Embodied vs Operational Carbon: Why We Must Tackle Both
When assessing a building or infrastructure project’s carbon footprint, there are two sides of the coin: embodied carbon and operational carbon. Both contribute to climate impacts, and both demand attention. Here’s an in-depth look at each, why they’re equally important, and how new guidelines and tools are shaping industry practice.
Defining Embodied vs Operational Carbon
Operational Carbon refers to greenhouse gas emissions associated with running a built asset. This includes energy used for heating, ventilation, air conditioning (HVAC), lighting, appliances, and other building systems during its use phase. These emissions occur continuously year-on-year. They are typically measured via energy consumption and are the focus of rating tools like NABERS Energy (National Australian Built Environment Rating System), which benchmarks a building’s operational efficiency. Since its launch in the late 1990s, NABERS has helped Australian buildings save approximately 9.9 million tonnes of CO₂ over the last two decades – a testament to how much operational improvements (like better insulation, efficient chillers, LED lighting, etc.) can reduce emissions. In fact, today around 78% of Australia’s office space is NABERS-rated, reflecting how mainstream managing operational carbon has become.
Embodied Carbon, on the other hand, encompasses the one-time emissions associated with constructing the asset. It’s often described as the “cradle-to-gate” or “upfront” carbon: all the CO₂ emitted in extracting raw materials, manufacturing building products (cement, steel, glass, etc.), transporting them, and the construction processes on site. It can also include lifecycle stages like maintenance, repair, and end-of-life disposal, but the bulk is usually upfront during construction (often labeled stages A1-A5 in lifecycle assessment). Unlike operational carbon which accumulates over decades, embodied carbon is largely expended before a building opens its doors. Traditionally, these emissions were hidden in supply chains and not measured by project teams. However, with growing awareness, embodied carbon is now quantifiable using lifecycle assessment tools, environmental product declarations (EPDs) from manufacturers, and emerging databases that estimate carbon per unit of material.
In summary: operational carbon = emissions to use the building; embodied carbon = emissions to build the building. They are measured in the same units (usually tonnes of CO₂-equivalent) but occur at different times and require different mitigation strategies.
Why Address Both? The Case for a Dual Focus
For years, the industry’s carbon-reduction efforts centered on operational emissions – and rightly so. Operational energy use was massive, and improvements here were low-hanging fruit that delivered cost savings. Programs like NABERS show what’s possible: in buildings that have consistently participated in NABERS, energy use has dropped ~40% on average over 10 years. Operational carbon in commercial buildings is declining thanks to efficiency gains and Australia’s greener electricity grid.
However, as operational footprints shrink, embodied carbon now looms larger in proportion. A key finding from government and industry research is that embodied or “upfront” carbon could represent as much as 85% of a building’s total carbon emissions by 2050 if we continue to decarbonise operational energy. In other words, the cleaner our grid and buildings become, the more the emissions from making construction materials dominate the lifecycle. Ignoring embodied carbon would leave a huge blind spot in our path to net zero.
Another reason architects and engineers must tackle both is to avoid carbon trade-offs. For example, heavily glazing a building might reduce lighting energy (operational benefit) but could raise the embodied carbon significantly due to glass and aluminum production. Conversely, using a very low-carbon material that leads to a less energy-efficient envelope could hurt operational performance. The optimal solution finds a balance – perhaps a design tweak that uses materials smartly without compromising efficiency. This balance can only be found when both embodied and operational carbon are accounted for side-by-side in design decisions.
Finally, policy and client expectations are evolving: Green building certifications and government mandates are expanding their scope. Investors with ESG targets are asking for both operational and embodied carbon metrics. In short, addressing both halves of carbon emissions is becoming part of standard due diligence in design and construction.
New Guidelines: Measuring Embodied Carbon
For a long time, operational carbon had clear metrics (like kWh/m²) and was regulated (energy codes, NABERS, etc.), whereas embodied carbon lacked standard frameworks. That gap is closing. A major development is the introduction of formal guidelines and policies that require embodied carbon measurement:
Infrastructure NSW’s Decarbonising Infrastructure Delivery Policy (2022) – This NSW government policy now mandates the calculation of embodied carbon for new infrastructure projects. As of 2023, business cases for major projects must include an embodied carbon estimate and strategies to reduce it. In April 2024, Infrastructure NSW released detailed Technical Guidelines to standardise how teams measure and report these emissions. This means on roads, rail lines, hospitals, etc., contractors and designers need to quantify the CO₂ from concrete, steel, asphalt, and so on. It’s a shift towards lifecycle carbon accountability in public works.
Green Building Certifications – Green Star (Australia’s green building rating) introduced credits for upfront carbon reduction in its latest version. Internationally, standards like BREEAM and LEED are also incorporating embodied carbon accounting. In some European cities (e.g. London, Amsterdam), there are already regulations setting carbon limits per m² for new construction. Australia is heading in that direction, starting with government-led projects.
NABERS Embodied Carbon Tool – Recognising industry need, NABERS (traditionally focused on operational performance) is developing a framework to measure and benchmark embodied carbon in new buildings. A pilot program has engaged over 150 professionals to shape this tool. The intent is to provide a trusted, nationally consistent way to rate the carbon intensity of construction – analogous to how NABERS Energy rates operational efficiency. While still in development, its anticipated launch will likely set voluntary benchmarks that could become future standards.
All these guidelines underscore: measuring embodied carbon is becoming as routine as counting kilowatt-hours. For architects and engineers, this means it’s time to get fluent in terms like “A1-A5 emissions” (the production and construction stages) and to start requesting carbon data from suppliers. The presence of clear policies also helps – it creates a level playing field where all bidders know upfront carbon matters and can innovate to reduce it.
Strategies to Reduce Both Embodied and Operational Carbon
Addressing both carbon types doesn’t have to be overwhelming. Here are some best practices and emerging strategies:
Early Stage Carbon Modeling: Just as energy modelling is done in design, teams now perform embodied carbon calculations during concept design. By estimating the carbon of different structural systems or facades, designers can choose lower-carbon options upfront. For instance, comparing a post-tensioned concrete frame vs. a steel frame in terms of embodied CO₂ might steer the decision if one has a significantly smaller footprint.
Material Innovation: Embrace low-carbon materials. Examples: use supplementary cementitious materials (SCM) in concrete (fly ash, slag) to reduce cement content (each tonne of ordinary Portland cement emits ~0.8 tonne CO₂). Specify 100% recycled steel rebar. Explore engineered timber for suitable parts of the structure – not only is its production lower carbon, it can sequester carbon during growth. New products like Green Star-certified low-carbon concrete mixes or geopolymer concrete are readily available and can cut concrete emissions by 30-50% with little performance difference. These choices directly shave down embodied carbon.
Efficient Design & Right-sizing: Reducing material quantities through smart design also cuts embodied carbon. Engineering optimisation (e.g., using advanced analysis to avoid over-conservatism) can lead to using less steel or concrete without compromising safety. Modular construction and prefab can reduce waste (thus saving the carbon that would have been emitted making surplus materials). Design for durability so that major elements don’t need frequent replacement or repair.
Renewable Energy Integration: For operational carbon, ensure the design is solar-ready – most large rooftops or carpark structures can host solar panels which directly offset grid energy use. Battery storage can further maximise use of on-site solar. Also consider solar hot water or heat pump systems to displace gas heating. Australia’s sunny climate is an opportunity to embed renewables on buildings, cutting operational emissions for decades to come.
High-Performance Envelope and Systems: Aim for beyond-code energy performance. Ideas: high-efficiency HVAC equipment, smart controls like CO₂ sensors to modulate fresh air, LED lighting with daylight and occupancy sensors, premium insulation and glazing to minimise heating/cooling loads. Many new buildings now go for a NABERS Energy rating of 5.5 or 6 stars (market-leading) – achievable with these measures. That level of efficiency often equates to 50-70% less energy use than an average performer, massively reducing operational CO₂ year after year.
Lifecycle Thinking: Consider the whole lifespan. For embodied carbon: how will components be maintained or replaced? (Choose longer-life materials for high-impact elements; design in modular components that can be swapped easily.) For operational: how might usage change? (Ensure flexibility so the building can be retrofitted for new uses rather than demolished and rebuilt, avoiding future embodied emissions.) Adopt circular economy principles: can materials be reused from other sites, or can your waste materials become someone else’s supply?
Offset Smartly if Needed: After doing all one can to reduce both types of emissions, offsets can neutralise the remainder. This might involve purchasing high-quality carbon credits (e.g., reforestation or renewable energy projects) to claim a net-zero construction or operation. For example, some projects are now delivering “carbon neutral construction” by calculating all embodied emissions and then offsetting that amount. While not a substitute for reductions, offsets are a tool to handle emissions that are currently unavoidable. Australia’s Climate Active offers carbon neutral certification for buildings in operation, and similar concepts are emerging for construction stages.
Throughout these strategies, it’s crucial that architects and engineers collaborate closely. Structural engineers, services engineers, and architects need to iterate together – an optimised structural design (low embodied carbon) should be paired with an optimised mechanical design (low operational carbon). Sometimes there are trade-offs, but more often there are win-wins (e.g., a well-insulated facade can allow smaller HVAC systems, cutting both embodied and operational loads). By using integrated design processes, the project team can find the sweet spot that minimises total carbon emissions without sacrificing functionality or budget.
Challenges and Opportunities
One challenge in addressing embodied carbon is data availability. Whereas operational energy data is easily measured with meters, embodied carbon data requires transparency in material supply chains. The industry still faces gaps in EPD coverage and sometimes inconsistent calculation methodologies. However, initiatives like the Infrastructure NSW guidelines (April 2024) are helping standardise this, and databases are improving rapidly. As more projects demand carbon info from suppliers, those suppliers are incentivised to provide verified data and innovate to lower their numbers (e.g., cement manufacturers developing lower-clinker formulas).
Another challenge is perceived cost: Will low-carbon materials or extra modelling services increase project cost? In some cases, there could be a small premium (for example, concrete with special additives might cost slightly more, or hiring consultants to do carbon assessments is a new fee). But many strategies for carbon reduction align with cost reduction – using less material through optimisation saves money, and energy efficiency obviously saves operational costs. It’s often about shifting perspective: considering the total life cycle cost rather than just the capital cost. A building that costs 2% more to build but uses 30% less energy will be far cheaper over its lifespan. Many developers and asset owners are coming around to this thinking, especially as green financing (loans with better rates for sustainable projects) becomes more common.
On the opportunity side, focusing on both embodied and operational carbon opens up new innovation avenues. We’re seeing exciting developments: carbon-capture technologies at cement plants, use of graphene to strengthen concrete (allowing less material usage), AI-driven energy management systems in buildings, even alternative materials like mycelium-based insulation. Solving these carbon challenges can spur creativity and differentiation. For design firms and contractors, developing expertise in low-carbon design is becoming a market advantage as clients seek out teams that can deliver sustainable outcomes.
Moreover, by tackling both forms of carbon, the built environment sector significantly contributes to broader climate goals. Buildings account for roughly 25% of Australia’s emissions (when considering both direct and indirect emissions). Slashing this through dual carbon management is pivotal to meeting 2030 and 2050 targets. It’s an area where Australia has shown leadership (like NABERS) and can continue to be a world leader by fully integrating embodied carbon solutions in the coming decade.
QIA’s Carbon Management Planning Service
At Quantum Insights Advisory (QIA), we recognise that achieving net-zero in construction requires a comprehensive approach to both embodied and operational emissions. That’s why we offer a dedicated Carbon Management Planning service to support your projects:
Embodied Carbon Assessments: We provide end-to-end measurement and reporting for upfront carbon emissions (A1–A5 stages) on your project, fully compliant with the latest Infrastructure NSW Policy and Technical Guidelines. By quantifying the carbon “hotspots” in materials and processes, we identify practical strategies to reduce the footprint – from material substitutions to efficient construction methods.
Operational Energy Optimisation: Leveraging tools like NABERS and our in-house expertise, we help design teams forecast operational energy use and push for higher efficiency. We can model different building system options and quantify the long-term carbon and cost savings, ensuring sustainability measures pay off over the building’s life.
Carbon Management Plans (CMP): QIA prepares comprehensive Carbon Management Plans tailored to your project. A CMP outlines targeted actions to cut carbon, timelines for implementation, and alignment with any regulatory requirements (for example, demonstrating how your project meets government mandates for carbon reduction). This becomes a roadmap for contractors, designers, and owners to follow – and a document you can share with stakeholders to showcase your commitment.
Carbon Value Engineering: Our unique approach combines our quantity surveying and carbon expertise to conduct “carbon value engineering” workshops. We evaluate design alternatives not only for cost impact but also carbon impact, helping you find the best-value solution that balances both. It’s about finding that desired balance between cost and carbon without compromising on function or aesthetics.
With QIA’s independent advice, you get the peace of mind that carbon reduction opportunities are rigorously identified and evaluated alongside budget considerations. We bring creativity (e.g., exploring innovative materials) backed by quantitative analysis (with detailed cost and carbon data) to propel your project forward sustainably.
Interested in making your next project low-carbon? Reach out to us to learn how our Carbon Management Planning service can integrate into your project workflow from day one and drive both emissions and cost savings. We’re passionate about helping clients deliver infrastructure and buildings that are fit for the future – financially, and environmentally.
