Dave Cherry’s green roof cools his house by as much as 50 per cent in the summer.
Developers are resurrecting LeBreton Flats with residences under green roofs, breathing new life into an area lying dormant under layers of debris and graffiti for decades.
Green roofs are roofs covered in a variety of plants that help filter air of carbon dioxide while also reducing the amount of energy needed to heat and cool the buildings.
Neil Malhotra, VP of Claridge Homes, the home building company in charge of constructing LeBreton Flats residences, says that a combination of greenery with stonework that reflects sunlight will be installed on a large percentage of roofs.
Dave Cherry, co-owner of Job Done Construction Ltd, a green roof installation company, says that although the green roofs proposed by Claridge Homes will be beneficial in reducing energy consumption, more economical and environmentally beneficial green roofs are available.
One of the most efficient green roofs in North America is the Canadian War Museum built on LeBreton Flats three years ago. What makes it so efficient is its high density of self-sustaining, grass-like plants over a large area. Cherry explains that in the summer, these kinds of roofs called “extensive green roofs,” can lower energy used for air-conditioning by 50 per cent.
Peter Leduc, spokesman for the museum, says that having green roofs on LeBreton Flats will be a big step forward for Ottawa. “It makes me proud to be in a cutting edge building,” he says.
Leduc has an office overlooking the green roof and makes frequent plane flights over LeBreton Flats. He says, “the building matches the surrounding land . . . having travelled to a few capitals in my life, it’s nice to see such a sheer volume of green space in Ottawa.”
Cherry says that installing more green roofs in Ottawa will reduce the urban heat island effect. When the sun’s energy is stored in asphalt, shingles and tiles typically used in construction of roofs, a thermal mass is created that slowly releases heat throughout the night.
Green roofs absorb the sun’s energy and reduce this effect substantially.
“If all Ottawa residents installed green roofs the city’s temperature would be reduced by two degrees Celsius, that translates to eight per cent savings in energy used in air-conditioning,” says Cherry.
The green roofs being built by Claridge Homes are called “intensive green roofs.” Cherry says that these types of roofs, resembling a typical garden, are less environmentally beneficial and economical and require maintenance.
Intensive green roofs are redeemed in their promotion of psychological wellness, explains Cherry.
Studies have shown that natural landscapes reduce stress and increase performance of students and office workers by up to 12 per cent.
Plants have also been shown to increase feelings of wellness and speed up recovery of individuals suffering illnesses.
“Opening up my bedroom window and seeing the greenery makes me smile,” says Cherry as he grazes his own green roof with the palm of his hand.