall). This brings the R value of the ceiling to an impressive 85. Other significant construction features include an innovative RAFT foundation which gives the basement of the home an R value of 50. RAFT construction uses a 12 inch Styrofoam base which holds an 8 inch poured concrete foundation supported by rebar. Exterior sheathing on the building is made of wood fibre which improves breathability and reduces any chance of mould growth.

Choice and placement of windows and doors is critical to heat retention, and passive house principles dictate the use of highly efficient windows (glass, frames and installation).  The Waters house windows have an R value of 10 (instead of the standard 3). Triple glazed, and strategically placed—the windows in this home are predominantly (30%) located on the south side of the home to capture passive solar heat in the winter and provide light in the main living area. A carefully-calculated roof overhang (using the Sustainable by Design website) provides just the right amount of shade to block unwanted solar heating in the summer.

Of note– to check for air tightness a blowerdoor test was completed once the external walls were up (prior to finishing the interior of the building). This test uncovered previously undetected air leakages in pressboard—which allowed fixes to be made during construction. The final blower door test demonstrated that the house was one of the tightest houses the tester had ever tested in Ontario.  Eliminating air leaks is a basic principal in Passive House design. Because the house is so air tight a state-of-the-art energy recovery ventilator continuously provides fresh air and balances humidity without allowing heating and cooling to escape (at 95% efficiency).

In the backyard, Low Impact Development principles were used to build a soakaway pit to collect drainage tile runoff. This feature doubles as an attractive garden element and as a functional pit that keeps surface water from flooding neighbour’s basements.

Future plans include the installation of solar panels under the MicoFIT program to compensate for electricity, and the installation of a green roof on the overhang to improve cooling and air quality. Use of an air source heat pump for water heating and house cooling will reduce energy demand even further.

The Waters Passive House uses 1/5th of the energy of an average house. If Canadians are serious about combating climate change Passive House demonstrates a clear solution for homeowners.  People will argue that it adds significant costs to construction but that is simply not true. Passive House designs take savings from the smaller or non-existant heating systems and puts it into additional insulation and better windows. Seeing is believing. The homeowner provides tours of this home during the November Passive House open house week.

Visit the Waters Passive House facebook page for more information, contact information and details around how to book a tour.

 

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