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In Snowy Whistler, a House with No Furnace

Canada's first Passivhaus points to the future of green building with wood. Second of three parts.

By Monte Paulsen, 26 Jan 2011, TheTyee.ca

AustriaHouse

Canada's first certified Passivhaus is in Whistler.

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It took three decades for the ideas embodied in the lone, landmark Saskatchewan Conservation House to return back home to Canada. And it took a group of Austrian businessmen leveraging the 2010 Winter Games to make it happen. The house itself may prove worth the wait.

Austria House, nestled just north of Whistler Village, is so well insulated that it needs no furnace. The 2,700-square-foot building requires less heat than is produced by a common household hair dryer and generates most of that meagre heating energy on-site.

The house itself now serves as a cross-country ski centre, where visitors can rent equipment or obtain directions to the Lost Lake Loop and other backcountry trails.

The way this particular Passivhaus was built also presents British Columbia policy makers with a trail map to the future of green building -- and points the way to new opportunities for the struggling B.C. wood products industry.

Shipped from Europe in containers

Canada's first certified Passivhaus was inspired -- provoked might be a better word -- by remarks Minister Colin Hansen reportedly delivered to a reception in Vienna during the build-up to the 2010 Olympics.

Europe was already home to more than 20,000 Passivhaus buildings at that time. Hansen was speaking to an audience that included some of the most experienced green builders in the world when he promised that the 2010 Winter Games would be the first "green" Olympics. When they finished chuckling, a group of Austrian builders saw an opportunity.

"They thought, 'Hey, we can show the world what green really is,'" said Matheo Dürfeld, a Whistler builder who worked on the house.

The Austrian Passive House Group was quickly formed. It included Sohm Holzbautechnik, a woodwork company that prefabricates Passivhaus buildings; Optiwin, a manufacturer of Passivhaus windows; and Drexel und Weiss, a manufacturer of heat recovery ventilators. Their plan was to prefabricate a Passivhaus in Austria, assemble it in Whistler, and rent it to the leading Austrian television network for use as a broadcast studio during the 2010 Winter Games.

"The intent of the building was not so much to show the Canadians what the Austrians can do," Dürfeld said. "Really it was more to show the Austrians what the Austrians can do."

Though prefab construction is not part of the Passivhaus standard, it has become a common method of construction in Europe. Austria House arrived in Whistler aboard six 40-foot shipping containers.

Dürfeld was hired to coordinate local construction. A log home craftsman who evolved into a builder of high-end chalets, Dürfeld and his meticulous crew chief, Manfred Haas, completed the construction.

"We didn't build the house," he said. "The Austrians sent a crew over to assemble it. We started the house for them. And after they left, we finished the house."

A soft-spoken Canadian of Austrian decent, Dürfeld is prone to self-deprecating humour. When asked why his firm was selected for the job, he quipped, "I don't know. Maybe it was only because we speak German."

In the ground: An insulated foundation

Passivhaus aficionados are obsessed with the reduction of what are called "thermal bridges." A thermal bridge is any hard material that readily conducts heat from the interior of the building to the outdoors (in winter), or vice versa (in summer). Picture the cooling fins on an air-cooled engine, or the concrete balconies that stud near every Vancouver condo tower.

"Thermal bridging is your big enemy when you are building," Dürfeld said. "The first lesson in thermal bridging is going to be in your foundation."

So while nearly every other Canadian building stands atop a concrete foundation in direct contact with the earth, Austria House stands on a concrete foundation poured atop ten inches of expanded polystyrene (EPS) foam. The foam also wraps around the sides of the foundation walls.

"This gives us in thermal mass inside the insulation," Dürfeld explained.

The air inside the house slowly heats (or cools, in summer) that thermal mass. In return, the thermal mass works to maintain a steady air temperature inside the house, rather than continually working to lower the indoor air temperature to that of the surrounding earth.

Standing atop the insulated foundation are 18-inch-thick walls that are more than twice as well insulated (R-50) as a typical British Columbia building. And atop those walls is an even more heavily insulate (R-70) roof.

But it's not just the thickness of the walls that make Canada's first Passivhaus unique. It's the way they are built. Just as veteran skiers dress in many thin layers of clothing rather than one thick parka, so the Austria House is constructed from a series of carefully designed layers.

Layer one: Solid wood mass wall

And in stark contrast to the way Canadians build, nearly every layer in this Austrian-built Passivhaus is made of wood.

As noted yesterday, the Passivhaus standard is less prescriptive than alternative green building systems like LEED or BuiltGreen.

Passivhaus doesn't tell builders how to build. Instead, it sets firm limits on the amount of energy a building is allowed to consume, then lets individual builders decide how to meet those limits.

Sohm Holzbautechnik, the general contractor that prefabricated the Austria House, not only met the standard, but did so by layering wood in ways that few British Columbians have imagined.

"The heaviest wood is on the inside," Dürfeld said during a recent tour.

Indeed, where nearly every Canadian builder installs sheets of gypsum drywall, Sohm Holzbautechnik mounted solid walls of spruce two-by-fours. The boards are stood vertically, and lined up one after another, so that only a two-inch side is visible. All of these boards are held together using patented diagonal wooden dowels, which eliminate the need for toxic glues or chemicals of any kind.

"That's not a Passivhaus standard," Dürfeld noted. "That's just the way this company prefers to build."

Like the insulated foundation, this attractive wall of solid spruce provides thermal mass that helps hold the building at a consistent temperature.

"This inside wall, the four inch mass wall, is your structure," Dürfeld said. "The rest is just a blanket."

Layer two: Plywood vapour barrier

Where Canadian builders place large sheets of plastic behind the drywall, the Austrians mount yet another layer of wood.

Austria House’s vapour barrier is built of plywood. Where one sheet of plywood joins the next, the seam is carefully taped.

"They have amazing tapes," Dürfeld said. "We have one tape we're all familiar with, the red stuff. They have different tapes for wood-to-wood, for wood-to-concrete. They have about five or six different tapes, depending on the product they are taping."

And while Canadian vapour barriers are typically punctured every few inches by staples, drywall screws and junction boxes, Passivhaus vapour barriers are sacrosanct. Wiring and plumbing is run inside the barrier (in the sold spruce wall), not through it.

"When we build dimensionally, we tend to penetrate our vapor barrier everywhere. A typical home probably has three to four hundred penetrations in its vapour barrier," Dürfeld said.

Not surprisingly, such buildings are not even close to airtight.

When subjected to a blower door test, which is designed to create a pressure difference of 50 Pascals between the interior and exterior air, a typical Canadian home might measure between four and six air changes per hour. (This is described as 6 AC/H@50Pa.) That's not ventilation; that's just leakage.

The R-2000 standard to which BuiltGreen homes aspire is 1.5 air changes per hour at the same pressure. The minimum Passivhaus standard is 0.6 air changes per hour.

Austria House rated only 0.26 air changes per hour.

"This is probably the most critical component," Dürfeld observed. "If you fail air tightness, you're simply not going to get the rest of it right."

More layers, more wood

The Austrian fetish for wood products extends to the outer layers as well.

Beyond the vapour barrier, where Canadian homebuilders install 2x6 studs (aka. thermal bridges) and fibreglass batt insulation, the Austrians install 2x12s and non-toxic insulation such as blown-in cellulose (a wood product) or mineral wool.

"The preference over there is for wood-based insulation," Dürfeld said.

The outside wall, where Canadian builders install yet another layer of plastic (such as Tyvek), the Austrians mount what they call defusion board.

"It looks like fiberboard. It's denser than a donna conna. But it can pass vapour," Dürfeld said. "Again, it's a wood-based product."

In Northern Europe, a (wood slat) rainscreen is attached to the diffusion board, and (typically wooden) siding is mounted on the outside.

The Whistler house, however, is clad with distinctive black cementations siding similar to Hardiplank. This, too, was provided by one of the building's sponsors.

Windows that shut tight

Windows are a notable exception to the Passivhaus standard's performance-based approach. This is because there is virtually no possibility of meeting the Passivhaus air tightness requirements with the relatively poor quality windows sold in North America.

"The windows are absolutely key," Dürfeld said. "That can be the biggest heat loss in your house."

In Europe, the Passivhaus standard specifies windows tested and registered by the Passivhaus Institute or affiliates. These windows are typically constructed from three panes of coated glass separated by two gas-filled chambers, each of which is more than a half-inch thick. Also, the window frames are exceptionally airtight, typically incorporating two ore more rubberized gaskets. The frames are also quite thin.

"The frame is your enemy, because the frame is less efficient. There's more thermal conductivity through the wood than through the glass and the air," Dürfeld said.

The doors are similarly constructed. And all are sealed to the vapour barrier with more specialized tapes.

"To my knowledge there are no North American made wooden doors or windows that will meet the Passivhaus standards," Dürfeld said. "This could be a business opportunity for the right company."

Buildings that breathe easy

One of the most common misconceptions about Passihaus and other airtight buildings is that they are stuffy. The truth is that because they are actively ventilated, they tend to harbour significantly higher indoor air quality than comparable buildings.

The name Passivhaus was selected to describe the intention that such buildings eschew "active" heating (such as a boiler or conventional forced-air furnace) or air conditioning systems. But nearly every Passivhaus building does include an active ventilation system called a heat recovery ventilator, or HRV.

An HRV is a device that draws cold air from the outside through one side of a series of baffles that act as a low-pressure heat exchanger. Indoor air passed through the other side of those baffles as it is expelled from the building. Thus the indoor "heat" is "recovered," as fresh air entering the building is warmed.

Heat recovery ventilators typically operate quietly and blow air much more gently than a forced-air furnace. The airflow is barely perceptible, but by running continually. In Austria House, the air is completely exchanged every 90 minutes.

"It's constant. You can never shut this thing off," Dürfeld explained.

The final 10 per cent

Superinsulation and extreme air-tightness are the core of the Passivhaus approach, and provide most of the energy savings. Dürfeld estimated that Austria House uses about 10 per cent of the energy of a comparable building.

"During construction, we were able to heat the house with one of those little 1,500-watt ceramic heaters," he said. "One day I remember, it was about seven below outside. Just really, really cold. But all your interior surfaces, floors ceilings windows walls, were all within about a degree and a half of each other."

Austria House generates much of what little heating energy it requires from a low-tech ground-source system.

Dürfeld and his crew buried three long ABS plastic hoses beneath a 20-meter-long yard in front of the building. Dürfeld described them is "giant slinkys," and said they were placed about two meters deep then covered with gravel.

The fluid that runs through these hoses is cooler than air in summer, and warmer than air in winter. It runs through a compressor, thereby creating about four kilowatts of energy. That's enough to heat the building's hot water and at times further raise the temperature of incoming air flowing through the HRV.

Lost Lake Passivhaus

Austria House worked for its builders. As seen on Austrian TV, the 2010 Winter Games looked at times like an infomercial for the Austria Passive House Group. When the games were through, they gave the house to the municipality of Whistler for use as a cross-country ski base.

The building has since been renamed Lost Lake Passivhaus.

Lost Lake Passivhaus -- nee Austria House -- is working for Whistler, too.

"We always had the vision of trying to leverage some sort of a country house in this location to help support our cross-country operation," said the city's Roger Weetman.

"It worked out fabulously," he continued. "From a sustainability perspective, it was a perfect marriage, right? It was exactly in line with what Whistler is trying to do."

And the project worked well for Dürfeld.

"This is the most interesting thing I've done in all the years I've been here," he said. "It's like taking a car from 30 miles per gallon to 100 miles per gallon."

Dürfeld's company is headed in "a whole new direction" in the wake of the Austria House project. (More about that tomorrow.)

"We're going to reinvent the envelope we live in," he said. "And then we can recreate how we build."

What remains to be seen is whether the lessons embodied in Austria House will be learned by the British Columbia wood products industry -- or, like the Saskatchewan Conservation House, politely forgotten.

Previous: Step Inside the Real Home of the Future: Passivhaus

Next: Affordable Housing that Slashes Carbon Emissions  [Tyee]

15  Comments:

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  • woodworker

    1 year ago

    Article lies it does have a furnace. A geothermal system.

    How much does this building cost above traditional Canadian stick build. My gues is close to double. Solid 2x4 wall, good for our forest industry but using over 12 times the amount of wood. Obviously only a house for the rich and foolish.

  • ShanyeKori

    1 year ago

    Windows

    There is one window manufacture that claims to meet the requirements for Passivhaus, Serious Windows make an R-11 window made with fiberglass. index.seriouswindows.com/passive-house.html

  • Rhea

    1 year ago

    Green needs to be affordable to be widely adopted

    While stories like this are really great for letting people know what the ultimate possibilities are, the cost of building a house like this is out of reach for most families, so they are likely to simply discount the entire thing as being "too expensive" or "greenwash". Same reason so many people don't buy super energy efficient windows or heating systems. Either that or building codes are so restrictive that really efficient and cost effective buildings are not allowed (like http://earthship.com).

    It is very possible to build a highly energy efficient home for the mass market. It's also possible to encourage people to build and renovate green through the use of incentives. Look at how many people took advantage of the homeowner grant or the energy efficient grant. Changing building and tax codes to make green building and renovating cheaper than traditional renovations would do a lot more to solve climate change than setting a standard too high for most people to achieve in the current market.

    What a lot of green cheerleaders miss is the fact that we have a lot of existing housing stock that's not going away right now. We're not going to tear down all the 50's neighbourhoods to build passive houses. What can be done is to change taxes, codes and practices to ensure that it's cheaper to renovate this housing stock and make it as efficient as possible than to keep building new McBurbs with crappy construction. Where new construction is put in, THAT should be held to a higher standard.

    Some things I'd like to see:

    1) Permanent and significant tax breaks on all energy efficient upgrades and new builds
    2) Energy efficient windows and heating etc. required in all new construction
    3) Public education, tax breaks and support for solar, wind and geothermal power
    4) All new construction required to incorporate solar power, water conservation, geothermal heating and cooling or heat pumps where practical
    5) Less emphasis on building cookie cutter developments that look exactly alike and perform like crap and more on building or renovating to a higher standard.

    There's tons more, but those are what I can think of right now.

  • Bytesmiths

    1 year ago

    Re: Green needs to be affordable to be widely adopted

    I agree that you have to be able to make an economic justification, but I disagree that "green needs to be affordable to be widely adopted."

    Rather, what is needed is a public education campaign to convince people that, in the long term, investing in a low-energy house is probably the best economic decision they will ever make.

    The basic problem is that we're trained to make stupid comparisons based on current prices. With coming carbon taxes, "peak oil," and the spectre of millions of electric cars driving up electricity prices, it seems a no-brainer to do whatever you can to reduce your home energy needs NOW!

    Consider that if you wait, the cost of the energy improvements in going to go up in lock-step with the cost of energy. That will leave you "behind the eight ball," since you'll not only be paying more for the energy between now and when you decide to improve, but you'll also be paying more for the energy upgrade.

    Low-energy homes are ALWAYS going to cost more. The tough job ahead is to convince people that the cost is worth it.

  • gerard

    1 year ago

    Check your assumptions

    Thanks Tyee for a good article in an interesting series. I have a few nits to pick with some of the comments though.

    'woodworker' complains of the use of solid wood, but seems to miss the point entirely—by using solid wood in a sophisticated wall assembly, they avoid the waste of energy over the entire lifespan of the building that would come with more conventional construction. 'woodworker' would apparently feel it's more virtuous to build with less wood, but burn wood to heat the house for the next 50 years.

    And I'm completely lost on woodworker's allegation that the article lies. Did you simply not read down far enough in the article to see the description of the geothermal system, or do you fundamentally disagree that it's a passive system, and consider a geothermal system the same thing as a furnace?

    Rhea, I can't quite figure out where you're coming from. You're clearly interested in things green, and reference earthship.com, which is radically green. So why all the complaint about what really is a great story that pushes the bar upward? You say people are likely to dismiss this as "too expensive" or "greenwash", but frankly this doesn't make sense. Expensive, definitely, but where is the danger that a project like this would ever come off as greenwash, which is the absolute opposite of this approach? Who would accuse the builders of this project as being less than the real deal?

    And I don't think that the passivhaus approach is in conflict with the measures you'd like to see more of. This is especially true with the 'straw man' that all kinds of good existing housing stock might be torn down to build passivhaus buildings. In fact, while I don't have any personal connection with this type of work, I've met numerous people now working on passivhaus in Vancouver & Calgary, and they're certainly interested in ways in which old housing stock can be renovated using this approach. You needn't think that publicity for this showcase project is a repudiation of more ordinary improvements to the efficiency of houses.

  • gerard

    1 year ago

    and one other thing...

    Take another look at that photo accompanying the article. Was anyone else struck by how bizarre it is to see one of those propane heaters on the deck in front of the building? And if you think about it a bit more, is there anything else that could have been in that photo that would have stood is such stark contrast to the principles described in the article? I mean, the whole point of those things is to release all of their energy into the open air.

  • EcoCollectivist

    1 year ago

    Fascinating Ideas but Oil Companies NEED Subsidization

    There are some phenomenal ideas within this article and with the concept of Passivhaus. The energy saved over the life of the house would more than pay for the expense. Since we are subsidizing the oil sands and "carbon capture technology" one might make the suggestion that we should subsidize this type of construction to make it affordable. But I suppose that wouldn't make the oil companies dividends any higher :(. O well ... I suppose subsidizing oil companies and carbon energy is the way to go. After all, these energy companies are suffering a lot economically. Not like those nasty Passivhaus builders who have money coming out of their ears.

    I will certainly be trying to implement some of the concepts and ideas of Passivhaus into the house I eventually build.

    And your right Gerard, there is an interesting juxtaposition between the carbon based energy unit and the sustainable house. I think the photographer was just trying to frame up a nice shot not thinking about the oddity.

  • Rhea

    1 year ago

    not complaining about the article...

    I'm not complaining about this article. I think it's a really great example of what CAN be done. When I say "greenwash", I'm referring to how your average Joe Lunchbucket who doesn't know much about green building and is focused on stretching his average salary to pay for the family's groceries and expensive mortgage sees this stuff. I hear it ALL. THE. TIME. from people that green projects are just for the rich, blah blah. That's because they don't understand that building or renovating a house for energy efficiency ISN'T necessarily expensive and doesn't need to involve building a whole new house. They just compare it to a stick built standard developer box and go for the lower dollar figure without understanding the payback.

    I'm fighting this battle with my husband right now...I want to replace our mid-efficiency furnace and hot water tank with a closed vertical loop geothermal system and an instant hot water heater when the time comes to replace them. We're in the Lower Mainland. Right climate, could be done, would cost about 10x what just replacing the furnace would but would pay back in energy savings and less fossil fuel dependence. Husband simply sees the cost and is set against it, dragging out arguments like "it won't work, it costs too much, blah blah". This is the kind of attitude that we need to change.

    Without understanding,"green" has become associated with ultra expensive and over budget projects like the convention centre and the Olympic Village fiasco. What is never told to people is that it's not the green factor that pushed those places over budget. It was the use of frills like high end finishings, overpriced land and poor financing/budget decisions that caused it, but people just see the news story in the Province about the cost overruns and simply think green = too expensive. I think the Tyee did an earlier article on a bunch of houses in the Gulf Islands that were cheap AND green. That's something that should be trotted out as a project example for educating people, not the platinum LEED standard with granite countertops. (snarl, grrr)

    However much I would love to see, realistically, this kind of building isn't going to be adopted en masse without a major shift in education and attitude, so I'm hoping that we might at least make smaller steps to encourage people to renovate green. Not ideal, but better than nothing.

    And I've been following peak oil for the past 10 years. It's happening now, and I don't think that the results in the next 10-50 years won't be pretty. Sadly, most people have absolutely no clue, or just don't believe/care about it. If we had continued the eco-focus of the 60's and 70's, who knows where we might be now?

    And I love the earthships. I think they are WAY cool. If I could achieve my dream, I'd leave the LM and move to North Island or up the BC coast and build an earthship and run a farm.

  • Rhea

    1 year ago

    argh, typos

    sorry for the typos in there...gah.

  • woodworker

    1 year ago

    Geo thermal

    Geothermal systems are a furnace, just as electric baseboards are. What ever heats your house. I seriously looked into these when I built my house but my geothermal engineer advised against it as my house is so energy efficient. ICF construction. cost? Maybe 5k above stickbuild which I more than saved since I didn't need to install an airconditioner for summer like all my neighbours. what happens to that system when the power goes out, no compressor, no heat. Since when was -7c really cold. That is a warm winter day in most of Canada.

  • jwstewart

    1 year ago

    No furnace in the house? I

    No furnace in the house? I guess that justifies the stainless steel one on the sidewalk used to heat the rest of the planet.

    I guess if you can afford 2700 sqft in Whistler, one shouldn't be cold outside either.

  • dave49

    1 year ago

    Good article

    For all we keep being told how green we are, they are telling us what we want to hear. We are far behind in so many ways.

    The Austrians use a lot of big wood in their traditional construction (and build to last 150 years). The Whistler Passive House prefab walls use much more wood that the traditional Canadian stick-built home. So, adapt the concept to North America and design houses that won't have neighbours complaining to city hall about your "weird-looking house". What I can't believe is how they could question the seismic stability of this house. Maybe it will jump off its slab foundation, but collapse? I think not.

    If we really valued low-energy housing, local architect Richard Kadulski would be a hero. Instead, he's known and respected in a very small and particular circle of people.

    The Whistler Passive House has a geoexchange heating system for heat and hot water, but the energy demand is so small that the field where the heat is gathered is UNDER the slab foundation. That's a really small field for geoexchange!

    Come on folks, this is a demonstration, a showpiece. Don't nitpick every little thing or it becomes too easy to say 'no' to any innovation.

  • JSoet

    1 year ago

    How does passivhaus fare in warmer climates?

    I'm just curious how passivhaus built homes fare in warmer climates, since the examples shown in these articles seem to be all be places where the houses need a lot of heating... And they get that heat from all the objects in the house that by regularly produce heat (people, hot water heater, appliances, etc.) and then keep that heat in with the great insulation...

    But in a warmer climate you're still going to have all those things producing heat inside the house so I don't see why insulation would keep it cooler, or am I missing something?

  • RickW

    1 year ago

    Green needs to be affordable to be widely adopted

    With the average price of a house in Vancouver hovering around the million dollar mark - for absolutely nothing more than 4 walls and a roof - the prices xharged for the crud that passes for a house here should easily encompass Green aspects.

  • Mountain_Villager

    1 year ago

    The Solid 2X4 walls an old and cost efficient technology

    Actually the use of solid 2x4 walls was prevalent here during the '50's and used-up the "cull" lumber that would just be chipped these days at added cost. The walls are laid up log-house-style. The insulation upgrade is easily put on the outside so that the wall, once warm, stays warm. A comfortable and quiet AND cheap construction method - not at all for the rich and foolish. Our sawmill maintenance shops, High School and several small houses were built this way for next to nothing.

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