Alan De Sousa, mayor of Montreal's Saint-Laurent borough, says Quebec's housing authority has to get moving on its promise to publish construction guidelines for green roofs.

De Sousa is concerned that further delays by Quebec's Régie du bâtiment could discourage developers from including green roofs in their plans to the detriment of his borough's environment. 

A green roof is a rooftop garden that incorporates its own drainage system. Green roofs can help boost a city's total greenspace and offset the "heat island" effect produced by parking lots, tar roofs, industrial sectors and other facets of metropolitan centres. 

De Sousa said he has negotiated with developers to ensure that all new construction involves green roofs and he wants the Régie du bâtiment to draft and publish its guidelines before that progress is lost.

Three new additions to the Bois-Franc housing development near the intersection of Cavendish and Henri-Bourassa boulevards are in their final drafting stages, and are set to include green roofs.

"We're doing it because we care about people's health, to be able to keep the temperature down, to retain water, to give people a good environment," De Sousa said.

In June, the Régie du bâtiment announced the formation of a committee to study and release a report on green roofs, but it wouldn't say when it intends to release any guidelines. 

Saint-Laurent's borough council recently passed a resolution to send a letter to the Régie du bâtiment asking them to draft and release their guidelines as quickly as possible.

'We don't want to regulate it to the point where it suffocates green roofs'- Owen Rose, Architect

Approval process long, overly restrictive and expensive

The current National Building Code of Canada does not include guidelines for green roofs — so it's up to each province to come up with rules. 

Owen Rose, an architect and member of the Montreal Urban Ecology Centre, says there have been green roofs built in Montreal for more than two decades, but including them in new buildings is becoming increasingly difficult.

"We are not against regulation ... But we don't want to regulate it to the point where it suffocates green roofs and this is the fear we have now," Rose said. 

According to Rose, developers who want to install green roofs currently have two options: submit to the Régie du bâtiment's exhaustive six-month approval process, or wait for their guidelines to come out and comply with them. 

Based on his experience with the approval process, Rose says Quebec's housing authority has the strictest green roof policies in the world.

"We shouldn't be building green roofs for Florida hurricanes, San Francisco earthquakes and Japanese tsunamis, we're living in Montreal, we have to adapt to our local climate," Rose said. 

In 2013 the City of Montreal released its own guide to building a green roof.

The City has been able to grant some exceptions for the construction of green roofs to certain developments, including buildings that are two storeys and under, residences under nine units, and for small commercial buildings.

But for taller residential buildings like those De Sousa hopes to build in Saint-Laurent, the Régie du bâtiment has the final say.