On shaping a sustainable future for Sydney – and other cities

The Vivid Ideas Exchange was the perfect opportunity to reflect on how far Australia has come in sustainably designing our built environment, and how to make our cities liveable in a net zero world.

On Wednesday, The Fifth Estate chaired Shaping Sustainable Sydney, a panel discussion part with Craig Baudin from Fender Katsalidis, Tim Phillips from Tilt Industrial Design, Suzie Barnett, the founding chief executive of Junglefy and University of New South Wales associate professor Philip Oldfield.

It feels like the design of our cities is increasingly being shaped by two opposing forces – the need to reduce the carbon footprint, especially embodied carbon, and the desire for cities to bring us closer to nature, so as Barnett put it “We can be less dominating on nature and how we can work within it to create a deeper connection to nature via our built environment”.

Reimagining materials

No discussion involving architects can escape a discussion on materials, which are increasingly labelled “good” (think timber) and “bad” (concrete, steel).

The latest trend involves busting those stereotypes and instead reimagining materials, by making them more sustainable.

Phillips noted a trend towards using aluminium, because more suppliers were offering low-carbon options using recycled product made from renewable electricity. Aluminium is efficient to recycle and uses around 95 per cent less electricity than manufacturing it from raw materials, he said.

Concrete is also coming back into favour, with geopolymer options now available which hardens at room temperature and avoids the use of Portland cement, which produces large amount of CO₂ when it is manufactured, Baudin said.

Timber, which has been overlooked in favour of concrete and steel in modern building designs, is undergoing a resurgence, UNSW’s Oldfield said.

Engineered timber involves several layers of timber laminated to create a stronger product that can be used to construct larger buildings and carry bigger loads. He pointed to International House at Barangaroo and 25 King Street as examples of well-designed modern timber buildings.

Embodied carbon is front of mind for the building design community.

Oldfield said previously we were only concerned with the energy efficiency of a building while it is in operation – lighting, heating, ventilation.

Now that concern has extended to the impact of the materials used in construction. A typical building has around 800 kilograms of embodied carbon per square metre, Oldfield said, adding that the world is building the equivalent of every existing structure in Japan every year. He said returning to building with timber was a way to “build better”.

Returning to nature

But materials can only get us so far – we cannot achieve fully sustainable cities without incorporating a connection to the natural world. This is where biophilic design comes in. “It basically means our, our deep human connection to nature. We are hardwired to be happier in nature, that’s where we came from. So when we think about biophilic, design, that is the integration of the natural elements,the things we love about nature, into the built environment,” Barnett said.

The aim is to achieve a response akin to “going for a bushwalk or a swim in the ocean,” she added. “If we’re happier and healthier, we’re actually more productive. It’s a very compelling business case, in the built environment, particularly for commercial buildings.” Biophilic design could be the drawcard that employers need to lure employees back into the office after working from home during the pandemic.

Good biophilic design involves more than just a few well-positioned pot plants though.

“One of my favourite things to think about with biophilic design is how a space makes you feel,” Barnett said.

“We need nature more than nature needs us – when we’re not here nature will take over. And it’s bringing those elements into our built environment, which I think is now creating the next revolution I think of, of innovation in our built environment.”

Baudin agreed that the pandemic forced a lot of our attention on the spaces we work in.

“People started to think well, I’m going to spend a significant proportion of my life in a workplace. Are these places really the best they can be? There is a fight for talent, a fight to get people back in.”

“What we’re trying to look at is what is the next generation of workplace and how does that connection to biophilia to nature thread through the workplace.

“And it’s things like the ability to get a free desk, to go sit on a terrace with your laptop, to sit outside, but also to connect while you’re indoors like being able to open a window to have natural ventilation”

Unbuilding the future

As Carl Elefante, former president of the American Institute of Architects, put it: “The greenest building is the one that already exists”.

The movement to find new uses for existing buildings is in full swing, and the latest trend is to convert tired commercial buildings in city centres into residential. This is also an opportunity to add lightweight structures to existing buildings, many of which were over-engineered when they were designed in the 1970s  or 1980s.

“Concrete is a huge emissions source. We’ve expended all of these emissions to build these structures, so they’re baked into our cities. If we demolish them and replace them with new structures, we’re wasting that previous expenditure of carbon,” Baudin said.

He points to the Midtown project in Brisbane, which fused two 1970s public service buildings with a new breathing atrium, a larger floor plate, a high-performing façade and updated services. If the buildings were demolished and rebuilt it would have involved 38 per cent more embodied carbon, or the emissions involved in operating the buildings for four years, he added.

Use what we already have

In another project in Melbourne, an existing 22-storey 1990s office building was topped with a new lightweight 14-storey structure.

“You can build 10 storeys on top of a lot of our CBD buildings,” Oldfield said. “That provides us with a fantastic opportunity to densify and intensify our cities with lightweight timber rooftops. We can densify and we can make use of mass timber to increase the floorspace of buildings. And then we can use the additional rent to upgrade the facilities of the building below it. So it’s a win-win for me.”

Baudin and Oldfield cautioned that while some B-grade office towers were suited to a residential conversion, some of the newer campus style buildings with large deep floor plates were less adaptable due to the lack of natural light at the centre of the floor area.

Converting these buildings would involve building windowless rooms, which in Australia are illegal under the National Construction Code (NCC), Oldfield pointed out.

“We’ve just been talking about biophilia, the importance of daylight, the importance of ventilation, the importance of being able to see a plant or some greenery out your window, or some kind of blue sky.

“I also question what happens in a power outage, and on a really hot day. Big trouble,” he added.

Letting go of the Great Australian Dream

Thanks to a federal government tax break for investors, everyone has started talking about Build-to-Rent.

Barnett said it’s a great way to encourage sustainable design because there is one single long-term owner who has a vested interest in having a building that performs efficiently and sustainably.

In the traditional model of developer, builder, strata committee and multiple tenants “things start to get diluted, risks get passed down and people stop caring,” Barnett said.

“I think though the barrier is going to be us, and I think that this concept that we must own rather than lifelong renting, which I think is already accepted in places like Europe and North America,” she added.

“It also fosters innovation – you’ve got someone willing to take a bit more risk to do something more innovative, because they see it as a long-term investment.”

Institutional property owners typically have strict ESG criteria, and so any build-to-rent development will be subject to these, Baudin added.

Policy wish-list

No sustainability discussion involving industry experts would be complete without a wish list for government policy changes or incentives to help accelerate change.

Baudin is looking forward to the New South Wales’ government’s new Sustainable State Environmental Planning Policy (SEPP) due for release in October this year, because it will be among the first policies in Australia to address embodied carbon.

He noted that initially it will be a requirement to measure and manage embodied carbon rather than an outright cap, but it could be ratcheted up in future to apply a maximum amount of embodied carbon per development.

“And that’s, that’s a big deal. That’s not something that’s happening anywhere else in Australia at the moment,” Baudin said, adding that embodied carbon in construction materials accounts for up to 15 per cent of global emissions.”

The NCC is a “dinosaur” in desperate need of an upgrade, Oldfield said.

“Our building regulations are probably 10 years behind many of the developed countries. If you build a house today, you need to get a minimum six-star NatHERS rating.

“And they range from zero, which is basically living outside to 10, which would be a passive house eco house. You’ve got to get six now and it will soon be seven. But the average Australian house is 1.8 stars, out of 10. That’s a failure.

“We need a massive national level retrofit of our existing building stock,” he added.

Oldfield said the NSW Sustainable state environmental planning policy or SEPP is filling in a gap that should be the responsibility of the NCC.

“The building code is a very slow moving dinosaur document that takes forever to move. And I think this is the New South Wales government trying to take an initiative to speed things along and take a bit of a proactive approach. But ultimately, I think carbon measurement should ideally be part of the NCC.”

Policy incentives to encourage adaptive reuse to help densify our cities wouldn’t hurt either, according to Baudin. “A Floor Space Incentive bonus for adaptive reuse would be a really good way to incentivize more density in the inner city, to recognise that you are actually doing a public good.”

Bonuses to encourage builders to use less embodied carbon would also help, said Oldfield. “If you can have half the embodied carbon, you can build an extra 20 per cent in height. It’s a no-brainer.”