Tackling embodied carbon for building services

As Scope 3 emissions emerge as the next big obstacle on the road to net zero, new industry initiatives are looking at the way forward for building services.

Until now, businesses have generally focused on Scope 1 and Scope 2 emissions (or operational emissions) when making net zero commitments. Scope 1 covers direct emissions, for example, gas used onsite for heating, or refrigerant leaks from HVAC&R systems. Scope 2 covers the emissions associated with energy used from the grid.

While these are significant, Climateworks says that Scope 3 emissions are actually greater for most businesses. Scope 3 emissions are generated in the wider economy as a result of business activities. For the building and construction sector, this includes the production, transport, refurbishment and end-of-life processing of building materials.

Joint action

The Materials & Embodied Carbon Leaders’ Alliance (MECLA) is a collaboration between the NSW government and more than 100 founding members driving reductions in embodied carbon in the building and construction industry.

When MECLA began in 2021, working groups were formed to look at the most common and highest-volume building materials: steel, cement and aluminium. According to MECLA, globally these industries alone each produce about 7–9 per cent of annual global greenhouse emissions.

This year, MECLA members established a new working group for building services. Although services may not contain as much embodied carbon as the materials above, they are replaced a number of times during a building’s life.

Ceire Kenny is Consultant, Sustainable Futures, Integrated Solutions for Lendlease, and a member of the MECLA working groups for both building services and aluminium. She says that reducing embodied carbon in building services is particularly challenging.

“Building services are complex in nature in terms of the sheer number of materials in them, and the fact that they have very complex jobs to do – heating, cooling, fire protection, lighting, hydraulics – and need to do them well,” says Kenny.

“To make matters more complicated, there is less control over the emissions from the manufacture of the materials that make up building services. With concrete or steel, you are dealing with a much smaller number of material components and usually the suppliers have direct control over the emissions intensity of the products they produce. For example, they own the steel mill and can invest in electric arc furnace (EAF) or hydrogen.

“With building services, however, it’s often your supply chain’s supply chain – or even further back – that has the direct control. This means that the low-embodied-carbon conversation needs to happen with many suppliers from all over a global supply chain, to have an impact on the embodied carbon emissions of the final product.

Adding to this, Kenny says that many of the materials that make up building services are inherently emissions intensive.

“Steel, copper and aluminium require industrial (high temperature) heat in manufacturing and are not easy to transition to traditional renewables such as solar or wind,” she says. “This makes them hard to abate sectors that will need separate decarbonisation plans and technology.”

Lack of data and good and consistent measurement is also a problem.

Finally, Kenny points to a lack of awareness about embodied carbon in building services.

“The focus has historically been on structural elements, as they make up a large portion of a building’s overall embodied carbon,” she says. “However, as these sectors begin to decarbonise, everything that was left in the ‘too hard basket’ makes up a larger portion of remaining emissions. And given the complexity of building services, conversations need to happen now in order to have solutions in the future. Education is key to spreading awareness and driving change.”

Kenny says part of the solution is engaging with the supply chain to demonstrate demand for low-embodied-carbon products.

“With every tender we need to ask for EPDs (environmental product declarations),” she says, “and with every supply chain conversation we need to ask for clarity on what the science-based target is. If they are early on in the journey that’s fine, it’s about building up the understanding and communicating clearly that we will need solutions in coming years.”

Levers for change

Both NABERS and the Green Building Council of Australia (GBCA) are looking at how to incorporate embodied carbon into their ratings systems.

Ivana Brown, Sector Lead, Accelerating Net Zero Buildings for NABERS, says that although embodied emissions in the production of building materials currently represent 16 per cent of emissions from building and construction globally, according to a recent GBCA report, this will increase to almost 85 per cent by 2050.

Brown agrees that reducing embodied carbon will be a challenge.

“Calculating embodied emissions is complicated,” she says, “with a multitude of choices to be made, including what boundaries you set, what emissions data you use, and how building services are calculated as part of that.

“The industry is also highly fragmented in its approach to measuring embodied emissions, so there is no easy way to compare the performance of one building to another. Depending on the assumptions they choose, two qualified professionals can calculate vastly different embodied carbon footprints for the same building. This is a significant barrier.”

To help overcome these challenges, NABERS is developing a framework to measure, verify and benchmark emissions for buildings.

“We are working collaboratively with government and industry members,” says Brown, “to understand the challenges that need to be overcome to drive change at scale. Over the past 20 years, NABERS has proven that ‘What gets measured gets managed’, and the thousands of buildings participating in NABERS have saved energy at what is likely the fastest rate in the world.

“Our goal is to help spark a similar revolution in embodied emissions, to take the fantastic work some industry players are already conducting at a limited scale, and expand this to reach the whole of the built environment.”

NABERS has consulted stakeholders about the initiative. Many signalled a need for transparency.

“Most stakeholders we engaged conveyed the importance for government to help create robust, credible and consistent frameworks, that allow for the embodied carbon of buildings to be measured and compared,” says Brown. “Our industry engagement has told us there is a strong desire for NABERS to play a role in creating a solution for this.”

The GBCA is working with NABERS on its embodied carbon program. Taryn Cornell is Senior Manager – Green Star Strategy and Development at the GBCA and believes the program will help build consensus on how industry addresses the challenges described above. The GBCA is also looking to tackle embodied carbon through its Green Star Future Focus program. According to Cornell, this will seek to transform the supply chain in two ways.

“The first is creating a drive for low-carbon products as part of the Climate Positive Pathway,” she says, “by requiring every project certified under Green Star Buildings to achieve a minimum of a 10 per cent reduction in upfront carbon, through good design choices and lower carbon products.

“The second is through a new definition of responsible products. This definition is applied in four new credits in Green Star Buildings, one of which is Responsible Services. During development we realised that the building services sector was not as mature as other product and material sectors and because of this we worked with CIBSE to adopt TM65 to the Australian market. TM65 is a calculation methodology for embodied carbon in building services being taken up in the UK and we are hoping for the same adoption here.”

The GBCA is also looking to expand its efforts to work with the supply chain in reducing its embodied carbon and become more circular. As part of this project, Katherine Featherstone has been appointed as Senior Manager Products and Materials.

“We’re excited about the future initiatives we’ll be bringing to this space,” says Cornell.

Leave a Reply

Your email address will not be published.