Getting Greenery on Top

Green space is having a hard time getting off the ground and onto Kitchener-Waterloo’s rooftops.

A German contractor named H. Koch pioneered green roofing after he tried to create a fire resistant rooftop with sand and gravel, in between which seeds fell. In the 1960s Germans began to vegetate rooftops for the purpose of rainfall absorption.

Closer to home, for over a decade University of Waterloo researchers have studied green roofs with a project set on top of Waterloo city hall, which holds the largest and highest greenspace in the tri-cities.

Rooftop greenspaces insulate the buildings below, and absorb less light from the sun. This lowers the cost of heating and cooling, while the plants and bedding protect the roof and extend its life. Plants store contaminants from rainfall runoff and filter dust and particulate matter from the air.

According to proponents, rooftop greenspaces also improve a city’s urban aesthetics.

At Waterloo city hall, one can view the green roof within a ropelined “safe area.” When city hall was planned, rooftop greenspace was not something the architects foresaw. Now, security and facility members are extremely careful about the weight the roof is upholding at any time.

Grand River Regional Cancer Centre has one of this city’s only liveable greenspaces. It is located in the heart of their cancer ward and is available as a retreat for patients undergoing intensive care.

As a patient, to see and hear the sounds and colours of a garden while undergoing experiences of weakness and fatigue is essential for healing. But why must we be receiving medical attention before we surround ourselves with the right foliage?

The Perimeter Institute has a green roof, as well as a small garden above their Black Hole Bistro. Sage and calendula grow amongst shrubbery and other herbs the bistro uses in its kitchen. Here physicists and staff can consider quantum relations amongst earth’s green lifeforms.

When the KPL’s Main branch was undergoing renovations their goal was to become a Gold LEED certified building, and visitors to the teen and local history sections on the second floor can now sit next to a green rooftop. The architects designed green space onto this roof, its courtyard and outdoor-columns that shade the building and swirl vines that block the sun’s glare from computer screens.

Rooftop greenspaces on Gold LEED buildings must be self-sustaining in two years. To that end, the KPL project engineers installed a hose bib next to their green roof, but it will have to be removed next year — for the KPL to maintain their building’s sustainability platform, the plants must end up relying only on rainfall, a standard set by LEED.

The building division at the City of Kitchener shared that they have never been asked how a commercial building could create greenspace. Tom Weishar works in the building division and suggests that once one commercial building on King Street undergoes the process of creating a green roof, other buildings can follow suit with ease. He says that newer buildings, which have been overdesigned, support loads easier than older buildings.

However, so long as the process to obtain a building permit for a green or liveable rooftop space remains expensive and uncharted, our city centres will keep developing into urban heat islands.