As governments across Canada have increasingly committed to promoting environmental sustainability and resilience in urban environments, they’re setting their sights on integrating green roofs into building codes and standards.
Also known as living or vegetative roofs, green roofs are covered either partially or entirely with plants and vegetation such as trees, shrubs, succulents, grasses, flowers and herbs.
Toronto, an early adopter, introduced its Green Roof Bylaw in 2009, which has led to more than 1,000 green roofs delivered across the city. Meanwhile, Vancouver is home to Canada’s largest green roof spanning six acres atop of Vancouver Convention Centre’s West Building.
Why more cities are embracing green roofs
The positive impacts of installing green roofs are gaining recognition leading to their rising popularity, particularly as more municipalities seek to incorporate green spaces in areas of growing density.
Energy Efficiency
Green roofs have a cooling effect on environments with heat-absorbing materials like asphalt and concrete. Additional insulation that forms part of green roof systems also help regulate temperatures to reduce energy costs throughout the seasons.
Air Quality
By absorbing pollutants such as smog and carbon dioxide, filtering harmful airborne particles and releasing oxygen, green roofs can make a significant difference in improving air quality in and around the buildings they’re installed on.
Stormwater Management
Green roofs help absorb and store stormwater, thereby reducing runoff and keeping pollutants out of our water sources while reducing the risk of localized flooding.
What green roofs mean for roofing contractors
In response to growing demand, more contractors are adding green roofs into their offerings.
But with this evolution in services, there are new exposures and potential liabilities that are important to understand and address as needed.
Green roofs are constructed of layers, which typically include a root barrier, insulation, a drainage system, a waterproof membrane, a growing medium, and the actual plants and vegetation.
If the layers are not properly installed and sealed, leaks can occur and lead to significant water ingress and rot damage in the building.
Identifying the source of damage and conducting repairs with green roofs can be trickier in comparison to traditional roofs due to the complex layer structure and sensitivity of the living plants. Additionally, the presence of soil, vegetation and water adds substantial weight, and the building structure must already have the load-bearing capacity or be retrofitted to ensure structural integrity and safety.
Building owners should also be informed that post-installation, a maintenance program specifically designed for green roofs must be implemented. Proper maintenance should include regular inspections, irrigation, trimming and weeding, fertilization and debris removal. Doing so not only supports the health and longevity of the roof, but also protects the building from water damage and fire hazards.
Challenges of insuring green roof systems
One of the types of insurance that is most essential for roofing contractors is completed operations. Normally provided under commercial general liability, completed operations covers any bodily injury or property damage that results from work done or services provided.
Currently, securing coverage for contractors who offer design, installation and maintenance of green roofs is difficult. Insurance markets open to it are limited; and among those willing, the information required and expectations for the underwriting process is extensive.
Before offering terms and conditions, insurers may request details on:
- The installation methods used
- Qualifications of installers
- Materials being used for installation
- The manufacturers of materials being used
- Where materials are manufactured
- Warranties provided by the manufacturers, contractors and installers
Insurers also often require ‘rights of recourse against manufacturers’ in a green roof supply agreement. This way the insurer can seek compensation from the manufacturer for a property or liability claim should the green roof cause damage or injury.
Establishing industry standards for green roofs
As of now, there remains a lack of established standards and guidelines for green roofs in many parts of Canada.
The Roofing Contractors Association of British Columbia (RCABC) is changing that with the anticipated introduction of its RoofStar Guarantee for vegetated roof assemblies. It is anticipated this program will launch in November 2024.
RCABC has a longstanding history of developing industry standards, best practices and training. This program will provide third party assurance to building owners that only specific accepted materials are being installed to industry-leading standards and independently reviewed.
Meeting the rigorous requirements to qualify for this program can also empower your insurance broker to approach insurance markets and negotiate the best possible terms for you.
James Klassen, RoofStar Technical Advisor/Claims Examiner, had this to say about the RCABC’s RoofStar Guarantee for vegetated roof assemblies:
“Like all of our guarantees, we are taking a risk-managed approach towards green roofing that brings together member manufacturers, pre-qualified green roof systems, qualified member installers and qualified third-party observers with and an objective, clear and rational standard. So many green roofs fail due to poor design, improper construction and installation, lack of inspections, value-engineered components (particularly the growing media or soil), and lack of maintenance post-completion. Our goal is to reshape this perception by delivering a quality-assured guarantee that supports the health and longevity of green roofs, promotes green roofs as a useful municipal tool for managing stormwater, and highlights the advantages of green roofs to insurance underwriters. Maintenance will not only be a requirement, it will be paid for in advance by the owner for the term of coverage (currently two years).”
Henry Seppala, Client Executive, Commercial Insurance, specializes in providing custom insurance and risk management solutions to roofing contractors across Canada.