A touch of paradise is as close as your rooftop garden
Above image courtesy of Fytogreen
Many years ago I was driving through the boondocks of the Hawkesbury district west of Sydney when I happened across the sweetest cottage I’ve ever seen. It had a living roof. Colourful flowers covered the entire space and made it appear as if the house had grown out of the wild cottage garden that surrounded it.
People have built rooftop gardens for 6000 years, starting with the ancient Mesopotamians. Then there’s the Hanging Gardens of Babylon, possibly the most famous rooftop garden in history.
Rooftop gardens have become a staple in Australian office and apartment buildings not just as a green escape, but also as a form of natural insulation. The Readers Digest building in Waterloo Street, Sydney, is home to a magnificent oasis with paths winding between mounded gardens and enormous trees that combine to create an air of mystery.
Increasingly though, people are incorporating green roofs into freestanding homes, sheds, garages and carports. They not only insulate, they filter pollution, reduce stormwater runoff and cool the air.
But be warned. There’s a lot more to building a rooftop garden than throwing down some plastic then topping it with soil and planting a few tubs of petunias according to Stuart Tyler of green roof specialist Fytogreen. “We design supply, install and maintain everything above the waterproof membrane,” Stuart says. “We consider how it fits into the building, access to the roof, drainage, access for installation and planting and getting it up and running.
“Plants are a balancing acts between aesthetic of what the client wants and what will best suit the environment as well as the planting depth and we have a botanist as part of the design team to ensure the plants are ecologically sustainable.
“We use light weight soils and shallow rooted plants such as ground covers, succulents and coastal grasses.
While many of us claim to live in our gardens, Stuart says a growing number can say they live under them. “We’ve done a number of domestic projects and I see it a growing market share,” he says. And while the cost of creating a green roof can add to the price of the build, Stuart says a more and more people are aware of the ongoing benefits, which offset the cost of the initial outlay. “If you just build a normal roof it’s cheaper, so it does add to building costs, but it enhances the building value. There’s increasing awareness to pay more for homes that are environmentally friendly. Everybody’s aware of the damage fossil fuel are doing to the planet, but if they can do some thing little it helps, and building a home with a roof garden does a little bit to assist that problem. Many overseas governments have created incentives for developers and builders to include green roofs as the benefits affect more than the building itself but also the wider community. This includes reduced demand on stormwater infrastructure.
“When you have rainwater coming off hard surfaces, it comes off very fast. Governments spend a lot of money to handle storm water runoff. A green roof mitigates that problem immediately. It’s popular in both inner and outer suburbs. With inner suburbs you get high-density living. Often these high-rise towers have gardens on underground car parks and they want breakout spaces higher up in the building. It’s creating a backyard area for many apartment owners. A growing number of private residences are incorporating roof gardens for the aesthetic and to take advantage of their thermal properties.”
While the ideal time to install a roof garden is construction of the building it’s possible to retro fit them with some very charming results such as the cottage café in Alexandria that Fytogreen undertook. “We have installed over the top of corrugated iron,” Stuart says. “We do a lot of construction on ply or fibre cement sheeting. As long as the structure has the ability for load bearing it can be done.
“You need a Development Application from your council. Most councils look at it favourably, while some want to know how the gardens are accessed for maintenance. As an example of a suburban greenroof project go to 38westburystreet.com.au. This is an example of a suburban apartment block owners getting together and building a greenroof. The web page details how they did it.”
So what is the first step? “Get an engineer to sign off that the roof structure can hold the weight,” Stuart advises. “Then get a waterproof consultant to look at the waterproofing that is suitable to have a greenroof installed upon it. Then contact Fytogreen and we can assist from design development through to installation and maintenance.”
More information: fytogreen.com.au