Toronto study shows big cost savings

A study released early this year in Toronto, Canada, has shown that green roof technology can reap huge cost savings for building owners and the community.
A key finding was that an 8% cover of green roofs over the city would reduce the city’s heat island effect by up to 2 degrees Celsius.

Rapid urbanization around the world has meant that  heat island effects  of cities are becoming significant contributors to global warming.  Compared with nearby rural areas, a city s ambient temperature can be from six to 10 degrees C warmer because of heat absorbed and then released from roadways and buildings.

Cr Joe Pantalone, Deputy Mayor of the City of Toronto, said the study of the benefits of green roofs to Toronto also included:

* Direct energy savings of C$12 million a year in buildings from reduced cooling demand in summer.

* Indirect city-savings at peak load demand of C$80 million a year.

* Reduced levels of carbon dioxide, nitrous oxide, ozone and PM10 particulates and sulphur dioxide   from reduction of  heat island effects  and the trapping of gases and particulates by plants grown on green roofs.

* Reduction of stormwater flows by 12 million cubic metres a year, so that existing drainage infrastructure can cope, and sewage overflow events were less frequent.

* Cost savings of C$79 million a year from reduced capital costs for storm-water management, erosion control and sewer overflows.

Cr Pantalone said the City of Toronto was now encouraging the built-environment industry, especially building owners, to design and implement green roofs.  The City of Toronto was now planning green roof retrofits on many of the city-owned buildings   especially because such retrofits could often be done within existing maintenance budgets, he said.

Other North American municipal governments, especially in Chicago and New York, are finding similar financial and environmental benefits from green roofs.

For further information, contact Geoff Wilson, 07 3411 4524, or 0412 622 779.