Sydney is one of the most progressive cities when it comes to rooftop gardens. The expanding trend benefits property owners and the environment while providing a secret oasis in the midst of dense urban sprawl.
The growing population in Australia’s major cities poses a problem for city planners as well as residents seeking to find adequate green space. A rising number of previously desolate urban rooftops are now being put to use as private residential green spaces for relaxation, personal well-being and socialisation.
“There’s no question about the environmental benefits of green roofs but the social benefits are not yet fully explored,” said 360 Degrees landscape architect Daniel Baffsky, who designed the rooftop garden for the M Central building in Pyrmont last year.
“Up on the roof everyone is equal,” said Baffsky, speaking of the social hub he created for the building’s 400 residents which provides a common area for interaction. This provides a huge benefit for urban apartment owners who previously had no place for chance encounters in which they could get to know their neighbours. It also offers a community feel to those living in urban jungles.
Even single family residences are adopting green roofs as an added sanctuary and to reap the environmental benefits. Australian green roof design firm Junglefy says its main market these days is for roof gardens on home extensions.
Nick Williams, University of Melbourne plant ecologist says tough, versatile plants for a rooftop garden are a must so they can survive long periods without being watered and require little maintenance. Plants with a high tolerance to sunlight are also essential.
Appropriate Plants for Rooftop Gardens include spear grass, Alpine tussock grass, pigface, wallaby grass, coastal twin-leaf, kangaroo grass, magenta storksbill, common everlasting and rounded moon-flower.
Sydney’s adoption of the rooftop garden trend helps with the urban heat island effect (UHIE), which sees higher temperatures recorded in cities compared with rural areas due to heat being generated and absorbed by buildings, pavement and vehicles.
Canadian research has shown that if eight per cent of roofs were greened, ambient temperatures could drop by two degrees Celsius. In Melbourne, the UHIE median has been found to be between two and four degrees, and up to seven degrees at certain times of the year. Rooftop gardens are essential in mitigating the detrimental effects of elevated urban temperatures.
As well as mitigating the effects of the UHIE, rooftop gardens have additional environmental benefits. In addition to providing additional green space, green roofs attract wildlife and insects, absorb airborne pollution and filter stormwater run-off. Urban Ecology Australia suggests rooftop gardens improve a building’s insulation and stabilise the temperature through layers of soil that acts as a thermal sink.
Many residential owners add rooftop gardens to benefit from lower energy costs. In buildings with solar panels, rooftop gardens increase the solar panel energy production by helping the panels absorb more effectively by reducing the reflective heat coming off the roof. Green roofs also help to lower the electromagnetic radiation from surrounding buildings.
Homes with green roofs experience lower internal noise levels. Junglefy says rooftop gardens make roofs last up to twice as long as those without by protecting the roof’s inner membrane. An added space for stylish outdoor living boosts property values and rental appeal, offering a quiet sanctuary for those looking for the urban life with the benefits of a rural oasis.
The trend of adding rooftop gardens to Sydney’s expanse of single-family and apartment buildings shows no signs of stopping with the benefits becoming widely known and appreciated by designers, owners and residents alike.