A Joint Venture with SAP

The project is designed to show how sensor-based data collection and connected devices can increase the efficiency of these structures while reducing maintenance costs and effort.

The benefits of replacing a traditional roof with a living green alternative is considerable. Green roofs help to reduce energy costs between 25% and 85%; capture up to 90% of rainwater that falls on them, reducing pressure on aging municipal storm sewer systems; and extend the life of a roof deck by reducing temperature fluctuations and ultraviolet light. They are also more attractive than traditional roofs, offer opportunities to ‘grow local’, and provide habitat for pollinator insects and birds.

However, these benefits can only accrue if a green roof is optimally installed and maintained.

Youbin Zheng, associate professor with the school of environmental science at the University of Guelph, and graduate student Greg Yuristy have been exploring the use of wireless sensors to monitor moisture, nutrients, plant groups and substrate mixes (growing medium), and to control irrigation systems, says Tyler Whale, industry liaison officer with the University of Guelph. “The goal is to create smart green roofs that perform better and require less hands-on maintenance.”

As part of the collaboration between the University and SAP Canada, two pilot smart green roofs have recently been installed in Ontario. The first is on the 3,500-sq.-ft sloped roof of an environmentally friendly passive solar home just south of Drayton. The second is on the 2,000-sq.-ft flat roof at the Guelph headquarters of the Skyline Group.

“Sensors have been place throughout the roofs to capture information about humidity, soil moisture, fire detection, temperature and light levels, and run-off composition – variables that influence the maintenance of a healthy green roof,” says Bob Campagnolo, senior strategic consultant with SAP Canada.

The team aims to install thousands of sensor-based green roofs on a variety of buildings including commercial, residential and industrial, and on flat and sloped roofs. This level of data feedback will allow the university to direct its research based on known performance indicators, says Campagnolo, and provide a broader understanding of the optimization necessary for individual roofs.

In addition to data from sensors, other sources — including weather forecast services — will be used in tandem with predictive analysis to make intelligent decisions such as when to irrigate based on weather patterns and garden moisture levels. Eventually, building owners and managers will be able to access information through the Web, and even monitor and control their roofs remotely using mobile applications, he says.

Residential and commercial building owners are not the only ones than can benefit from smart green roof technology. Many municipalities are increasing the amount of impermeable surfaces within their boundaries. Access to real data from smart green roof research will help urban planners to better understand the impacts of infilling and heat islands (areas significantly warmer than surrounding spaces) within city centres, and help to inform and direct future policy, says Campagnolo.