The residential application of a roof or wall that is alive with vegetation has long been too daunting a proposition for most British Columbia homeowners. But things may be changing.
The idea of a green roof is nothing new. In Europe, they've been deliberately growing vegetation on their rooftops for centuries.
Big commercial projects such as Paris's Musée du Quai Branly has taken the idea to an avant-garde, vertical extreme, with the building's façade covered in a lush 8,600 sq. ft. carpet of plants.
B.C. is just now catching up with this growing trend. Over the last year or so, there's been a sudden surge of interest that's meant a new market for the companies that supply the systems for rooftop gardens.
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In Sechelt, the luxury Wakefield Beach homes project is believed to be the largest residential green roof project in North America. It's comprised of 31 airy, west coast homes, and that's just phase 1.
Elevated Landscape Technologies representative Laura Barker says the residential green roof is a new aspect of their business throughout Canada.
"We are just starting to do them," says Ms. Barker, on the phone from company headquarters in Brantford, Ont. "We did our first certification [in B.C.] and we've got 10 installers out there doing them.
"It's been in Europe for so many years and Canada is finally getting on the bandwagon," she adds. "The city of Toronto did an initiative to get people to do green roofs, and I think that has woken up the rest of the country."
Germany-based Xero Flor Canada has five residential projects in B.C. currently on the line. The company sees the demand for green roofs particularly on the Gulf Islands, where they make a point of using local vegetation.
"It's really interesting to see a shift happening," says west coast representative Genevieve Noel. "Definitely people were always excited about it a few years back, but they weren't willing to pay for it. But now I find people are more willing to put the money forward and invest in something like that."
Bear in mind that this isn't a case of growing moss on your roof or ivy on your walls. A green roof requires a carefully engineered system comprised of a waterproof membrane that is designed to both contain moisture for the plants and prevent it from entering the building. The multi-layered system is added onto the existing roof, with the top layer comprising an inch or more of soil-type "growth media."
When Scott Hawthorn renovated the Gastown building that is home to his Blood Alley restaurant Salt, as well as his large upstairs living space, he opted for a green roof. He had his 3,500 sq. ft. roof installed a year ago for about $28,000 - not cheap, but reasonable if it lasts twice as long as a conventional roof. (A typical residential roof simply blanketed with one type of low-maintenance plant would cost about $12 to $15 per square foot, according to one landscape company.) As a rule, Mr. Hawthorn likes to step outside the box, whether it's a sedum-covered roof or a restaurant that enters off a sometimes vagrant-occupied alleyway.
"I always like to do stuff that hasn't been done before," says Mr. Hawthorn, a former investment banker who now seeks out creative real estate projects in Gastown.
"And it's just something I thought would be nice to have, because it's environmentally the right thing to do and it has a lot of benefits. It deadens sound, and it manages rainwater run-off. Inside, it's cooler too."
Mr. Hawthorn's green rooftop is only accessible by ladder, or by peering over from the neighbouring retail space rooftop that belongs to Inform Interiors (which has its own grass roof). Because it's not meant for access, Mr. Hawthorn's roof is covered in the small succulents that flower on and off throughout the year, but look patchy and scrubby during drier periods.
Eunhee Cha's penthouse green roof, on the other hand, was intended as an extension of her home environment when she had it installed three years ago.
It was designed by Kathryn Friesen, owner of Bloomsbury Designer Gardens, who says the green roof membrane has a lifespan of approximately 30 to 45 years, which is two to three times longer than the conventional roof. Proponents say the green roof lasts because it is protected from UV rays and constant contracting caused by climate. It acts as an extra layer of insulation, cooling the house in summer, warming it in winter. An environmental benefit is that it doesn't contribute to the "heat island" effect of concrete and asphalt rooftops. As well, unlike a hard surface, it absorbs run-off that would otherwise head to the storm drain.
Another benefit is its aesthetic value. Ms. Cha's green roof Japanese garden includes container plants, and is made up of Japanese maples, azaleas, lilies, ferns and bamboo. It resembles a garden she might enjoy at ground level.
Ms. Cha works at the Vancouver International Film Festival, and at this time of year, the pace is intense. Her green roof is like therapy because she can view its tranquillity through large picture windows.
"When people come to my apartment, the first thing they notice is the garden," Ms. Cha says. "It's an extension of my living room -- and you feel like you're living in a house instead of an apartment."
Preparation and proper installation is key to the success of a green roof, say the experts. The green roof is pre-grown so that the plants are established by the time it is installed. The special soil-type media that is used reduces compacting and weeds, and plants are slow growing, hardy ones, intended to last. In Europe, there are green roofs more than 30 years old.
"There is ongoing maintenance," cautions Ms. Friesen. "You cannot just plant a garden like you placed a sofa and walk away."
There are obstacles, too. Ms. Cha faced reluctance from strata council members, who worried about drainage problems. Insurance companies are often reluctant, too. (The insurance industry is in the process of reviewing green roof guidelines). Ms. Cha even had to bring in an engineer to assess the project.
"It was expensive," she says. "But it was worth it."
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