White roofs being used to cool low-cost housing in Montreal

Two non-profit organizations in Montreal have launched a project to cool down residents of low-cost housing by greening the asphalt spaces around these complexes, and adding white roofs to the buildings. The idea is to reduce the urban heat island effect as well as to provide pleasant green space for the residents.

The three-year project, called “La ville en vert” (city in green), involves 15 consulting engineering companies. The program is partly funded by government, and is being run by the Montreal Urban Ecology Centre, and the Office municipal d’habitation de Montréal. The latter is a non-profit organization formed in 2002 from an association of 15 Island of Montréal municipal housing authorities.

So far the “ville en vert” program has allocated $9 million to install 43,000 cubic metres of white roofs on 49 low-cost housing complexes—representing the equivalent of 26 hockey rinks. White roofs will reflect the sun’s rays and reduce the amount of heat absorbed by the buildings.

The program also involves removing asphalt and replacing it with green space and urban agriculture, such as by adding fruit trees. Workshops are being held with the residents to encourage their participation.

“The complexes’ often run-down exteriors are thus turned into relaxation areas, meeting places and urban oases,” say the program organizers. “These new cool islands also help improve residents’ health by reducing incidences of asthma, fatigue, and cardiovascular and respiratory difficulties during heat waves.”