Is this truly Canada's Greenest Home? That's what Chris Magwood calls the single family house in Peterborough, Ontario. Chris was nervous about the claim:
We were initially quite hesitant to brand this project as “Canada’s Greenest.” The claim was not made to be boastful or to dismiss the work of other designers and builders who have made remarkably green homes… But we were very interested in pushing as many boundaries as possible with this project, to challenge ourselves as designers and builders to make the very best house possible, going beyond what has been done previously.
Whether or not it is actually the greenest, it up there for a number of reasons. Near the top is the fact that this house was built as a speculative venture; it has no subsidies, no grants or incentives. Building a house for a competitive marketplace is very different than, say, Canada's Equilibrium project or the NIST house in Maryland. Chris notes:
Placing the house on the open market will hopefully show other builders that there is an appetite for homes of this type. We believe that the market is changing and that owners are willing to invest in a home that has very low operating costs and a high degree of resilience, and which makes their health and well being a priority.
It is a test bed of the reality of market housing vs the anything-goes research project, designed to LEED platinum and Living Building Challenge standards. Things we like:
The house is built with Naturebuilt prefabricated straw bale above grade, Durisol insulated blocks below, with a little cellulose thrown in. Levels of insulation are high: Chris says "We've got R-80 in the attic, R-35 in the walls, R-28 in the basement walls and R-16 under the basement floor". It is estimated that running the air source heat pump that heats and cools the house will cost $325 per year, or as little as zero if the occupants are careful about their energy use and generate more from the photovoltaics on the roof than they use. Air tightness is 0.63 ACH/50, almost Passivhaus standards.
I have walked into a lot of new houses, and they never smelled as sweet as this. It was different, none of that plastic and drywall compound smell. That's because it is finished in wood or plaster. Every material was chosen to meet " the highest standards for being chemical free and non-toxic."
This was trouble. They wanted to source all materials from within 250km radius, (155 miles) and were able to to this with most major components, but " some categories of products are no longer manufactured in Canada, or even in North America."
Low embodied energy
You can't do much better than straw bale for that. The use of Durisol Insulated concrete forms (made from wood chips and cement) is also lower embodied energy than the typical plastic foam ICF. It's also notable that they have avoided plastic foam wherever possible, reducing reliance on petrochemicals and avoiding products containing flame retardants.
Low water use, with the potential to be self-sufficient
This is perhaps the riskiest move they have made for a house built on spec- a complete rainwater collection and filtration system and a clivus multrum composting toilet system.
By eliminating sewage output, the home dramatically lowers its environmental impacts, and by creating useful compost the toilet actually becomes a generative rather than a destructive feature.
While the foam toilet is as close as you can get to a normal toilet experience, it is not perfect (no water in the bowl when you are using it) and it does require care and maintenance. The municipality isn't crazy about people drinking rainwater or grey water disposal systems on small urban lots, so there were compromises that will affect the ability to get full Living Building Challenge certification.
A reproducible home with street appeal
-We did not want this home to be a “one-off” specialty home. Any contractor or homeowner can reproduce the results of this home with materials and products that are off-the-shelf.
-We intentionally did not choose materials or systems that would require skills, sourcing or maintenance that are outside the scope of any builder or homeowner.
-While aesthetics are a highly personal matter, we wanted to create a home that fit into an existing neighbourhood. The exterior is intended to be attractive without being “showy.”
These are important points; this isn't wildly modern or outlandish, but sits comfortably in the streetscape.
Other points they haven't mentioned.
Often we see what are called green homes sitting in exurban lots in the country or, like the NIST house, a big suburban lot; this house is very much part of Peterborough, in an established community. I was surprised that it only scored 60 on Walkscore given that it is a short bike ride to town or University, but would certainly call it urban. You could live a car-free life here quite comfortably. Given the nature of Peterborough, a canoe or kayak free life might be tougher. (It's also a short walk from this engineering marvel, a water powered lift lock)
I was also impressed that they designed the house to be universally accessible; there is a room on the ground floor that could be a bedroom and a fully accessible bathroom adjoining. At 2400 square feet it is a bit bigger than I think is optimum, and the accessibility accounts for some of that. This is a house where one could age in place, that one could stay in for a long time.
So how much does this all cost?
When Martin Holladay of Green Building Advisor first read about this house he tweeted "What does it mean when "Canada's greenest home" costs $600,000? It this a solution or part of the problem?", complaining that this kind of house is available to "only a very small segment of the population."
Actually, Martin was off, it is in fact C$ $649,000 or US$ 630,709. According to Chris Magwood, the cost premium for this house over a conventional one is about $ 80,000, mainly for the green gizmos like the solar panels, the composting toilet system and the triple glazed windows. That price includes land on an urban lot in a desirable community, it's not out in a field somewhere.
In fact, it is designed to the market here, the usual three bed, two bath detached single on an urban lot. One can question whether that is a desirable model for housing, but if you are selling spec, that's the sweet spot. If you want anything much cheaper you have to go out of town or into a condo; housing prices in Canada never crashed and are still high.
Ultimately, Canada's greenest home is going to be in a multifamily project in a truly walkable community at, yes, a more affordable price. But Chris Magwood and the team at the Endeavour Centre have stuck their necks way out, building a truly green house in a competitive market with no subsidies or support. They haven't made very many compromises in a business that usually is all about compromises and corner-cutting. It certainly is the greenest spec house in Canada, and possibly in North America.
More at Endeavour Centre