Retrofit Your Building With a Green Roof
By Cristina Senjug, Partnership Manager, Next Level Stormwater Management
Homeowners Can Shape the Future,
Build Resiliency
When we talk about building a more resilient, sustainable city, it’s easy to picture large infrastructure projects or sweeping policy changes. But some of the most powerful climate solutions are within reach of homeowners, right now. A green roof is a simple yet transformative step you can take, turning the space atop the home you already own into living, breathing green infrastructure.
Transformed for Climate Resilience
In dense urban centres like Toronto and Vancouver, every square metre of green space counts. One of the most inspiring things about green roofs is that they’re not limited to new construction. Many existing buildings, from single-family homes to commercial properties, can be retrofitted to support a green roof. With the right design and structural assessment, your current roof can become a thriving ecosystem. Next Level Stormwater Management has a variety of green roof systems to choose from to suit your structure and design goals. Most popular is our lightweight, economical LiteN’Less® system which is easy, quick and clean to install and maintain. Often, BioBerms® with additional native plants can be added to this soilless system.
Whether it’s the extensive, soilless system or an intensive biodiverse system such as the Alpine Meadow or Flora Garden, all of NLSM’s green roofs provide a basket of benefits that will increase your daily enjoyment, property value and contribute to a healthier and more resilient environment.
Real Impact of a Green roof on Your Home:
- Stormwater Management: Green roofs soak up rainfall and reduce runoff that can overwhelm storm sewers. During heavy storms, this makes a measurable difference
- Flood Mitigation: By slowing and retaining water, green roofs help prevent the flash flooding that’s becoming more common with climate change and can affect your property
- Longer roof lifespan: Protection from UV exposure and temperature extremes can significantly extend roofing membrane life and save you money
- Improved Urban Biodiversity: Pollinators and birds all benefit from pockets of habitat high above the street. A single green roof can become a stepping stone in a larger ecological network
- Improved Air Quality Green roofs help filter pollutants
- Enhanced Aesthetic: Green roofs transform bare rooftops into living landscapes bringing colour, texture, seasonal change, and a direct, calming connection to nature into everyday urban life
What Do I Need to Know?
Can my roof support it?
Many homes can, but a structural assessment is required, especially for older roofs.
What roof slope is allowed?
Green roofs work best on flat to moderately sloped roofs (typically up to ~20° with stabilization).
Can it go over asphalt shingles?
No, a green roof cannot go on asphalt shingles because shingles contain many penetrations, degrade when constantly wet, and are not root‑resistant. Green roofs require a tightly sealed membrane system compatible with root‑barrier layers.
Will it leak?
No, it will not leak if installed over a water-tight waterproofing and root‑barrier system that prevent leaks.
What plants are used?
Sedums, native grasses, and drought‑tolerant plants that thrive in shallow soil and harsh conditions are most common. Rooftop food production is also possible with the right growing media and if the structure can support the extra weight.
Will it attract pests?
No. A well‑designed green roofs does not attract pests and often support beneficial insects.
What are the costs and maintenance?
Costs vary by plantings, size of green roof and ease of access. Maintenance involves routine inspections and weeding.
TO Wants You To Go Green
If you’re in Toronto, the City will support your retrofit through the Eco-Roof Incentive Program.
Toronto’s Green Roof Rebate helps you build your home’s resiliency while helping the city reach its climate and sustainability goals.
To learn more on how to navigate and apply for the rebate, read NLSM’s blog.
Vancouver’s Practical Green Roof Guide
Next Level can walk you through Vancouver’s practical Rain City Green Roof Best Practices Guide that supports homeowners interested in implementing green roofs to help manage rainwater on site, to improve building resilience, and support urban biodiversity.
Vancouver encourages voluntary green roofs by offering design tools, plant lists, and real‑world examples that make it easier for homeowners to plan and build high‑performing systems with confidence.
Read NLSM’s blog with highlights on Vancouver’s Rain City Green Roof Best Practices Guide.
Your Roof – Part of the Climate Solution
Let’s help your green roof grow! Ready to explore what a green roof could look like on your building? The Next Level Stormwater Management team is here to help you take the next step.
Supplier of more than 2.5 Million SQFT Coast-to-Coast
Next Level Stormwater Management (NLSM) is Canada’s leading supplier of high performance rooftop retention and detention solutions such as LiteN’Less™, StormCap™, Alpine Meadow and SpongeBase™. NLSM’s team has more than 90 years of combined industry experience and service. Contact NLSM by email or phone (416) 637-5772.