are Growing Food and Biodiversity
in Cities like Toronto, Washington, and Montreal
first article about green roofs,
published in 1995, the idea has caught on and a whole industry has
developed. And its North American industry association (which has added
green walls to its field of interest) has also grown. Green Roofs for Healthy Cities
(GRHC) says that the industry grew by double-digits in 2016 according to its
2016 Annual Green Roof Industry Survey.
city of Toronto, Ontario had the most square footage of green roofing
installed in 2016, with Chicago, Washington D.C., and Seattle following.
“It’s no small feat that Toronto has been recognized as the leading city for
green roof installation in North America,” says Jennifer Keesmaat, Chief
Planner for the City of Toronto. “Our Green Roof Bylaw, in effect since
2010, has resulted in a new roof-scape for Toronto, cooling the city,
helping to mitigate water run off, while also adding beauty and
According to the
2016 survey, corporate members recorded 889 projects in 40 US states and six
Canadian provinces, installing 4,061,024 square feet of green roofing.
green roof market continues to grow, there is still an enormous potential
for new green roofs to be installed on tens of billions of square feet
across North America. Strong policy support in cities like Washington, D.C.
and Toronto is driving the growth.
In Montreal, Quebec, the largest organic supermarket
green roof garden (25,000 square feet) in Canada has just been unveiled.
It’s also the first in the country to sell its produce in the store. The
project was developed by IGA supermarket owners Famille Duchemin on their
new LEED certified store.
30 different varieties of organic produce certified by Ecocert Canada will
be grown on the supermarket’s roof, including lettuce, peppers, herbs, and
tomatoes. In addition to the vegetable garden, the roof is also home to
eight Alvéole bee hives, set to produce roughly 600 jars of honey to sell.
newspaper reported that the store’s co-owner Richard Duchemin says they
decided to treat a requirement by the Montreal borough of St-Laurent to
install a green roof as an opportunity, instead of a constraint. Montreal
has been working on a policy for green roofs on its larger buildings for a
number of years, with some developers fearing the requirements were too
difficult to meet.
The green roof
at the IGA supermarket plays a role in the LEED certification, reducing energy consumption by
providing an extra layer of insulation. In addition, the garden is irrigated
with water collected from the store’s dehumidification system, which would
otherwise have been discarded, and the roof has become a habitat for birds
Priesnitz is Natural Life Magazine's editor.