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Green Building in Cold Climates: Inhabitat Interview with Bernat and Kate of Maison Durable Portneuf
We’ve seen many examples of how well green buildings can work in temperate and warm climates, but what about the harsher conditions that can lash homes in rural Quebec? Inhabitat recently had the opportunity to interview Bernat Ferragut and Kate Alvo of Maison Durable Portneuf about the innovative techniques they used to create their eco-friendly, sustainable, elegant home in the woods of Portneuf, Quebec, and how they can help others do the same.
INHABITAT: How did you get involved in this building project?
It was complete chance that led us there, actually. While on a visit to the Portneuf region, we found a parcel of land that no one else wanted. It was originally listed as agricultural land but it was deemed un-useful for agricultural exploitation, since it was on a slope and was rather small for conventional farming. It had been re-slotted for residential development, so we bought it, planning to do a bit of both with it.
We purchased the land in 2010, and started on plans in January of 2011. Building began in April.
INHABITAT: Did you two have previous building experience?
Kate: I did, yes. I had done some work on my dad’s house as an opportunity to delve into a project with him, and that was my first real dip into building. Having enjoyed the process, I looked into pursuing an education in sustainable architecture or sustainable building, but I really didn’t find any programs in that field.
Finally, in 2009, I found an amazing sustainable building course taught by Chris (who now runs a school called The Endeavor Centre), and took a five-month intensive program there that combined theoretical design with hands-on experience.
INHABITAT: What challenges had to be navigated in terms of building to withstand the extreme temperatures that Quebec can experience?
Well, building in Quebec has a lot of challenges, but natural building is particularly tricky. It rains often here, so this kind of building technique requires really heavy-duty tarps everywhere to keep the straw dry during the building process. These tarps are also needed until the built walls are thoroughly plastered over as well, and since the tarps need to be of the highest, thickest grade, that’s a lot of money put towards materials that’ll just end up in landfills after several months of exposure to the elements.
Building our own home was a great learning experience, and from now on, all the walls we work with will be built indoors so they’re protected from the weather, so there’s no need to waste tarps. Pre-fabricated walls can be mounted in a day with low labour and significant ease, which eliminates a lot of headaches. We now run a business in which we act as distributors for these pre-fab walls, and since we have firsthand experience that they work amazingly well, we can reassure my customers that they’re a great, sustainable option for the Quebec climate.
INHABITAT: Are there other benefits to using these pre-fabricated straw bale walls?
The main additional benefit is that they really do look like any other walls, so contractors don’t have to learn how to work with materials that are totally alien to them. There’s nothing new to learn, no special techniques to employ: these look and work like all the other prefabricated walls they’ve worked with before. In addition, they come ready for finishing, so the additional labour costs usually associated with prefab walls are eliminated.
They’re a perfect crossover product that brings eco-conscious building options to standard contractors. You can find more information about the product at www.biomur.ca.
INHABITAT: How did you approach your heating and water system? What about insulation?
We created a shallow frost foundation by laying down gravel and then building upon that, which reduced the need for concrete. The majority of the house is raised on posts, which helps to keep the straw bale walls from any sources of infiltration and humidity on our sloped land. We did create a small basement for our workshop and heating system.
The straw bale walls provide great insulation: they’re eight feet tall, and above that is a double-wall structure filled with cellulose, which has a higher per-inch insulating value than straw bale, so the house really is super-insulated. The floor and ceiling are also insulated with cellulose. Since the house is built in a passive-solar design, facing south to maximize heat gain from the sun in winter while minimizing it in summer, our heating costs are further reduced.
The greatest thing about passive solar heating in our climate is that the coldest days of the year are usually also the sunniest days. This means that when it’s -13F outside, our heating doesn’t kick in all day, yet the house remains a cozy 77F or so.
In addition to the passive solar heating, we chose to go with a pellet boiler that pumps heated water into a three-phase water tank that can be preheated with solar thermal panels. From there, the hot water circulates into some old hot water radiators that we bought secondhand and refinished. Between the two systems, our house’s total heating bill will be around five hundred and fifty dollars for the year, including our domestic hot water, and we have yet to hook up the solar thermal panels to the system.
The windows and doors are made with fiberglass frames, which don’t expand and contract in the severe cold and heat that we get here. It’s structurally strong, doesn’t conduct heat, and doesn’t off-gas like PVC does.
INHABITAT: In addition to the straw bale walls, which techniques and materials did you use to construct your home?
We sourced the wood for the posts, beams, porch, and siding from a local mill that specializes in larch wood, which should last for a good fifty years outdoors and untreated before it may need replacing. Larch, like cedar, is extremely resistant to rotting and insect infestation, and it can last decades longer than other tree wood with little to no maintenance.
Interior structures were created from wood sourced from a man who has spent over fifty years collecting wood from houses and barns that he has taken down in the area, and the walls have all been finished with breathable paints and plasters. The final coating on the bale walls is a lime finish plaster, and the gyprock walls are painted with lime paint, both of which deter dust mites, and are anti-mold as well. These paints were sourceds from Tockay Paints in Montreal, as they specialize in natural wall finishes.
For the kitchen, we built the cabinets out of formaldehyde-free FSC finish plywood from Columbia Forest Products, and we picked up a great enamelled cast iron sink from Kohler: it’s guaranteed for life, and is made of 89% recycled materials. Our roof is made of galvanized steel, and although it has a high embodied energy, it is both extremely durable, and can be recycled. The solar panels on our porch provide us with plenty of electricity, and since we use LED lights and don’t have a clothes dryer —clothes dry just fine outside, even in the middle of winter—we really only use about 2.7kwh per day.
Our stove is fuelled by propane for now, but we hope to switch over to bio methane in the future, since it can be made onsite using a biodigestor. As for the bathroom, we have a composting toilet, which is great because it will allow us to cycle our human waste into usable fertilizer, while simultaneously saving 30% of our potable water, and reducing our impact on the municipal water treatment system. Also, composting toilets never clog!
INHABITAT: In retrospect, is there anything that you would have done differently with regard to this building project?
Definitely. Our biggest regret in this project is not having had enough knowledge about how to plan the site, and how to design and direct a responsible excavation. We have since become certified in permaculture design, and this has given us much more confidence and inspiration for helping people to plan their future building, landscaping, and water management projects.
It’s great to know that those of us who live in colder climates don’t have to sacrifice aesthetics and elegance in favour of working with sustainable, eco-conscious materials. If anyone in Quebec or Ontario would like to consult Kate and Bernat about eco-building options, or to source pre-fabricated walls for various construction needs, their contact information can be found at www.biomur.ca.
All photos by Kate Alvo
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