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One of three green roofs at the RBC Head Office, Toronto, ON. Living wall at the McMaster University Health Sciences Centre, Hamilton, ON. Firestone's modular SkyScape Vegetative Roof System installation, Victoria, B.C.; Zinco's sloped green roof assembly at the Bank of Canada, Ottawa, ON. A PR IL 2016 | 23 PHOTOGRAPHY COURTESY VERTICAL LANDSCAPE ARCHITECTS; FIRESTONE BUILDING PRODUCTS; ZINCO CANADA INC. Despite Vancouver's repeated claim to fame of being the greenest city in Canada, Toronto has the most comprehensive green roof plan in North America: its green roof bylaw requires the construction of green roofs on all new residential, com- mercial and institutional construction projects with a gross floor area of more than 2,000 square metres (up to 60 per cent green roof coverage is required). The increasing demand across Canada and a greater understanding of the ben- efits of green roofs has translated into brisk business for companies such as ZinCo Canada Inc., which helped pioneer the development of a wide range of green roofs designed to flourish in any landscape hardness zone. ZinCo recently finished work on a sloped green roof system for the Bank of Canada in Ottawa, which the company's landscape engineer and business manager, Jelle Vonk, describes as "Three triangular roofs coming out of the ground for which we used our interlocking Georaster sloped system; in this case, the roof was actu- ally at ground level and complements the top of an underground parkade." ZinCo's solutions are well known in Toronto, from the 55,000-square-foot green roof on the third, eighth, and 31st floors of the RBC Head Office to the 26,000-square- foot roof of the York Community Centre that also doubles as a rainwater collector and sunlight harvester. "Business in the residential and commercial sectors was great last year and is shaping up to be equally busy this year," says Vonk. However, he suggests that as progressive as Toronto may be, "It's not something we can start taking for granted, since mandatory requirements also mean that a lot of people are compelled to seek the cheapest solution. This is potentially dangerous, as a badly designed and installed green roof can cause many building function prob- lems. In the worst cases it will result in complete failure and most of the plants will die. In less severe cases it will involve higher levels of maintenance on an ongoing basis and over the life of the green roof the cost of maintenance can greatly exceed the installation cost." Ronald Schwenger, principal with Vancouver-based Architek Sustainable Building Products Inc. (SBP) Inc., agrees. "Green roof failure not only means plants dying and an unsightly roof in general, it means drainage problems that can ruin a building's profitability and performance," he says. "Toronto isn't the only city in which people try to get away with using the least expensive options, it's also not unheard of right here in this supposedly green mecca." What's the remedy to this mindset? "I think developers should be legally respon- sible over a certain time period for the buildings they create," says Schwenger, add- ing, "The influence of responsible builders is also a benefit; thank goodness for the Ledcors and EllisDons of the world." Roofing specialists such as the Flynn Group of Companies must also be given credit for advancing the cause of quality systems: Flynn was a founding member of GRHC, which aims to increase the awareness of the economic, social and environ- mental benefits of green roof infrastructure across North America and advance the development of the market for green roof products and services. Additionally, Flynn has been early adopters of training and accreditation for green roof professionals. Schwenger believes cities need to adopt genuine and well-thought-out green programs with informed people running them. "I'm disappointed by the City of Vancouver in this regard," he says. "Getting a permit for a simple rainwater harvest- ing system is nightmarish: we've been trying to do this on behalf of a small project for four months now, only to be told to resubmit new drawings. By contrast, cities like Chicago, Portland and New York in addition to Toronto have far more advanced green policies." As for the clients themselves, a good example of an ideal work relation- ship occurred recently for a waterfront home in North Vancouver that required Architek's services. "We began working with the client's architect right from day one as the building was still being designed," says Schwenger. "This is what all good green roof providers strive for." Still, these issues can perhaps be regarded as growing pains for a sector that, while technically not new, is relatively new to the public eye. In addition to the good news of the proliferation of green roofs in general is the branching out of different types of green installations: specifically, living walls, which began as an esthetic addition to high-end office buildings and is now sought by diverse clients. Jason Rokosh, founder of Vertical Landscape Architects, says that when he got into the business four years ago, peoples' awareness of living walls was "extremely limited and some thought the plants were actually fake." Since then, both aware- ness and his business has increased due to the biophilic movement – planners and designers are integrating living systems such as living walls and green roofs into built forms because nature provides humans with mental and physical health ben- efits. His projects have ranged from residential homes and office lobbies to a wall at McMaster University Health Sciences Centre that is 30-feet tall. As a landscape architect, Rokosh believes that "people naturally gravitate to nature so, when located properly in a building, living walls become unique and won- derful gathering places." As an example, the McMaster living wall is an important design feature that is seen and enjoyed by many people working in the building. It is part of an interior lounge connected to a staff cafeteria and is adjacent to a three- storey stairwell. These larger projects are more complicated and require special safety training for working at heights and suspended access equipment operation for installation and maintenance. "Like any living thing, living walls require ongoing maintenance for success," says Rokosh. "Many of the common problems and misconceptions like bugs can be eliminated with proper design, installation and maintenance. There has been a lot of technological improvements on living wall systems and as is the case with green roofs and most things in life, you get what you pay for." Another misconception about living walls that Alan Darlington, founder of Nedlaw Living Walls, finds himself regularly dispelling is that they are purely an esthetic feature. "Our living walls are in fact functional biofilters that are connected to a building's HVAC system, and they achieve a return on investment by reducing air conditioning costs," he explains. Given that microbes growing in association with plants, on their roots and in the water are what cleans the air, the Nedlaw walls contain a pump that constantly circulates water and nutrients from a reservoir at the base to the top of the wall. The water then trickles down the wall through a porous synthetic root media in which the plants are rooted. Air from the occupied space is actively drawn through the plant wall by the HVAC system and then returned to the occupied space. As the dirty air from the space comes in contact with the growing media, contaminants move into the water phase, where they are broken down by the beneficial microbes. Darlington recently finished installing a system for a commercial building in Port of Spain, Trinidad. "We provided a wall for the interior as well as exterior, and while exterior applications wouldn't work in cold climates they have great poten- tial for industrial zones in warm regions where the air coming into the building is atrocious," he says. Green Roofs & Walls

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