Green roof glory
Our rooftop was one big blinding white reflective surface, exposed to all the elements. It was not conducive to social gatherings. We used it to hang up our washing. The prospect of changing this into something we can enjoy and something that will benefit the environment was too good not to contemplate.
Sonia Bednar, resident and body corporate committee chair
38 Westbury St, St Kilda East, Victoria
3 storeys, 23 apartments
1. Retrofitted 646 sqm green roof including decks, lawn, vegie planter boxes and over 470 sqm of native plants
2. Water tanks
3. Composting facilities
4. Bike racks
From the street, the white-painted brick three-storey 1950s block of flats at 38 Westbury St looks pretty similar to its neighbours. But head up the back stairs to the roof and a surprise is in store – a verdant surprise, waving gently in the breeze.
Last year, the owners corporation committee and residents watched with anticipation the installation of their new green roof – 646 square metres of it, covering three-quarters of their roof space. Surrounded by the existing brickwork parapet, the green roof includes two lawn areas, planter boxes for vegies, washing lines, a network of paths and three decks, but most of the space is given over to native plantings. “We wanted a self-sustaining ecosystem,” explains Sonia Bednar, resident and committee chair. “The only non-natives are rosemary and lavender, to attract bees and assist biodiversity.”
Westbury’s green roof project began two years earlier, with an idea from Sonia’s partner. “We formed a Green Roof Committee with like-minded residents. We were lucky the people in our apartment block had so many skills to tap into - collectively we could achieve a lot,” she says. They successfully applied for a $200,000 grant through a State Government program to assist community groups to improve the water cycle, and the project was ‘go’.
A thorough structural assessment of the roof was carried out – the decks are positioned over parts of the roof deemed too weak to support the garden – and a heavy duty waterproof and rootproof membrane was laid. “We wanted this to be a success story into the future, so we paid attention to the structure, membrane and leaks,” says Sonia. They integrated a sophisticated leak detection system that will allow any future leaks in the membrane to be pinpointed to within a few centimetres, avoiding the need to dig up lots of the garden for repairs.
Green roof contractor Fytogreen was employed to lay the substrate, install the watering system and choose and plant the grasses, groundcover and small shrubs that make up the rooftop park. The residents held working bees to help with the myriad smaller jobs like painting.
Nine months on, the garden is thriving. It absorbs rainwater and reduces stormwater runoff, and provides thermal insulation: “It makes an enormous difference to the temperature in our [top floor] apartment,” Sonia says. “We could feel it the day it was laid.” And on top of its environmental and thermal benefits, the green roof is already proving hugely positive socially. “Before, we didn’t have a [sense of] community because we didn’t have a communal space. Now everybody’s up here often,” enthuses Sonia, looking around the garden. It’s a place for relaxing, entertaining friends, and for kids to play; in summer a residents’ outdoor cinema night was held, and there are plans for yoga on the roof.
The residents would like to work out the best way to use the rainwater they collect at ground level to water the garden, and they are talking to the City of Port Phillip about installing solar electricity or maybe hot water. Sonia is also keen to investigate keeping bees.