Canada’s Greenest Home is Complete!

May 24th, 2013 by Cathy Rust Leave a reply »

Canada's Greenest Home?

Chris Magwood, Executive Director of  The Endeavour Centre sent me a note letting me know that Canada’s Greenest Home is now complete and up for sale. As he mentions in his blog post on the subject, being the greenest home is not a brag per se, as those people working in the green construction industry tend to work cooperatively rather than competitively. I had a long list of questions about the home that I sent Chris’ way, and he answered each one with significant detail.

If you’re not familiar with the Endeavour Centre, is an independent school that teaches green building skills and techniques. People in the program spend half their day in the classroom and the other half building a house, getting that hands-on practical experience they need.

Using criteria from both LEED and Living Building Challenge certification systems, the team at Endeavour built what is likely to be one of the greenest homes on the market today. Not only was it built with end-use in mind, it was built with materials that have a low embodied energy. For the most part, materials come from close to home, and are made, as much as possible from renewable resources.

The house is a spacious 2300 square feet of living space on two floors. There are three bedrooms (including a Master-ensuite) on the second floor, and two bathrooms. On the main floor there is another room which can be used as a fourth bedroom, den, playroom, office, etc. in addition to the kitchen, living and dining rooms and another bathroom.

Shell: The east and west walls for both the first and second floors are made from NatureBuilt straw Structural Insulated Panels. The south side of the building is “double-framed dense packed cellulose” and the north wall is site- strawbaled. Chris estimates that the SIP walls have an R30 value, the roof has an R-80 value, the basement floor has an R-16 value, while the basement walls, built from Durisol blocks are  R-16. This is a very tight shell despite its vapour permeable walls, with an air exchange value of 0.63 ACH/hour at a standard pressure of 50 Pascal Pressure. Ross Elliot from Homesol Building Solutions  performed the energy audits throughout construction. Chris noted that the floor joists were constructed within the structure so there is no issue with having thermal bridges around the joists. Needless to say, this is a very tight building envelope!

James-St (14 of 19)

James-St (13 of 19)The windows and doors were manufactured by Inline Fiberglass. They are triple glazed (ie., three pieces of glass), argon filled with fiberglass frames. Fiberglass is one of the best materials you can use for windows and doors as the glass and fibreglass expand and contract at the same rate meaning the seal remains tight.

Because the building envelope is so tight, the house is equipped with an Air Source Heat Pump made by Mitsubishi, and an accompanying Energy Recovery Ventilator. Newer ASHPs work even in cold climates such as ours as they can find the heat in air that is -30C (provided the building envelope is tight enough). The ERV recovers heat not just from air, but also from moisture in the air so it is doubly efficient. Chris told me he wouldn’t worry about moisture in this house in any event. Because the walls are made of natural materials (straw, lime plaster, clay and wood), they are breathable and therefore can absorb moisture from the air and dry without worry of mou

Ross Eliott has estimated that with average consumption patterns the annual cost to heat the home should be about $325, taking into account average Time of Use rates in Ontario. In addition, there is a 5 kilowatt PV solar system on the roof which should generate some extra income for the homeowners as part of the microFIT program. In theory, Ross estimates that the home should run at a surplus, and that because the home is so well-insulated, it shouldn’t have any need for air conditioning (although it’s included in the ASHP). No fossil fuels are needed to run this home, and in the event that the homeowners draw more electricity than they produce, they have a contract with Bullfrog Power, a green energy retailer.

Exterior cladding is FSC pine from PurePine and are treated with Sansin stain (water-based) in the factory, and the cedar shingles were sourced in Madoc, Ontario.

Water use: There is no sewer hook-up for this home. The toilets come from a composting company in Sweden called Clivus Multrum. The system only uses 0.1L of water per flush. I’ve looked at the diagram on the Clivus website and asked Chris about it. To be honest, I was a little leery about a composting system within the home itself. The system comes with a fan, and a drainage system that separates urine from excrement and by the time the compost reaches the front of the system it is only about 10% of its original size and ready for use (it takes one to two years to reach the front of the system). My two reservations with this system are sanitation and smell. However, Clivus has been in existence since the 60s and in North America since the 70s, so maybe my reservations are unfounded. Chris noted that they have installed this system in two houses before with great success.  Despite my reservations, I can see a system such as this one being a great way for progressive cities to entice new buildings and retrofits to not use the city sewer system — provided there is a lot of training and some sort of certification system in place to make sure proper safety/sanitation measures are taken.

Because there is no need for water for the toilets, there is also no gray water system. There is a rainwater harvest system in place which can be used for any household uses including watering the garden. An overflow system lets excess rainwater  onto the front garden.

Interior finishes are a variety of materials including non-toxic acrylic paint from Mythic, AFM Safecoat Naturals paint, a homemade Clay finish, lime plaster and Kreidezeit clay. There are no toxins in this house!

Is this Canada’s Greenest house? It is durable, made of low-embodied energy, local and attractive materials, with exceptionally low running costs, that doesn’t tax the municipal sewer or electric system. Further, it blends in with its neighbours, is a reasonable size and offers typical functionality all of which are important factors in creating any “green” house. The market will decide how desirable this house is. And desirability is a key ingredient in any green house.

 

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