Scott Kennedy, the principal of Cornerstone Architecture was the speaker for the Multi- family Passive House Adopted to B.C. Construction Techniques session at the North American Passive House Network conference held on Oct. 2 in downtown Vancouver.
Kennedy said, in his opinion, LEED does not deliver desired results, but Passive House techniques deliver long-term benefits. The building that Kennedy retrofit into a passive house is a rental housing property on Skeena and Hastings in Vancouver.
The City of Vancouver rezoning conditions don't include an absolute energy use target and electrical heat is assumed to be delivered by a heat pump, which essentially penalizes the builder, he said. Passive House energy modeling accounts for thermal bridging, actual air leakage, solar gains and shading, ventilation efficiency and occupant loads.
It's a significant improvement, Kennedy said.
Since the project is a rental building, the owner will either have to include energy in rents or meter it, and charge tenants.
The problem is that metering, invoicing and collections is expensive.
The question is, "can we create an all-electric system?" Kennedy said.
Cost savings come from not installing a hydronic heating system, he added.
Condensing dryers and recirculating kitchen hood fans are necessary to adhere to passive house standards, requiring tenant adaptation. Another question, Kennedy said, if whether tenant behavior will affect the building. Europeans have found that if a tenant keeps his windows open in the winter, if will affect his unit, but not the other units in a passive house structure.
The design and execution of a continuous air barrier is one of the largest design and construction challenges, he said. Using Lunos fans to operate in cycling pairs to ventilate spaces has the advantage of no ducts or drops, distributed ventilation and 90 per cent efficiency.
"It's like putting lungs in your building," Kennedy said.
Over ventilation means high energy consumption and tends to dry out air in cold climates. Under ventilation allows for molds and toxins in the air.
The 2015 North American Passive House Network Conference (NAPHN15) is taking place Oct. 1-2 at Hyatt Regency Hotel in Vancouver, B.C. Check back for more blogs, stories and videos from the conference.