The passive house concept is a growing initiative that takes green building standards to a whole new level. Its approach involves constructing buildings with super-insulation, airtightness and solar power to to reduce energy use substantially in a cost-effective way.
A new passive house project on Temperance Street in Saskatoon is nearing completion. Once constructed and approved, it will become Saskatchewan’s first certified passive house. Robin Adair of Green Builder Inc. has been building energy-efficient homes for a number of years, but the Temperance Street project is his first attempt in seeking passive house certification.
“It’s really about climate change,” Adair says. “Building costs are five to 10 per cent higher when you follow passive house criteria, but it will use 90 per cent less energy than a home that follows the current building code. Solar energy will provide approximately 56 per cent of the house’s electrical demands.”
One of the key elements in passive house design is the energy modelling that is carried out prior to undertaking construction. “All the building elements are entered into the model,” Adair explains. “It tells you very accurately what your energy consumption will be.”
Mike Nemeth of Bright Buildings – who has assisted in the engineering and design of the Temperance build – says more people should be aware of the Passive House Planning Package software, available through the Canadian Passive House Institute West. The software contains everything necessary for designing a properly functioning passive house.
The Temperance Street house’s foundation is completely insulated. It sits on and is surrounded by foam insulation. The Larsen truss walls and triple-glazed, passive-house certified windows also contribute to the house’s energy-efficient design.
The construction uses taped plywood to provide a vapour barrier rather than the more common polyethylene sheet. “This is probably the ideal approach,” Nemeth says. “You achieve extreme levels of airtightness, and it’s part of the structural framing. Poly can be airtight, but it requires lots of fine work, and every time you add an electrical plug-in, you break the vapour barrier. With this service cavity, you don’t come into contact with the plywood barrier.”
The home’s airtightness is put to the test twice before it receives passive house certification. The first blower test is conducted after framing, with the second occurring after everything is in place. An R2000-certified house has 1.5 air exchanges per hour. There can’t be more than .6 air exchanges per hour to receive passive-house certification. Adair hopes the Temperance Street duplex, which has gone beyond the minimum requirements, will achieve .2 or .3 air exchanges.
For more information on passive-house practices, visit the Canadian Passive House Institute West website at canphi.ca.
Story Credit: ecofriendlysask.ca
