Dürfeld Constructors: classic style meets super efficiency

The Rainbow Duplex in Whistler is Canada's second passive house, built by Dürfeld Constructors. It is projected to use 90% less energy for heating and cooling than a conventional building.

'We wanted to show that this could be done'

For Matheo Dürfeld, it all began with one of the earliest forms of North American houses: log cabins.

"We started in 1978 in Whistler with the advent of everyone wanting a log cabin," says the founder of Dürfeld Constructors, based in Whistler. "We did one log house after another, then we got into post and beam and heavy timber, and then glue-lam construction as things became more contemporary."

Dürfeld soon moved into general contracting, while retaining a specialty in heavy timber construction. "We started sending our guys to Built Green courses, and we learned about R-2000," he says. "So then we became more aware of the importance of building air tight homes for energy efficiency."

Olympic opportunity: Austria Passive House

Then Dürfeld Constructors was selected to build the Austria House for the 2010 Olympics, Canada's first registered Passive House. The building is now used by the Whistler municipality for offices and recreational rentals. In its most recent operating year, the 2,700 square foot building consumed a mere $233 in energy for heat.

"That building was shipped over as a pre-fabbed system from Austria," says Dürfeld, whose company worked with Austrian tradespeople on the build. From there, his company demonstrated its skills by completing Rainbow Duplex, a registered Passive House consisting of two 1,500 square foot homes designed to consume up to 90% less energy for heating and cooling than a conventional build.

"We wanted to show that this can be done," says Dürfeld. "It's one thing to say you can ship it over from Europe, and then it's another thing to say you can build it over here with Canadian products and Canadian labour, and it will perform the same as it would as if it was done over there."

The build continued a collaboration between Dürfeld Constructors and BC Passive House, a manufacturer of prefabricated panels that meet Passive House standards.

"The Power Smart New Home Program supports better building envelopes as a first line of progress to building quality, energy efficient homes," says Doug Overholt, program representative. "The Dürfeld passive house projects in Whistler illustrate the best of residential construction techniques, and Dürfeld offers tips and and suggestions that any builder could use to improve the quality of their construction.

"By sharing their expertise, Dürfeld is a valued partner helping illustrate the Power Smart New Home message, especially the energy efficiency that comes from attention to the basics — insulation, air sealing and appropriate ventilation."

Exceptional insulation and panelized construction were two of the key elements in building Durfeld Constructors "Rainbow Duplex" passive house.

Innovation based on quality

Dürfeld agrees that Canadian home buyers are only starting to understand energy efficiency, but he believes demand will grow.

"I think it will come a time where people will understand that there are choices," he says. "One of the benefits of Passive House is that you save on energy. But another big part of it is the livability and the comfort level that you're going to achieve from the house.

"You're not going to have the hot spots and cold spots that you will if your envelope is fairly compromised."

For Dürfeld, this is a question of providing quality. "We always focused on really good execution: the building looks great, the structure is solid, and so on." Now, he says, he has added superior envelope tightness and energy efficiency. (For example, Dürfeld now uses mid-construction blower door tests on every build.)

"I guess as a builder you look at doing a good foundation all the way through to looking at your baseboards and your trims, and are they as good as you can get them? And just because you can't see your air barriers and vapour barriers, as soon as you can put a number on something and give you a performance level, it's almost like getting your grade for your test. If you get a 10 versus a 2, that is something you can show your client. He or she might not care, but down the road when they can't get their heating bill under control, they will."

Dürfeld points to energy standards in various parts of Europe, where homes require third-party energy certification in order to be offered for sale, as well as planned increases in energy efficiency under the BC Building Code.

"I think soon, if you want to be recognized as a good builder, you'll need to say, 'Look, I can give you a really good envelope in addition to a really good roof and a really good foundation. Even though you can't see it, it can be measured, and I can give you good performance. I can take your car from running at 20 miles per gallon and take it up to 30 miles per gallon.'"

"Those are benefits that are tangible."