Just imagine kicking off your shoes, wriggling your toes between the blades of grass, the fresh smell of flowers and spring air, with the urban noise fading against the sound of chirping birds as you look out over the city skyline. Many would describe this scene as one from a utopian dream when in reality this ideal has already been captured in many large cities across the globe. Chicago in the USA, Manhattan in New York City, Bonn in Germany, Basel in Switzerland, Vancouver in Canada and many others stand out as paragons, with garden roofs being used not only as environmental havens but also as green infrastructure designed to increase the liveability of a city.
The proven benefits of this type of infrastructure increase along with our ability to design and integrate it. The most well-documented benefits are the creation of ecosystem networks, storm water runoff management, improved building insulation, as well as aesthetic enhancement. Prime examples of these benefits are prevalent across the world. The top of Chicago City Hall provides a lush green view amidst harsh blacks and browns. A hospital in Switzerland provides a habitat to fauna and flora that were initially displaced when the building was built. A meadow on top of an architect’s house in London not only increases the lifetime of the waterproof membrane of his roof, but also sets a new standard in energy efficiency as it insulates his home. In the heart of Manhattan, a penthouse is designed with a private garden to increase the property value with a side benefit being the minimisation of storm water runoff.
But what about the less recognised benefits?
Garden roofs effectively insulate a building from extreme temperatures but also from noise pollution. This is true not only within the building itself but also its surrounds as noise gets dispersed instead of reflected. Garden walls, such as the one at an aquarium in Vancouver, provides an even greater opportunity with regards to sound dispersal as the sides of buildings present a greater surface area than that of the roof.
It has also been proven that there are both immense physical and psychological benefits to be unlocked by this roof top use. The creation of viable and accessible natural environments within an urban setting opens up opportunities for people to connect with one another, and further literally creates a healthier environment. An art and exhibition hall in Germany gives visitors the chance to mingle in the presence of nature in the middle of a beautiful city scape. One of the most important benefits being embraced is the strategic investment of food roofs near land uses that may benefit therefrom. Hakutsuru, a sake brewing company in Japan, utilises the roof space of one of their offices to grow rice used in the production process. Through this effective investment in infrastructure, opportunities for job creation, increased product output, food security as well as a decrease in supply costs are unlocked. Last but not least, the visible use of greening stimulates public perception and increases the probability of product uptake. Amidst the hustle and bustle of San Francisco, a bus stop is used to open the eyes of passers-by to the endless sustainability possibilities.
Clockwise: Vancouver, Germany, Japan, San Francisco
Given these inspiring international examples, one cannot help but wonder why we don’t see more of these in the City of Cape Town landscape. Surely the benefits of investing in and integrating these infrastructures into the City are undeniable? With organisations such as Advanced Green Roofs, located in the Wynberg suburb of Cape Town, the possibilities are finally starting to open up. Join me in my next article, “Garden Roofs: Local Realities”, as I explore the realities of Cape Town’s fight for a greener skyline.
Main Source: V. Klinkenborg, Up on the Roof, National Geographic May 2009.