After green roofs, “blue roofs” to fight climate change

You’ve probably heard of green roofs, covered with plants to insulate the building and absorb carbon emissions. If this idea gains popularity in the country, a new concept could also gain momentum: blue roofs.

During storms, this roofing system clever allows rainwater to be accumulated and discharged, in a calculated manner, into reservoirs, reducing the risk of flooding and reducing heating and cooling costs.

Our construction techniques are improving and so, basically, it’s like creating a swimming pool on the roof.

The stored water can then be filtered, treated with ultraviolet light and used for other purposes. It can be used at this time either for irrigation, to supply toilets or certain equipment inside the buildingspecifies the town planner.

Friday, the Conservation Authority of Credit Valleybased in Mississauga, will unveil its own smart blue roof, the first in Canada to meet the standards of theInternational Code Councilan organization that promotes rigorous codes for building safety around the world.

The building can now store up to 40,000 liters of water on its roof and an additional 5,000 liters in its basement tank. This water circulates through several filtration and purification systems.

It is then used to supply its toilets and an equipment and vehicle flushing station, explains Kyle Vander Linden, senior advisor in integrated water management for the Office.

The water could also be used for irrigation and perhaps, eventually, with the appropriate treatment systems, it could be drunk.he says.

The layer of water on the building’s roof also has insulating properties, which reduces heating and cooling needs.

The Conservation Authority project Credit Valley cost about $450,000, funded in part through grants. The Federation of Canadian Municipalities, Intact Financial Corporation and the Region of Peel, among others, participated in the initiative.

It was truly a team effort.says Mr. Vander Linden.

The designer of this blue roof, the consulting firm Enviro-Stewardshas also implemented this technology in its own building in Elmira, a small municipality north of Kitchener, Ontario.

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The firm has also installed a green wall in its offices, irrigated using recovered and purified water. This installation helps absorb carbon emissions and release fresh oxygen.

Enviro-Stewards’ blue roof, equipped with a weather station, can predict the amount of rain that will fall during a storm.

Is the cost worth it?

Beyond the savings made thanks to the blue roof, the president of the firm Enviro-Stewards points out that flooding caused by backed-up stormwater pipes is a leading cause of commercial insurance claims.

Bruce Taylor says the number of flood damage claims doubled in a decade, citing a study by the Intact Center for Climate Adaptation. By controlling runoff, a blue roof can effectively stem the risk of flooding.

Storms are more frequent and more intense than before. Our municipal infrastructures are no longer always capable of managing themhe said.

Mr. Taylor says he is currently working with a door hinge manufacturer to cover his factory with a blue roof. He points out that the City of Guelph, which is also considering implementing such a system, already uses rainwater to clean its buses.

Urban planner Éric Turcotte adds that, in most cases, a blue roof costs less than a green roof, which requires more maintenance and sometimes structural work to be able to support the weight of the garden.

Despite everything, a project that costs hundreds of thousands of dollars can be difficult to finance for many businesses and municipalities, already heavily in debt.

Chrystal Healy of the Business Development Bank of Canada says businesses need to evaluate financing and grant options and calculate the long-term savings associated with these types of initiatives.

There is no miracle solution. We are not saying that everyone should install a blue roof.

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Ms Healy adds that some insurers are considering price reductions when their clients implement solutions, such as a blue roof, which reduce the risk of flooding.

Each company is not in the same place, does not have the same reality, so that’s why we offer varied solutions. We want to meet companies where they are in their journeyshe says.