The most affordable way to build anything #Passivehouse #Rethink
The most affordable way to build anything
By Monte Paulsen
What does affordable really mean?
Many Canadians would suggest affordable housing means an apartment a single person can rent for 30 percent of her or his income, or a starter home for which a working couple could get a mortgage. But here in Vancouver, where real estate is a blood sport, we’ve come to regard anything under a million dollars as “affordable.” (See, Crack Shack or Mansion?)
The City of Vancouver recently invited us all to rethink what affordable housing might look like in Canada’s most expensive city. The re:THINK HOUSING challenge was initiated by Mayor Gregor Robertson’s Task Force on Housing Affordability.
Sixty-seven teams took up the re:THINK challenge. You can see them online and vote for your favourites. (Click on the stars below “Rate This Submission” to vote.)
I was honoured to collaborate on a submission with Ayme Sharma and Alexander Maurer of Marken Projects in Vancouver. We hope you’ll vote for our entry, Passivhaus Prefab: The most affordable way to build anything.
I came to know Marken Project’s work through the Rainbow Passive House is Whistler, which they designed. This simple duplex was built on a Whistler Housing Authority lot for about 10 percent more than the same construction cost as the code-minimum housing built next door. Yet these 1,500-square-foot homes consume 90 percent less heating energy than the houses next door. And they will continue to do so for the life of the building.
The average Canadian household spends $2,252 a year on heat. The average Passivhaus resident spends about $225 a year. That’s a savings of more than $2,000 a year per household. Plus tons of greenhouse gas emissions avoided every year.
That’s what affordable means to me: Save money. Save the climate.
Ayme, Alex and I started with the idea that housing affordability is comprised of three core elements: Land cost, construction cost, and operational cost. So we focused our re:THINK submission on these three factors. Here’s an excerpt:
Land Savings …few single actions within the purview of Vancouver City Council would stimulate more gentle diversity than the simple act of legalizing duplexes in all residential zones. Add an act legalizing lock-off suites within duplexes, and council will empower small-scale builders to create thousands of affordable green homes every year – at a cost of $375,000 per unit.
Construction Savings …Passivhaus Prefab is BC wood at its best. Walls, floors and ceiling panels are prefabricated from dimensional lumber and oriented strand board, then packed with recycled cellulose fibre. This wall system costs less than 2×6 walls insulated with spray foam or extruded foam boards, and produces far fewer greenhouse gas emissions. As a result, Passivhaus Prefab is the least expensive way to comply with the energy requirements of the City of Vancouver’s forthcoming building code.
Operational Savings …The average Canadian household consumes about 145 kilowatt hours of energy per square metre for space heating, according to Natural Resources Canada statistics. Passivhaus buildings consume less than 15 kWh per square metre. That’s a 90 percent savings woven into the building envelope.
Our entry also noted that the simple Passive House formula evolved from a set of Canadian ideas pioneered on early R-2000 projects such as the Saskatchewan Conservation House. You can read more about the Passive House movement’s Canadian roots in an article I wrote for the June issue of Canadian Geographic magazine.
Alex and I attended the unveiling of all 67 submissions at The Roundhouse Community Centre on July 5. I was buoyed by the variety of submissions on display and the spirited debate among those in attendance at the opening.
There were similarities between our submission and others, most notably in our overtly evolutionary approach to the land cost problem. I particularly liked the Double Double, which proposes two duplexes on a 33-foot lot. Though the energy performance of two small buildings on a narrow lot would suffer — there’s more exposed surface, and one would inevitable shade the other — the gentle density achieved in the Double Double proposal is roughly equivalent to that crafted in our proposal of a (larger) duplex with lock-off suites. (And, damn, I wish I’d thought of that title!)
I was further encouraged by the widespread recognition that prefab is the key to construction affordability.
I was disappointed, however, in the re:THINK field’s disregard for operational costs. Indeed, I was unable to find another entry that discussed operational cost as a core component of housing affordability. (I was particularly surprised to note that even the other Passive House entry failed to note the energy savings that are, in my view, the driving point of this design discipline.)
In my opinion, the lack of discussion about operational costs marked a weak spot in an otherwise interesting design competition, just as it weakens the larger discussion of which this effort is a worthwhile part.
What do you think? How do you define affordable?
Take a look at the re:THINK entries and share your thoughts in the space below. And if you agree with us that operational costs need to be talked about in the housing affordability discussion, vote for Passivhaus Prefab.
Monte Paulsen is director of Red Door Energy Advisors. He provides precise EnerGuide ratings for new and existing homes, and assists builders seeking affordable strategies to save energy. http://reddoorenergyadvisors.ca/