You never know where inspiration will strike. A parking garage in Avignon, France got Sue Sirrs thinking about using plants and flowers as structural elements.
“It was above the market in a downtown square and I was struck by its beauty,” recalls the landscape architect and owner of Outside Planning and Design Studio in Halifax. Instead of concrete blocks, the four-storey garage had a “living roof” teeming with plants and flowers. “Think of what our buildings could do if we chose to engage with them in this way,” she says.
Sirrs has gone on to build living roofs in Atlantic Canada, including one for a surf shack in Newfoundland and one for her own backyard shed. Ensuring the roof becomes a permanent structure, she uses native plants for each project. For her shed, she went with blueberries, bunchberries, teaberries, bracken fern and sweet fern.
She sees numerous applications and benefits for living roofs in residential settings. “It’s an affordable addition to any home,” she says. “It extends the life of your roof because it’s not exposed to UV rays. Our winter and summer is a 60-degree flux, so with a green roof, you limit the range of temperature variation—it acts as a buffer. It also keeps the inside cooler in the summer and warmer in the winter.”
The living roof over her shed captures excess water that had been flooding the backyard. “I had a major flow of storm water from my back lane coming into our yard,” says Sirrs. “Putting a green roof on the shed minimized the storm water runoff—it basically absorbed the water.”
Green roofs can also become green gardens. “It really depends on your light conditions and the orientation of your surface,” Sirrs says. “I coach people to plant what they love. So don’t plant tomatoes if your kids hate tomatoes.” At the moment, ashe’s designing a living roof above a restaurant in Halifax with plants the chef will use in recipes.
She is also experimenting with living walls. This past May, she helped design the largest permanent exterior living wall east of Vancouver at the Nova Scotia Community College in Dartmouth, N.S. She spent two years testing 85 plant species for the project. The east-facing wall has about 7,000 plants, with steel frames holding the plants and soil in place. “The building is exposed to salt spray, frozen fog and lots of wind,” says Sirrs. “It’s really harsh versus somewhere like the [Annapolis] Valley, which would be an easier place because there is more heat.”
Sirrs has a smaller living wall in her backyard, made from old magazine racks (“it’s the $20 version,” she says with a laugh). The lush, green privacy fence grows native ferns, hosta, alpine strawberries and coral bells. “I’m struck by how much cooler it is back there,” she says. “And it looks fantastic. It’s my shaded nook in the back of my yard.