There is no silver bullet to tackle the challenges of decarbonising the built environment, but an industry event held across Zoom on Monday heard we may be getting close to an answer.
This year, against the backdrop of the climate crisis and a global pandemic, Monica Richter from WWF and Hudson Worsley and Ben Waters from Presync embarked on a journey to find out how best to deal with the issues of embodied carbon in the construction industry.
They spoke to more than 30 organisations, from building and construction contractors, material suppliers, policy makers, university researchers, and rating scheme bodies, to determine the biggest issues and how to face them.
Presenting their findings on Monday in collaboration with Lendlease, before an audience of more than 300, it was clear from the onset the building industry – responsible for about 38 per cent of the greenhouse gas emissions globally – requires urgent action.
As the event’s MC leading sustainability architect Caroline Pidcock noted, “the solutions are available, the challenges can be tackled and our planet cannot wait any longer. The time is now.”
A system-wide approach is needed, but it starts with government
Funded by the New South Wales Government, the Time is Now: Tackling Embodied Carbon in the Building and Construction Sector report by WWF Australia formed the basis for shaping Monday’s event.
The researchers had already spoken to dozens of industry stakeholders and assembled their key findings.
Driven by the NSW government’s ambitious stage one strategy to deliver a 35 per cent cut in emissions by 2030 – having already aligned itself to the Paris Agreement’s net zero carbon society by 2050 – the researchers found momentum for change was building.
Hudson Worsley, co-founder of Presync, a business focused on technology, innovation and sustainability, stamped investors as the number one driver for action, but government procurement as the “single biggest lever”.
“The challenge of decarbonisation is compounded by the complexity of this ecosystem, the sheer number of moving parts, the number of decision points, and the culture of the construction sector,” he said.
“Collaboration… is a key word that underpins everything that we’ve been doing this year.”
Mr Worsley outlined the critical role governments play in regulation and policy, and as strong influencers. In sending the right messages to the wider sector, “enablers are key,” he said.
Mick O’Flynn, acting executive director of sustainability at NSW Department of Planning Industry and Environment, said the net zero plan is intended to facilitate a whole economy transition, with a clear focus on the economic opportunity decarbonising presents rather than the costs of reducing emissions.
“In the NSW Government we totally recognise that we have a really significant part to play in procurement and in other roles,” he said.
“One of the very many funded initiatives in the plan is a program to accelerate the transition to low emissions building materials.”
The NSW government is the biggest construction customer in the state, wielding enough influence to lead the necessary transition.
As it stands, there is little attention given to embodied carbon, researcher and co-founder of Presync Ben Waters said, and there is limited pressure to innovate, but the government can change that.
“The strongest theme in our research was that government procurement is the key lever for change, particularly in infrastructure projects, but it takes targets embedded into tenders, embedded into contracts to walk the talk,” he said.
“We don’t have a price on carbon… but one of our interviewees commented that there’s enough information, there’s enough local materials available already, the main barrier that we have is resistance to change.”
More innovative materials needed in Australia
Decarbonising the building industry is complex. Construction represents between 10 and 15 per cent of Australian GDP, but also is also a significant contributor to greenhouse gas emissions.
Globally, production of concrete and cement make up eight per cent of total global emissions, equating to roughly the same amount of emissions produced from all the cars in the world.
While the single biggest driver of change to low-carbon materials would be a national carbon price, the report states, “in the absence of such a price, purchasers and industry need to factor in carbon content on all project decisions.”
We need competition and alternatives with materials
Concrete, steel, aluminium and timber were high on the agenda at the event, with the speakers noting that competition between materials should be encouraged and alternatives sought.
Within the concrete industry – dominated by global players and a significant carbon emitter – Australia is “not steering the ship to decarbonisation,” Mr Waters said.
“The steering comes from Europe, there are lower carbon options there, but here (in Australia) we ned to ask for them.”
He said finding a replacement for Portland cement, which is the most common cement around the world, is fundamental to reducing embodied carbon in buildings.
He pointed to geopolymer binders as an alternative material with around one-third the embodied carbon of conventional concrete and one fifth of the weight, leading to flow-on emissions reduction in transport.
Steel needs local alternatives
Steel, Mr Waters said, is another carbon intensive material “although we do have substantial local capability and some control over technology pathways.
“We can get today lower carbon steel from Europe, but it appears in this case that it might be preferable instead to work with local industry on a low carbon pathway to build local capability instead of importing greener stuff,” he said.
He pointed to a recent Grattan Industry Report, which underpinned the potential green steel had to make Australia a “renewable energy superpower”.
Smart design is a smart place to start
“For now, smarter design is a way forward,” Mr Waters said, “along with increased gathering of the recycled steel already in the economy.”
Aluminium can be part of the solution
Despite the large carbon footprint associated with aluminium production, it is one of the few materials with the potential to be part of the solution to the broader national decarbonisation issue.
“It’s a lightweight material with good long-term prospects in the low carbon economy, particularly in transport,” he said.
Unlike other materials, the embodied carbon of aluminium can be reduced with no fundamental process change – the carbon intensity is instead dependent on the source of electricity for the smelting.
“So unlike the other two (materials) where process emissions which are hard to avoid produce most of the carbon, it is really about the electricity,” Mr Waters said.
He added the decarbonisation of Australia’s electricity supply will make a big difference to aluminium’s carbon footprint.
Timber: an excellent replacement
Last year, Lendlease built its second timber building at Barangaroo in central Sydney, constructed with around 1,750 pieces of timber.
Wood structures can be built tighter, with better acoustics and thermal performance, and depending on the supply chain, timber can be carbon negative.
During the research phase of the report, timber was touted as an “excellent” replacement material, but lacked a driver for broad uptake.
Lendlease finds gloomy views
An emerging leader in innovative green builds, Lendlease has delved into eradicating embodied carbon, researching the views of their supply chain to find out why the uptake for low carbon materials has lagged.
“Much of the research is quite gloomy,” Lendlease’s national sustainability manager Ann Austin said, “there are quite a number of barriers.”
Risk, position in the supply chain, a lack of alternative options and putting cost above the perception of embodied carbon were recurring themes.
“The market is really not talking about embodied carbon at all,” she said.
“People aren’t asking for low embodied carbon… and this presents a big barrier because suppliers need to know there is a point to making an investment in innovation.”
Circling back to the notion that there is no silver bullet, Ms Austin said decarbonisation is bolstered by demand.
“And so if you remember one thing from today, perhaps it should be to remember to request low embodied outcomes, all the time,” she said, “regardless of whether you’re an investor, a client, a designer, a structural designer, an engineer or somebody who’s working on the site.”
Establishing a Buyers Alliance
Overwhelming support for an impartial body that can support, advise and connect industry people on the path to decarbonisation has paved the way for the establishment of a Buyers Alliance.
“From the feedback we received at the event on Monday, there was a lot of support for knowledge sharing and establishing common targets for procurement and collaboration,” Monica Richter said.
Taking notes from the Business Renewables Centre Australia, which played a “catalytic” role in the take-up of corporate renewable power purchasing agreements, the report states, “an equivalent body could bring together suppliers, builders, developers, contractors, procurement professionals, engineers and architects, researchers and policy makers to accelerate the adoption of low- and zero-carbon construction materials.”
Ms Richter said a Buyers Alliance could be launched as soon as September, in time for World Green Building Week.