When it’s -30C° outside, it only takes the energy equivalent of running two hair dryers to heat this house.
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Topics:Alberta, bathroom, green kitchen, water conservation, window
Green Home in Alberta
Just when most Canadians are getting hefty heating bills, Dave Spencer and Debbie Wiltshire will have reason to celebrate. Their super-green home has no furnace, so they never get natural gas bills. And in the summer, when most of us face sky-high tabs after blasting the air conditioner, this couple gets a credit on their hydro bill. Built in the small development of EchoHaven in the northwest corner of Calgary, their house was designed to produce as much energy as it consumes, otherwise known as a net-zero home.
As a landscape architect, Spencer has spent 30 years designing parks and open spaces in new communities. “I always wanted to build my own house because what’s on the market is not very well built, especially for our cold winters,” says Spencer, a partner in Echo-Logic Land Corporation, the builder of EchoHaven energy-efficient homes. He and Wiltshire got inspired to build one of Alberta’s greenest homes when they were awarded funding from the Canada Mortgage Housing Corporation’s (CMHC) EQuilibrium initiative (for builders and developers) to help defray the cost of developing sustainable homes with little environmental impact.
Vast south windows provide more than half the home’s heat.
Small, north-facing windows limit heat loss and maximize light.
The home uses minimal energy for heating and cooling thanks to careful planning and construction. “We sited the house to have lots of south-facing windows and very few windows on the north side to improve its efficiency,” says Spencer. The house gets 60 per cent of its heating from passive solar gain through low-emissivity–coated windows; with the lower angle of the sun in winter, they get most of the solar gain in the cold months. The rest of the heat comes from rooftop solar panels that power electric radiant heating panels in the ceiling behind the drywall. The home’s airtight structure, with seven inches of spray foam in interior walls and rigid board insulation on the exterior, helps dramatically reduce the need for heat. And a heat recovery ventilation (HRV) system, which captures 79 per cent of the heat in the indoor air before it’s exhausted, preheats incoming air in winter. “When it’s minus 30 outside, it only takes the energy equivalent of running two hair dryers to heat our whole house,” says Spencer.
The kitchen of Dave Spencer and Debbie Wiltshire features energy-wise appliances, LED lights and recycled glass counters.
A drain-water heat recovery system saves on water heating by capturing heat from water that goes down the drains.
The house has no air conditioner, but stays cool in summer thanks to windows designed to draw cool air from the lower level and vent warm air through the home’s highest point. “We borrowed this chimney effect from building techniques in hot climates,” says Wiltshire, a graphic and interior designer. “We had our hottest summer in Calgary in 30 years, but the house was comfortable and we had no problems sleeping.”
To conserve water, the couple uses low-flow toilets, high-efficiency showerheads and faucets, and a rooftop system for harvesting rainwater. That filtered rainwater is used for flushing toilets and watering the garden, cutting their consumption of treated water by 60 per cent. They also spend less to heat water for showers and dishwashing thanks to a solar-powered thermal system and a drain water heat recovery (DWHR) system, which captures the heat from wastewater.
With energy-efficient LED lights throughout the home, the couple consumes about one-third the electricity that average households use for lighting. The triple-glazed, argon-filled windows fill the house with daylight and keep the space amazingly quiet. “There’s construction going on next door with concrete trucks and excavators, but if we close the windows, we don’t hear a thing,” says Spencer. “After a day running errands around the noisy city, that’s very calming.”
After a year of monitoring, the CMHC recently listed the home with an EnerGuide for Homes rating of 99.2 out of 100—an extremely high rating. But the couple needs to cut their consumption further to reach net-zero energy: in 2011 they used a little more energy (9,430 kWh/year) than they produced (8,872 kWh).
Despite missing net zero for their first year, Spencer and Wiltshire find it hugely rewarding to live in a home with one of the smallest environmental footprints in Alberta. “Initially, building a net-zero house was just another project for me, but I really like the place, and it’s now a home,” says Spencer. “I could never go back to a standard home.”
Is Going Green Worth It?
We did the math to find out. This eco-home cost 25 per cent more to build than a standard home, but uses a fraction of the water and energy. Verdict: The owners are saving thousands every year.
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