Today marks the second day of the inaugural three-day conference ‘CitiesAlive World Green Roof Infrastructure Congress’ being held at the Sheraton Centre in downtown Toronto.
Hosted by the City of Toronto in partnership with the World Green Roof Infrastructure Network, the event is the only one of its kind in North America with the purpose of gathering the world’s green infrastructure community together to collaborate and grow in their abilities to address issues facing green roofs and infrastructure on an environmental, social and economic level.
Hundreds of participants in the event, including people in the building design and management sectors as well as government officials and policy makers, find common ground in the fact that cities around the world are facing a climate change crisis. CitiesAlive 2009 focuses on the belief that green roofs, walls and other forms of green infrastructure are part of a viable global solution to climate change.
The objective of the Congress is to raise awareness of the benefits of green roof infrastructure and to expand a market for such through an international exchange of information, education, and accreditation opportunities. In short, participants can learn of the best practices used worldwide and hear of leading edge policy developments, research and designs.
Toronto City Hall Green Roof
Toronto’s City Hall Green Roof will be open for previewing, an undertaking nine years in the making, with the past few weeks seeing workers busily laying pipes for irrigation and planting flat after flat of plants and grasses.
The City Hall Green Roof will become a new park for Toronto, accessible to the public, and complete with pathways, benches, tables and chairs – including a public event space surrounded by three rooftop Kentucky coffee trees. A sanctuary of sorts, reminding us here in the urban jungle that nature still exists.
Dreaming of Your Own Green Roof?
On a much smaller scale, if you own a home and desire your own green rooftop or want to organize a residential building green roof initiative, what should you keep in mind? While it’s always easier to start from the planning stage of a new building, there are ways to convert an existing rooftop into a garden. Three important factors to consider are:
- Weight of vegetation/soil and whether the structure can support it
- Type of vegetation that can survive in the microclimate on your rooftop
- Proper drainage of irrigation water
Engineers are qualified to calculate weight restrictions and ensure the safety of imposing extra weight on a roof by planting a rooftop garden. Don’t just start throwing soil on a roof without ensuring it can handle the extra load.
Think carefully of how you will contain the plants or where the water will go when watering them. As well, some plants are hardier than others and will be able to survive in the harsher unprotected climate on your roof where they will be exposed to strong winds and colder temperatures.
Planting species such as Echinacea, Adams Needle (Yucca), Dwarf Arctic Willow shrub, or Russian Sage are likely to be successful candidates. Take into account that some plants have aggressive root systems and can start growing into crevices in the roof looking for water and may lead to cracking in the structure.
Having a rooftop garden is not only good for the environment, it can help keep the roof insulated, can provide fresh produce to eat, and it creates a natural sanctuary to enjoy – an escape to a place a little closer to heaven.
