The project is being called Canada’s Greenest Home, which sets the bar pretty high, but the Endeavour Centre, a nonprofit building school in Peterborough, Ontario, decided the time is right.
Endeavour encourages its students to engage their minds and “get their hands dirty” on ambitious projects, including this 2,000-sq.-ft. two-story home, which is designed for an infill lot in Peterborough and will be the focus of the school’s five-month Sustainable New Construction certificate program.
“We spent a long time considering the claim we are making: Canada’s Greenest Home. We researched the many homes that have been built in this country in attempts to lower environmental impacts,” the school explained on its blog page, noting that its survey found outstanding examples of energy efficiency, land use, recycling, local sourcing, water and materials conservation, and universal accessibility for occupants. Endeavour instructors added, however, that “what we didn’t find was a home that attempted to do all of these things. A home that does of this, we figured, really would be Canada’s Greenest Home.”
Going all out
So Endeavour Centre decided to design and build its Greenest Home project to a standard that its instructors felt would address environmental, ecological, and performance issues as comprehensively and rigorously as possible: the Living Building Challenge, whose building certification program includes 20 requirements — which LBC calls “imperatives” — and a 12-month performance evaluation.
LBC identifies seven “petals,” or priorities, that each new building project must address. Four of LBC’s 20 imperatives, for example, fall under the “site” petal: limits to growth, car-free living, urban agriculture (a portion of the lot, based on the square footage of the building and its setting, must be dedicated to agriculture), and habitat exchange (which requires that for each parcel of land developed, a parcel of equal size is set aside in perpetuity).
Under LBC requirements, the Greenest Home will be expected to tightly manage its water use — it will have a rainwater collection system and gray water recycling — and to compost human waste, in this case via foam flush toilets. As GBA contributor Carl Seville pointed out in an August 2011 post about LBC, projects can also draw water from on-site wells, although LBC allows hookups to municipal water in jurisdictions that require it.
The first of many?
The house is designed to be wheelchair accessible, with a full bath and bedroom downstairs. LBC certification also requires the building to operate at net zero energy. The Greenest Home’s exterior walls will include straw-bale wall panels that will be prefabricated locally, and the building will be equipped with photovoltaic and solar hot water systems.
Chris Magwood, a founding director of Endeavour Centre, told GBA that the building’s crawlspace walls will be insulated to R-20, although the main floor will be isolated from the crawlspace with R-60 insulation in the floor joists. The exterior walls will be R-35 where the straw-bale panels are used and R-40 where the construction team will use double-stud framing. The roof will be insulated to R-70 with blown-in cellulose.
The foundation will be double-wythe earthbag, with Roxul insulation between the wythes. Fiberglass, triple-glazed Inline windows will be used throughout.
One completed, the house will be sold to help Endeavour Centre cover tuition costs. Magwood says that the construction budget for the project is about $212,500. The center’s instructors add that they hope that home’s performance and possible LBC certification will inspire Endeavour graduates and other builders to surpass the LBC standard in future projects.
Magwood noted that the Endeavor team will take a while to estimate costs for project monitoring and other verification procedures tied to LBC certification. “I honestly don’t know!” he wrote in an email to GBA. “Because we’re an educational institute, we can have faculty and students work on aspects of the certification and not have to directly pay for them. We’ll be monitoring the time involved in the certification this time around so we’ll have some sense of this figure for future projects.”