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Bold Greenroof Ordinance Passed in B.C.

Downtown Port Coquitlam, British Columbia. The city, pop. 57,000, sits at the confluence of the Fraser and Pitt rivers, about 17 miles northeast of Vancouver.

In 2002, the city of Port Coquitlam, British Columbia created a strategic plan to "establish a long-term direction and guide the city in its planning and decision-making." An outcome of that policy is the Port Coquitlam City Council's adoption of an amendment to its zoning bylaw on December 11, 2006 to require green roofs on buildings larger than 5,000 sq. meters.

"The bylaw amendment went through the standard bylaw amendment process, including introduction, first and second reading, public hearing and adoption," Kim Fowler, MCIP, director of development services for the city, explained to LASN.

Fowler submitted a report to the Community and Economic Development Committee back on Sept. 21, 2006 with the green roof recommendation.

The report, a copy of which was forwarded to LASN, noted: "The primary purpose for the new regulation is to obtain environmental benefits including intercepting and reducing storm water run-off, improving building thermal performance and energy consumption, and reducing the urban heat island effect. Secondary benefits would relate to enhanced views where dwelling units or offices overlook the roofs."

The report noted the financial implications: "The installation cost of a green roof is higher than a traditional roof, however, the lifecycle cost is considered to be competitive by most analyses. The design of a green roof in the initial stages will minimize initial costs to the developer. Over the long term green roofs offer substantial off-setting benefits to the owner including reduced heating and cooling costs. Green roofs reduce the energy required to cool or heat a building leading to significant cost savings. In summer, the green roof protects the building from direct solar heat. In winter, the green roof minimizes heat loss through added insulation on the roof.

"The type of green roofs on large format buildings is typically designed as an 'extensive' green roof, which does not allow for public use and is the least cost solution. If a green roof is designed for public access then costs are considerably higher. Examples of such 'intensive' green roofs are found in many urban high density residential buildings, where the outdoor amenity area is designed as an intensive green roof over the parking podium."

Existing buildings in Port Coquitlam larger than 5,000 sq.m. would become "non-conforming" to the green roof regulation as drafted. Non-conforming provisions of the Local Government Act "allow repair and maintenance, including roof replacement, to existing buildings without being required to conform to the new regulation."

Fowler noted the green roof regulation is "one part of the city's Sustainability Initiative, including our Sustainability Checklist, which uses triple bottom line assessment for all rezoning and development permit applications (which also supports green roofs and all green building technology)." The "triple bottom line" assessment is an equally weighted scoring of environmental, economic and socio-cultural criteria.

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December 6, 2019, 12:45 pm PDT

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