Cities are developing a whole world hidden from the sidewalk-level pedestrian.

Rooftop gardens are springing up more often than ever before, and North Vancouver’s newest is just a couple of months away from completion.

The garden, on top of the new Time development, which includes the IGA/Shoppers Drug Mart on Esplanade near Lonsdale Avenue, will give hundreds of future Lower Lonsdale residents a nicer view. But that garden does more than just look pretty.

Mark Vaughan, the West Vancouver landscape architect who worked on the Time project, said the roof was designed to mimic a beach foreshore area.

“Because it’s so close to the ocean, we thought, ‘why not capture a little bit of a sense of a tidal pool or a beach foreshore right here on this deck?'” Vaughan said. Gravel was put in to represent the water, and the grasses represent the beach. Maples and sumacs mimic forest growth around the beach area.

Vaughan said the variety of grasses make that roof particularly spectacular. “These grasses lead into each other and from above create this fantastic mix of colour and texture and style,” he said.

They wanted to capture the essence of West Coast nature, so they took the landforms and rivers and recreated them in areas where nothing else would be otherwise, he explained.

Despite their beauty, rooftop gardens, dubbed ‘green roofs,’ are better known for their environmental benefits. Putting them in replaces concrete surfaces in the city, which reduces rain runoff and creek flooding, preventing washing out of salmon. They can decrease costs of heating and cooling the building, help rooftops last longer and reduce the heating effect of concrete roofs, making cities more livable.

“Before the city developed, it was forest – nice absorbent soil,” said David Hutch, a landscape architect with North Vancouver City. Development means water is not absorbed as readily and can flood creeks. “It causes erosion. It impacts fish – they can’t find refuge and they get blown out,” he said.

Green roofs can also increase usable social space. One project in downtown Vancouver boasts a rooftop basketball court and putting green, and chefs save Vancouver’s Fairmont Waterfront Hotel between $25,000 and $30,000 annually on food costs by growing their own herbs on the roof.

“In an urban area, we can start using roofs as open space,” Hutch said. “There’s a huge social benefit based on providing people access to that green space.”

Although rooftop gardens have been popular since the Babylonians, modern green roof technology was born in Germany in the 1960s, according to Steven Peck, director of Green Roofs for Healthy Cities.

Green roofs differ from rooftop gardens in that plants grow in soil that is actually part of the roof, not in pots that are arranged on the roof. The structural layers of the roof are covered with a waterproof membrane. A drainage layer is put on top, and the soil is spread on the roof.

Planners, architects and developers are still working to better understand the benefits of green roofs, with ongoing research into how to make the growing surface lightweight, bring the cost down and understand how the roof itself works and how it interacts with its environment.

North Vancouver has been on the green roof bandwagon since at least the 1950s, and boasts about 30 green roofs, according to a green roof inventory conducted by the Greater Vancouver Regional District in 2002.

A few of these are “modern” green roofs, according to Richard White, the city’s deputy director of development services, and many more are of the older style. The difference, White said, is fairly significant – newer green roofs, planted with drought-resistant, often native plants and grasses, are designed to maximize environmental benefits. They usually do not need to be watered, and are not accessible to the public. The older style – including the full-blown rooftop garden on the IGA building – also have definite environmental benefits, but are designed primarily to increase usable space and beautify the city.

The Time project site on Esplanade was particularly well-suited to a green roof, Vaughan said, both because of its size and because hundreds of residents in the adjoining condominium towers will be looking straight down on that roof. At 25,000 square feet of rooftop, Vaughan said he expects it to be the largest green roof in North Vancouver City.

Vaughan has considerable experience with green roofs. In fact, he worked with Time project developer Chris Philps on a green roof for the Q building just down the road.

As with the Time project, Vaughan knew that he wanted to create something to simulate the natural, West Coast environment. While the Time building roof was designed to mimic a beach, the Q building roof was modeled after a river.

Vaughan said that the green roof on the Time Project, as well as making environmental sense and improving the cityscape, also made business sense, since it was cheaper than any other style of roof, apart from a traditional tar and gravel one.

“Had it been just a closed-off gravel roof, that would have been the cheapest,” Vaughan said. “But that’s not an acceptable program these days . . . certainly not in the City of North Van – they’re really concerned about their environment there.”

The city is doing a lot of progressive environmental projects, Vaughan said, pointing to re-establishment of native species in Mahon Park and management of the Wagg Creek watershed. The city is considering the installation of a green roof on the new library building, which is part of the Wagg Creek area. Wide-scale popularization of green roofs in the Lower Mainland is hindered, however, by the lack of concrete information about how well they function in this environment, Vaughan said.

“They provide insulation, but is that an argument for having it? Can that cost be recouped? If it can’t, there might be a better way to spend that money for the environment,” he said.

Some of those answers might be coming soon, as the green roof research facility at the British Columbia Institute of Technology (BCIT) starts to collect data this fall. Maureen Connelly, who is spearheading that project, said that she expects that information, coupled with increasing experience and a growing number of success stories, to help encourage more green roofs in the Lower Mainland.

White said the city has an easy time encouraging developers to include green roofs. “It’s somewhat more costly, but overall it’s very marketable so for the most part, property owners are keen to do it,” he said.

Vaughan said he expects many more green roofs in the North Shore area in coming years.

“Everyone, when they see that they can put it (a green roof) in for not much more money, with the environmental benefit, they’re excited about it,” he said.

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NEWS photo Kristin Bradford

In the photo below LANDSCAPE architect Mark Vaughan shows off a rooftop garden that’s part of the Time project, which includes the IGA/Shoppers Drug Mart building on Esplanade near Lonsdale Avenue. This garden is meant to simulate a beach foreshore area, and will be visible from the 265 condominiums that are part of the project.