Winters can be deceptively cold on the West Coast of British Columbia (BC). People from Fort McMurray, Alberta – where temperatures often drop to minus 40 – tell me they did not feel the chill back home. It’s the damp cold that soaks into your bones. Hearing this, some of you may be surprised to find that the house pictured above was heated by two little 500 watt heaters through the coldest part of winter. Rob Bernhardt says, “It is the first Vancouver Island home targeting certification under the international Passive House standard.” (That’s quite a mouthful!) I would phrase that a little differently, this could be Vancouver Island’s first passive house.
He told me they are common throughout much of Europe. There are tens of thousands, and many passive houses are in Austria and Belgium. The European Union has decided that all new buildings throughout Europe must meet an equivalent level of energy efficiency by 2020. Passive homes are no longer considered innovative in the EU, as building standards, including the Passive House standard, move toward energy self-sufficiency and generation.
There are some passive homes in BC. Rob is aware of passive houses in Greater Vancouver, Nelson, Fort St John, and four in the ski lover’s haven of Whistler.
When Rob’s son, Mark Bernhardt, a building contractor in Victoria, investigated building standards, he came across comments that high performance buildings were too expensive, they were not practical in North American, etc. “But as we investigated Passive House, we could not see anything particularly expensive and it is well proven.” Rob said. “It made sense to construct high performance buildings.”
They decided to build a two family residence in Sannich, close to Cedar Hill Golf Course. Mark and his family now live in the top floor, and Rob & his wife on the lower level.
A Passive House, for those of you unfamiliar with the concept, uses as little as 10% of the energy required by conventional houses. They achieve this by designing a more efficient building envelope.
There are no floor joists that extend outside to hold a balcony. “That’s a thermal bridge, transferring heat to the exterior.” Rob explained.
Contrary to what many of us think, concrete is not inherently cold, but it soaks up the temperature of whatever touches it. Insulate concrete, so that it no longer picks up cold from the ground, and it will become room temperature.
Look at those big windows in the Bernhardt residence. “The primary source of heat in a passive house is sun coming through the window.” Secondary sources are internal heat gains from appliances, cooking, and even body heat. Because heat is not constantly escaping, even baking bread can generate warmth in the winter. In the summer, ventilation (natural or mechanical) removes excess heat coming from internal heat gains.
The Bernhardt’s experience is an excellent illustration of how efficient this can be. They discovered a problem with the hydronic coil in late November/early December that was not repaired until January. In the interval, they heated a 3,300 square foot house by intermittently using two heaters whose combined output is equivalent to that of a hair dryer.
“We were very comfortable,” he said.
Rob added that people who want to have a zero net energy home can add solar panels, and they will not need as many as a conventional house.
“The most economic solution is first of all energy conservation,” he added. “Then meet the small demand with renewables.”
The prospect of adding a battery system, so that he could live independent of the grid, was not financially attractive.
I had a similar response recently, when interviewing the deputy director of Yolo County General Services. Yolo has installed a sufficient amount of solar to pay off the county administration’s energy bill, plus receive $500,000 a year for the surplus energy they feed into the grid. There is no incentive for them to have a solar-plus-battery system, but there is an incentive to add more energy. The deputy director wants to add enough to generate an additional $5 million in revenue per year.
Given the little amount of energy they require, Passive Houses could easily be transformed into smaller scale power generators.
“A Passive House requires only a fraction of the heating that conventional buildings do,” Rob said. “There are no cold spots, no condensation on windows. Close the windows and all traffic noise disappears.”
A lot of BC’s houses start looking “used” after fifty years. Passive Houses have a longer lifespan, and it should be possible to improve the performance of most buildings.
Rob did not want to give a percentage, instead saying they should be studied on a case by case basis.
He and his son Mark are currently building a six unit strata building in North Park, within walking distance of Victoria’s downtown core.