The University of Toronto’s Green Roof Innovation Testing (GRIT) Laboratory is paving the way for in-depth studies of green roof technology.

Earlier this month, the American Society of Landscape Architects (ASLA) crowned the GRIT lab as winner of the Award of Excellence (professional) in the research category for the 2013 Professional and Student Awards. The awards honor the best projects from America and around the world involving public places, parks, urban planning and residential design.

Part of the John H. Daniels Facility of Architecture, Landscape and Design, the GRIT lab was established in 2010 and is a state-of-the-art testing site for environmental performance of green roof technology.

While green roofs are popping up around the globe either in compliance with regulatory measures or to save on energy costs, little is known about them apart from their effectiveness.

“We know in principle that these things work, but can we make them work even better?” said Liat Margolis, the professor leading the lab’s research.

Intensive green roof research

Intensive green roof research

GRIT aims to find the optimal style of green roof for the Toronto area by monitoring its 33 miniature eight-by-four green roof boxes. Each of the test beds has a different plant community, watering schedule and care routine to test which works best for Toronto’s climate. Many of the findings thus far have been astounding. The surface on the roof hit 51 degrees Celsius one afternoon in August, but one miniature green roof was recorded as being more than 20 degrees cooler.

In Toronto, it became a requirement for every new building over 2,000 square metres to have a green roof from January 30, 2010 onwards. Extremely hot summer temperatures are normal in Toronto and the city traps much more hot air than surrounding rural areas. To mitigate the urban heat island effect, creating more effective green roofs seemed a logical path to explore.

The GRIT project responds to the desperate need of large cities to address the heat island effect, biodiversity and storm water management. With such a broad ranging project, results will no doubt be extremely useful in public policy and innovation in the green roof industry.

The 33 green roof test beds and three green walls were constructed from 2010 to 2012 to test the effectiveness of the various roofs, walls, and solar photovoltaic technologies. Equipped with 270 sensors connected to 5,000 feet of wiring, the test area also contains a weather station for recording temperatures, soil quality, water flow, evotranspiration and real time climate data, including temperature and wind collected at five minute intervals.

Interdisciplinary research team

Interdisciplinary research team

The lab is intended as a platform for research across a variety of disciplines including landscape architecture, biology, hydrology and building science, with government agencies, other academic institutions and industry partners also involved.

The research team’s website provides information on the current research and data being collected. A live feed of the roof is available, as are downloadable renderings of the material components, plant species and sensor equipment intended for use by industry, public and government agencies.

As green roofs continue to gain popularity, GRIT Lab’s approach of finding the best conditions for a particular climactic area through intensive diversification and detailed research will undoubtedly be of immense value.

  • While “green” is becoming a new “material” for roofs and walls, it is very important that builders, designers and architects can access to all the information about how they work. It is like with any other material we use in the construction industry; we need to know all its properties and characteristics, to be able to choose the better option to apply for each project.

  • Great initiative and I particularly like the testing of different plant species. It’s important that like any “green” strategy, you can measure the actual impact the green roof is having on a building. Would be interested to view the results!

  • Thank you for the article, but you failed to identify the Web Site you indicated would be such a good source to refer to while learning about it in real time. Toronto is a great place but the weather is far from severe enough to really test the composite system. It is useful and i would hope the university would collaborate with other parts of the Northern Hemisphere to study systems in the Southern USA and western part of Canada and USA. The key is obviously to have organic material that can survive, but it is really the composite system that is the key from the structural, membrane and soil applications that move water and materials to drain and keep the whole system healthy. The front-in cost is the Gorilla in the room and the maintenance cost will drive whether it will work or not. If Toronto is mandating this, i hate to be a building owner or contractor or Architect Designer in 10 years when these systems are going to fail and be replaced. I guess one would litigate and sue the city – Good luck and thanks for article.

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