Green Roofs: Going Green From the Top Down

Looking for a way to help the environment, save some wildlife and add visual charm to your neighborhood? Want to save money doing it? Start at the top and go green – as in a green roof. Unlike the single purpose surfaces usually seen covering our buildings, living roofs are designed to do more than simply give shelter. They:

• help clean up a smoggy environment,
• reduce greenhouse gas emissions,

• cool down a sweltering 'heat island effect',
  
• improve insulation and reduce energy costs,
• soften the unwanted sounds of human activity (i.e. noise pollution),
• absorb storm water runoff which can swamp sewer systems,
• provide a habitat for wildlife,
• and add extra growing and/or amenity space.

Overlooking Bay & King, Toronto, Chris Tyler - WikimediaCommons 

Whew! And that's just for starters.

The benefits of having a green roof so outweigh the burden, the city of Toronto, Canada, has been mandating their use in new construction since 2010. They are the first North American city to adopt such a bylaw .

Not every place needs a legal imperative to green-up their municipalities. A lot of forward thinking communities in the United States have been going green, one rooftop at a time, for a while. Chicago got serious about them in 2001, as part of Mayor Daley's Urban Heat Island Initiative. Today, the Windy City has over 500 green roofs covering more than seven million square feet! Washington DC, Minneapolis MN and Baltimore MD have all followed suit with green-roof-goals of their own. They were all named on non profit Green Roofs For Healthy Cities North America's 2009 Top Ten Green Roof Cities list.

Chicago City Hall, TonyTheTiger - WikimediaCommons

Wikipedia defines a green roof as a “roof of a building that is partially or completely covered with vegetation and a growing medium, planted over a waterproofing membrane.” They can be divided into three types: intensive, semi-intensive or extensive, with the type being determined by planting depth and required maintenance.

Viking Recreation, Newfoundland, Dylan Kerluk, WikimediaCommons

Building - lower Manhattan, By: Alyson Hurt, Flickr

The use of grasses or shrubs to cover dwellings can be traced back to at least the Middle Ages. L'Anse aux Meadows, Newfoundland is a UNESCO World Heritage site and home to the reconstructed remains of three Norse sod houses, dated 1000 A.D. Today's “new and improved” designs took root in Germany, in the early 1960's. Proving the adage “everything old is [can be made] new again.”

Norway, Velociostrich, WikimediaCommons

The initial costs of setting up an Eco-friendly covering can leave some consumers feeling like they are in over their head. EPA estimates range from $10 to $25 per square foot, depending on the size and style. This money is recouped in time though, with the real payoff being realized in long term performance savings. Portland State University, University of Toronto and Green Roofs For Healthy Cities worked together to develop an energy calculator that can be used to compare the efficacy of different kinds of roofs. Further savings come from improved durability: a properly installed and maintained living roof will last 2-3 times longer than one made with conventional materials.

As charming as they appear, living roofs are not just architectural eye candy. These canopies have a higher purpose. Whether set in a concrete jungle, a suburban enclave, or a country village - covering a corner of a building or encompassing the entire rooftop, great rewards are reaped when we start at the top and go green. Green roofs are a good idea...for everybody.