How a ‘green’ project could lead to smarter urban design

You would never guess to look at it that the roof garden on York’s “smart” Computer and Engineering Studies Building (CESB) is at the crux of a “green” research project that could revolutionize building design and is creating an international buzz.

Hidden in the eaves and tanks that collect the stormwater runoff underneath the sloped patch of overgrown plants are flow meters, rain gauges, and temperature and soil moisture sensors. The equipment, worth $50,000 and funded by all three levels of government, is feeding data in real time into computers that transfer it instantly onto the Internet Web site of a research consortium called Greenroof Systems Consortium.

This information could be gold for environmental designers, city planners, private industry and homebuilders interested in green technology. Though anecdotal evidence suggests that rooftop gardens do reduce stormwater and improve insulation, there is no hard scientific data to back it up. This project will begin to fill that gap and provide the kind of quantifiable and qualitative data needed to assess the environmental and cost effectiveness of rooftop gardens.

Overseeing the project is environmental engineer Glenn MacMillan, a water management supervisor with Toronto and Region Conservation Authority (TRCA). The authority is a member of the consortium, which also includes researchers from various colleges and universities, including York, Seneca and Ryerson. Its objective is to investigate green technologies like rooftop gardens to address such urban problems as storm runoff, water quality and energy conservation.

As conventional water and energy costs rise, developers may well embrace green technologies if data shows they not only conserve water and energy but are cheaper, suggests York environmental studies Professor Lewis Molot, York’s representative on the consortium. The data collected from York’s rooftop garden and another site in Toronto could be extrapolated to determine water management benefits for entire regions, he says. “We’re looking at green roofs as policy and a viable alternative to other stormwater management practices.”

Funded by the Toronto, Ontario and Canadian governments, this project is not only more comprehensive than others, but also highly accessible. MacMillan is especially excited about the fact that data from sensors is recorded instantly on the Web site and available to anyone who applies for a password. He’s met environmental engineers from across the United States and in Europe who want access to the data. “Everybody wants data for this stuff because very few have the money to set up this kind of equipment. Let’s centralize it and share it when we have it.”

At York, MacMillan is monitoring the runoff from two areas over the CESB’s sloped roof — the garden area (the test area) and the traditional roof surface (the control area) next to it for comparison. The roof was incorporated into the building’s design specifically to reduce stormwater drainage because of limited existing sewer capacity. MacMillan began collecting data in July and will finish next year. But he envisions this as a long-term project — a testing ground for rooftop garden design improvements.

He has already come up with an improvement for York’s rooftop garden. The garden is watered daily with treated water, rain or shine. MacMillan is suggesting the stormwater runoff be recycled to water the garden only when sensors indicate it is needed. And that’s just one little improvement on a “green” technology that could hold the solutions to many urban environmental problems.