According to Hudson Worsley, chair of Materials and Embodied Carbon Leaders’ Alliance by the mid-century, embodied carbon could make up 85 per cent of a building’s greenhouse gas emissions.
The theme was a focus of a big online event late last month aimed at local government and what they can do to speed up a transition away from that likely scenario.
Worsley said councils had two big levers:
- capital works and procurement policy: infrastructure such as roads, pavements, stormwater, and wastewater, which typically has large, embodied carbon
- planning approval authority: shaping what is built within the LGA
An expert panel addressed an online event of about 450 people to discuss the issue: Panel members were:
- Paul Whelan, the zero carbon operations lead at the City of Melbourne
- Alberto Jimenez, a senior policy officer at the New South Wales government’s Office of Environment and Climate Change
- Dylan Viviers, the national specifications manager at Holcim
- David MacLennan, the chief executive of the City of Vincent
The importance of measurement
City of Melbourne’s Paul Whelan told the audience the strategy should always measurement.
The City of Melbourne had been carbon neutral more than 10 years.
“What we wanted to do in the emissions reduction plan was not just to look at our regular scope 1, 2 and 3, but we wanted to look in each iteration of this emissions reduction plan and add an area of innovation.”
Inspired by the increasing work of the construction sector in addressing its embodied carbon, the city set out to commission a top down embodied carbon footprint report.
“Over the years of managing our operational emissions, we have seen big emissions cuts through things like electrification of assets, a lot of energy efficiency work, electric vehicles, and renewable energy. But really, the embodied carbon of our capital works begins to dwarf our dwindling operational emissions,” Wheelan said.
“With this we were able to say, ‘We’ve been doing great over the last 10 years on carbon management. There’s this other area of carbon that nobody has been measuring, and this is what that liability looks like into the future’.
There are two types of projects when measured from the top down: civil infrastructure and buildings. Both are approached with different interventions.
While a simple material substitution in streetscape projects could achieve significant emission reduction, buildings were more complex.
“Building a new library or a new aquatic centre, the interventions for reducing embodied carbon from those types of projects start at the design phase, and they involve many more decision makers.”
Next was “bottom up measurement”
“We looked at all the infrastructure that had been delivered and we took the top 10 and did a detailed carbon footprint of them. The top 10 broadly fit into five categories; asphalt road, asphalt footpath, bluestone footpath, blue stone kerb and channel and other concrete works.
“These 10 represented about 85 per cent of our civil infrastructure services contract, which was about $95 million over those four years.”
The City council then looked into opportunities for carbon reduction with the goal of dispelling the myth that decarbonising would come at a significant cost.
Queen Victoria Market
An example was the Queen Victoria Market renewal project where low embodied carbon concrete and asphalt was swapped into an existing design. A footprint measurement showed a 38 per cent embodied carbon reduction in concrete and a 20 per cent reduction from the asphalt.
“For the bean counters here, that represented only a 0.2 per cent increase in the total project cost.
“And that was really important for me to make the business case for rolling out at least these two interventions on a much broader scale.”
The City of Vincent
David MacLennan, from the City of Vincent, 3 kilometres north of the Perth CBD, talked about how local councils could promote sustainable outcomes as a regulator.
“In the planning side of things, most state governments have pretty similar planning and development legislation, and local governments are [often] at the pointy end of implementing that planning legislation,” MacLennan said.
Because local government must develop its own planning schemes, policies, and frameworks, he claimed that these were opportunities to drive change to achieve better outcomes.
While the state government has been busy increasing minimum sustainability standards for multi-unit dwellings and apartments, the City of Vincent council introduced environmental sustainability requirements for single and group dwellings.
“This is somewhere that the state governments across Australia and local governments haven’t usually gone into because you’ll immediately start getting into issues and concerns around affordability and whether you are going to make it too expensive for mum and dads to build a new home.
“And we’ve figured out a way to essentially get the outcomes without impacting costs and saving homeowners money over the long term.”
“There is a myth that buildings will cost you more to design in an environmentally sustainable way, and it will take longer, and it’s more complex – there’s a lack of general awareness in the market about what an environmentally sustainable home means the time that you build, and then live in that home, which could be 20 to 30 or more years.”
The other problem, according to MacLennan, was “quiet” state mandated planning policies – especially in Western Australia, making it hard for local government to be consistent with these policies.
The City of Vincent also faced an unique issue – there were many small inner city areas and not many greenfields. Instead, developers are focused on retrofitting new and existing dwellings into confined spaces.
“We’ve seen over the 10 years that homeowners are trying to get as many houses onto those small lots as possible, not leaving any room for green areas, mature trees, or planting new trees. We were concerned about the urban heat island effect and the loss of tree canopy on private property.
“So, we worked closely with a local company called Cerclos to come up with a simple, user-friendly lifecycle assessment for single or group dwellings.”
MacLennan said that while big multimillion-dollar projects can absorb the cost of sustainability consultants to undertake a lifecycle assessment for big construction projects, mum and dad developers and first home builders lack an “easy to use, do it yourself” lifecycle assessment tool to meet requirements around energy and water use.
After a successful trial, which saw big reductions in carbon lifecycles, the tool is now available on the Cerclos website.
According to MacLennan, the city’s next step was to launch an advisory service from its design review panel to assist potential developers in accessing an environmental expert. Developments, which mean environmental sustainability targets will also be fast tracked and access reduced development application fees.
“This is going to save money for people living in those homes, and the process and tools I talked about are infinitely replicable across local councils throughout Australia.”
Decarbonising Transport
New South Wales government’s Alberto Jimenez said the state’s new decarbonising infrastructure delivery roadmap could be the key to helping local governments get its measurement right.
Jimenez explained that the state government had recently engaged a range of government agencies to develop requirements for low carbon concrete and update its specifications to achieve its goals of reaching net zero by 2050.
“My understanding is that there are discussions with infrastructure ministers around the nation, and they aim for this measurement framework and guidance to become national.
“Twelve months ago, we partnered with Arup to develop a project methodology with three NSW government agencies, Water Infrastructure NSW, Health Infrastructure NSW, and Western Parklands City Authority.
“We did a gap analysis on specifications currently used – most councils have standard drawings for drainage, footpath, curbs, and signage – and some councils may also have these specifications.”
According to Jiminez, a standard drawing may outline requirements such as concrete grade or strength but would not include any sustainability requirements such as simple supplementary sedimentation, cementitious materials, or other alternative materials.
“We then drafted specifications that included recommendations for low carbon concrete requirements – with the help of industry, we were hoping that they would reflect current industry capabilities.”
“Not all recommendations were implemented, and it is up to the agency where of these recommendations they wanted to implement.”
Jimenez then echoed Whelan’s sentiment of being prepared when measuring results.
“Before we were engaged executive directors and our leadership teams, we developed guidelines and fact sheets and updated the specifications, so we go into battle with these ready in advance.”
The new briefings for these specifications will continue in January 2024.
More on low carbon concrete
Holcim’s Dylan Viviers, who worked with the City of Brisbane on early engagement with low carbon concrete, said that technology had rapidly improved while most developers would have had bad experiences five to 10 years ago with contractors trying to use low carbon concrete.
“Technical design alone is so far advanced it’s changing every single day,” Viviers said.
The most important, he said, was early engagement and collaboration – and the Brisbane International cycle track project was an example of that.
“The project is on an existing asset, and it’s about reworking that to make it into an international level cycle track, not only for cycling for skating, multipurpose use and to carry on well into the future once the Olympics has passed,” Viviers said.
And the key to good collaboration? An interactive “lunch and learn session” where the council was taken through what low carbon concrete was and how they can “utilise and transform some of the footpath work they were doing”.
Through back and forth brainstorming and collaboration, the two launched into their second face to face meeting where the project engineers, designers and materials used in the concrete were decided.
“We had technical representation on site to make sure the concrete was performing as it should, and it wasn’t holding up schedules. With this specific project, they wanted some really different oxides in the mixes, so we also had to work through that with them. From start to finish, we wanted to make sure the Council was 100 per cent confident, and the contractors knew exactly what they were getting into.”
“It’s quite amazing to go from talking with the Brisbane City Council about the 2032 Olympics, which has a massive focus on sustainability, to actually delivering this project as the first infrastructure project linked to the 2032 Olympics,”
And the City of Brisbane wasn’t the only exemplar. According to Viviers, the company had worked with several councils, such as City of Logan, which restricted the amount of carbon emitted per meter.
“Councils are starting to ask contractors ‘we want an extra price for low carbon concrete, and that’s amazing. All councils should be driving that and asking tenderers to provide that sort of pricing as well as conventional concrete because there’s going to come a time when low carbon concrete is cost neutral with conventional concrete.
“I believe in the not too distant future, it’s going to go the other way, where low carbon concrete is going to be more sustainable.”