How a Melbourne shopping centre became the most sustainable in the world
The Burwood Brickworks residential and shopping precinct in Melbourne, which opened over a year ago, has become the first retail centre to achieve the globally-renowned – and difficult – Living Building Challenge (LBC) Petal Certification for sustainability.
The team from Frasers Property Australia who created Brickworks has painstakingly endeavoured to meet the stringent requirements of the LBC through innovative use of energy creation, water treatment, waste minimisation and choice of materials.
Stephen Choi, who joined Frasers as the Living Building Challenge manager, told The Fifth Estate he was proud that such a public space could also be ultra-sustainable.
“[It’s in] a really ordinary suburb, for ordinary people. But you don’t have to do it in the ordinary way,” Mr Choi said.
COVID-19 significantly disrupted the project’s accreditation due to Melbourne’s prolonged lockdowns and other trading interruptions.
While the project now has LBC Petal Certification on the criteria of place, materials, health and happiness, and beauty, the centre will still need to operate and be assessed over a 12-month period on water, energy, and equity to achieve the full LBC certification.
The LBC itself is a dynamic set of challenges for developers, based on the central principle of creating buildings that give back more than they take.
Among a long and evolving list of requirements, buildings must produce more energy than they consume through renewable energy, clean their own water on site and divert a minimum of 99 per cent of waste from landfill during construction.
Having completed the construction component of the challenge, Frasers plans to release a list of over 1000 building products used to make the Brickworks — called the Greensheet — that meet the stringent LBC demands.
Materials of such low impact were extremely difficult and costly for the team to source, however, Frasers Property Australia chief executive Anthony Boyd said the idea of the project was to push the industry as a whole to perform better.
Through the use of 3260 individual roof-mounted solar panels and 250KW battery, Brickworks generates more energy that it consumes even with its many tenants, the largest of which are Woolworths, Dan Murphy’s and even a multiplex cinema.
According to Frasers, achieving the Petal Certification required all of the building’s retail tenants to be on board with the goal and actively cut their energy consumption.
Greater energy efficiency was achieved through the use of LEDs and by focusing on lighting colour and angles as well as requiring sealed refrigeration. All tenants are also connected to a central thermal network, which avoids the use of more inefficient individual systems.
In terms of the building’s structure, its saw-tooth roof windows can open and close depending on the weather.
“If the conditions are nice outside and we do open it up it means that we’re not pumping air conditioning in. Buildings that are completely sealed, even when the conditions are good outside, they’re still using the thermal systems even though they might not necessarily need to. We get to avoid that, for quite a lot of the year actually,” Mr Choi said.
“It’s kind of the opposite to normal shopping design. There was a phase where I think a lot of shopping centre design was very much about making it hard to know what time of day it was and what it was like outside. A bit casino-like I guess – that sort of strategy.”
Materials – probably the most difficult challenge
Because the LBC Petal Certification takes a holistic view on the environmental impact of buildings, using the right materials was a crucial part of achieving the rating.
Mr Choi described it as, “probably the most difficult component of the LBC.”
“It’s like making a cake for someone who’s got every single dietary requirement you can think of,” he said.
All aspects of the materials used was looked at, from where they were sourced to any pollutants they might contain, and developers were required to source salvaged materials where possible.
Tenants, contractors, consultants and suppliers were all required to provide a detailed list of the materials they intended to use for approval.
The team was forced to salvage timber for the build from roughly 25 other locations, including a dismantled pier at Sydney’s Circular Quay and a Melbourne CBD office building which was being demolished.
None of the materials used in the Brickworks contain chemicals on the International Living Future Institute’s Red List, which includes formaldehyde, lead, mercury and PVC.
All of the timber used on the project was Forest Stewardship Council (FSC) certified, which according to Mr Choi is very difficult to come by in Australia, other than softwood.
“If you want hardwood you essentially have to go overseas to get it and that is a real problem for us because, if you imagine shop fitouts there’s just a giant amount of joinery and we wanted a lot of timber cladding in the centre,” he said.
The use of concrete and steel, which have high embodied carbon, was minimised as much as possible.
As well as making the steel for the superstructure as slim as they could to reduce volume, as many mechanical connections as possible were used, for example using a nut and bolt over a weld, to increase the likelihood of reuse.
The project’s total embodied and construction related carbon footprint of roughly 19.5 kilo tonnes will be accounted for through a one-time carbon offset later this year.
Water – another big challenge
Rainwater is captured and treated onsite for use in toilets, washing machines, cooling towers, car-washing and irrigation of the on-site urban agriculture.
While brickworks is capable of capturing and treating all the water required by the building, due to government regulations which stipulate if mains water supply is available it has to be used, the building still uses mains water supply.
“Because we’re such a public building they won’t let us, even if we clean the water to drinking standard, we’re not allowed to give people that water to drink,” Mr Choi said.
The Brickworks also has blackwater treatment facilities.
“We have a sewer and stormwater connection just because it’s the requirement for a shopping centre in suburban Melbourne. But we actually have our own blackwater treatment on site so we can accommodate all the water on the site itself,” Mr Choi said.
The LBC required Brickworks to commit a proportion of its area to food production for use on site. Prompting the developers to create an Australian-first rooftop farm on top of the shopping centre.
Much of the food grown on the chemical-free 2500 square metre farm is used to service an onsite restaurant and cafe, with the rest distributed through community initiatives.
Compost from the retailers helps feed the farm. While a large hydroponic glasshouse produces fruit, vegetables, herbs and flowers.
Having a working farm on the roof of the shopping centre required the building to be tailor suited to that end.
“If you’re not doing a metal-deck roof but you’re putting a farm there a hundred things change and it’s really intrinsic to the building,” Mr Choi said.
The end result however is not only a tight circle of food being grown, eaten on site, and the organic waste being composted to grow more food, but also a major draw for visitors to the centre.
“I think the farm is something a lot of other developers will start taking up, urban agriculture, I think that’s been proven at Brickworks.”
As well as being an engineering and sustainability marvel, Brickworks is a working shopping centre with rent-paying tenants, helping recoup some of the cost of the unorthodox construction.
“This building is just like any of the other shopping centres. It has to make its money back, it’s not a charitable event,” Mr Choi said.
Through planning many of the main components were able to be achieved at normal cost, however, the ambitious large-scale undertakings of on-site water treatment and the rooftop farm were more difficult to make financially viable.
“Those were the two big items that we just never would have done if we didn’t do LBC,” Mr Choi said.
What has been achieved?
Vetting and selecting the materials for the project was an arduous and time-consuming process that resulted in several retailers reformulating their products and releasing them to the market.
“There were lots and lots and lots of products that we just couldn’t use because they hadn’t actually been tested to see what their air quality emissions and human health impacts were,” Mr Choi said.
Some suppliers were willing to go through the testing process with the team, and of those there were many that did not meet the air quality impact standards of the LBC.
Choi said that having more suppliers on board and understanding the requirements of the LBC and making their products meet them would go a long way to making more buildings like Brickworks a reality.
Helping achieve that will also be the Greensheet, to be released by Frasers later in the year.
Other stipulations of achieving LBC accreditation are charitable acts in the form of a half cent donation for every dollar spent on construction, which Fraser opted to partially direct towards a homeless support organisation, and the directive to “protect an area of land equivalent to your own.”
Subsequently, along with a number of other project teams, Fraser has purchased a package of land in Argentina which is of ecological importance and will be spared from development.
“That kind of thing is really nice and eye-opening,” Mr Choi said. “We try to think about what all of that really means and if this is the sort of thing we should be doing more as an industry.”