Passive House Technology for Super Energy Efficiency


All houses have personalities but passive? It's not a word that is commonly used to describe the places we call home until now.

According to Dr. Guido Wimmers, we are poised on the edge of a revolution that will see the number of passive houses in our neighbourhoods increase dramatically.

"Passive houses were largely developed in Germany in the early 1990s comfortable, compact houses that are better insulated and better oriented to harness the power of the sun," says Wimmers, who is arguably Canada's leading passive house specialist. "Not only do they provide a healthier living environment, they operate on approximately 80 per cent less heating energy. That can translate into a 50 per cent reduction in your energy bill annually."

There are now about 40,000 to 50,000 purpose-built passive residential, commercial and institutional buildings in Europe compared to a handfulperhaps 20 to 30in BC to date. Wimmers started teaching passive-house-building science three years ago at UBC, SFU, and BCIT, and founded the Canadian Passive House Institute to offer training for professionals. He expects to see more passive houses popping up soon.

Passive house example in Whistler BC
Passive house duplex in Whistler, built by Durfeld Constructors.

"Comfort and well-being are the biggest drivers when someone decides to build a passive house," he says, "but cost efficiency is also a deciding factor. It's the most affordable way to build today. Passive houses are better built and more durable. Yes, you have to spend more up front, which means slightly higher financing costs on a monthly mortgage. But from day one, you're saving that or more on energy costs. Over the long run, energy prices are going to go up, so you're better off building a passive house. Its resale value is much higher than an ordinary house."

To meet passive house standards, a building must meet specific energy requirements. The standard is up to 10 times more stringent than levels required in regular construction in North America and generally exceeds the energy savings achieved by LEED Platinum buildings. Passive houses use an efficient building shape, thoughtful solar exposure, superinsulation, advanced windows, air tightness, ventilation with heat recovery, ventilation air preheating, and thermal bridge-free construction. The design results in improved air quality and uniform temperature levels throughout the building.
 Bernhardt passive house in Saanich BC passive house technology 
Bernhardt passive house in Saanich BC has its own Facebook page. Photo Derek Ford[/caption]

Passive house technology, Wimmers notes, is tricky to apply to older buildings undergoing renovations.

"A precondition to renovating a home to passive house standards is that the actual building needs to have a relatively high value," he cautioned. "If this is not the case, it can be difficult to achieve a financial advantage. You would need to have an emotional attachment to the home or it would need to be a heritage house."

Wimmers is one of the directors of the Canadian Passive House Institute, an educational organization that provides information about passive house design, technology and construction. The site's member directory allows viewers to find architects, engineers and contractors who specialize in passive house technology.

Wimmers himself purchased and renovated a Vancouver Special with passive house technology and components a few years ago. He spent about 25 per cent of his renovation budget on energy-efficiency upgrades for the building, which also increased noise reduction and thermal comfort.

"I was curious about how far you can go with passive house technology and an older home," he said. "Vancouver Specials are relatively compactthey're essentially boxes, and much easier to retrofit and achieve meaningful energy reductions than character homes."