Emissions from the built environment are a major topic in the global sustainability discourse. These emissions originate from two main sources: embodied emissions, which are associated with material production and construction, and operational emissions generated during a building’s use. Approximately 11% of the emissions are attributed to embodied carbon. Operational emissions are expected to decrease as renewable energy use and efficiency improve, whereas embodied carbon in construction materials is present from the beginning of a project. Once materials are produced, transported and installed, their carbon footprint is embedded in the building. Conducting an embodied carbon assessment (ECA) during the initial phase of the project contributes significantly to a sustainable construction process. This involves measuring emissions from cradle to gate and beyond. Developers, manufacturers and architects can identify high-impact products, substitute lower-carbon alternatives and set projects on the pathway to compliance with green building regulations.
What is Embodied Carbon?
Embodied carbon refers to all greenhouse gas emissions released throughout the lifecycle of a material. This includes:
- Extraction of raw resources
- Manufacturing and processing of products
- Transportation to construction sites
- Installation, maintenance, and disposal
Unlike operational carbon, which is produced during a building’s use phase (e.g. heating, cooling, lighting), embodied carbon emissions have already been released by the time materials reach the construction site. This means that the carbon footprint is locked in and cannot be changed; it is already part of the atmosphere by the time construction begins. Once chosen, these materials largely determine a project’s long-term footprint.
Learn More: Understand How you Can Reduce Embodied Carbon in Products
The Importance of Assessing Embodied Carbon
Understand the scale of impact: Research from the Rocky Mountain Institute (RMI) indicates that the global building stock is expected to double by 2060. Without adequate intervention, this could result in embodied carbon accounting for nearly half of all new construction emissions by 2050.
Regulatory pressure: The UK’s Net Zero Strategy emphasises whole-life carbon reporting in line with RIBA guidance and PAS 2080. In the EU, the Energy Performance of Buildings Directive (EPBD) is moving towards mandatory whole life cycle carbon disclosure by 2027.
Investor and client demand: Investors increasingly use environmental, social, and governance (ESG) metrics to evaluate project risk. Clients could also demand evidence that developments meet green building certifications such as Building Research Establishment Environmental Assessment Method (BREEAM), Leadership in Energy and Environmental Design (LEED) and Deutsche Gesellschaft für Nachhaltiges Bauen (DGNB), where embodied carbon in construction is a key metric.
Key Sources of Embodied Carbon in Construction Materials
Understanding hotspots helps prioritise reduction strategies.
Cement and Concrete: Concrete is the most widely used construction material worldwide, resulting in a relatively high contribution to embodied carbon. The production of cement, its primary binding agent, is responsible for around 8% of global CO₂ emissions according to data from Certified Energy. This is largely due to the calcination of limestone, which releases CO₂, alongside the heavy use of fossil fuels in kilns.
Learn More: Read our whitepaper on 'Carbon Storage in COncrete through Accelerated Carbonation'
Steel: Essential for reinforcement and structure, steel is highly energy-intensive, relying heavily on fossil fuels. Globally, Certified Energy estimates that steel production accounts for approximately 7–9% of total CO₂ emissions, much of it from coal-powered blast furnaces.
Glass and Aluminium: Frequently used in partitioning and modular, both materials have high carbon footprints due to energy-intensive smelting processes. Aluminium alone has one of the highest embodied carbon footprints of all common construction materials because its production requires electrolysis at extremely high temperatures. Moving to electric arc furnaces powered by renewables and increasing the proportion of recycled scrap aluminium could help reduce emissions.
Insulation and Finishes: Though lighter, plastics, foams and composites can contribute significantly due to their petrochemical origins. One way to reduce embodied carbon in insulation is to consider replacing with natural alternatives like wood fibre.
Conducting an Embodied Carbon Assessment (ECA)
Step 1: Define the goal and scope
At early design stages, cradle-to-gate assessments help steer procurement decisions. Later stages often require cradle-to-grave analysis for full compliance with standards such as PAS 2080 and EN 15978.
- Establish whether the analysis covers cradle to gate or cradle to grave.
- Early-stage assessments often use cradle-to-gate to guide procurement.
Step 2: Data Collection
The more accurate the data, the more useful the results. This typically involves:
- Transitioning from a detailed Bill of Parts to a consolidated Bill of Materials enables accurate data collection on material quantities and types, streamlining the process of sourcing carbon data for embodied carbon assessments.
- Gather EPDs (Environmental Product Declarations) from suppliers.
- Where unavailable, use international LCA databases.
- Supplier engagement: Working directly with manufacturers and contractors to obtain product-specific information rather than relying on generic averages.
Step 3: Calculation
Using collected data, the project team calculates the embodied carbon of materials and components. This is usually done with the help of life cycle assessment software integrated with BIM models for real-time design analysis.
- Calculations follow established standards like EN 15804+A2 (for product-level data) and ISO 14040/44 (for LCA methodology).
- Results are typically expressed as kg CO₂e per functional unit, enabling comparison between materials, suppliers, or entire design options.
Step 4: Benchmarking
One of the most impactful aspects of an embodied carbon assessment is the ability to test different design pathways:
- Compare traditional concrete with low-carbon mixes.
- Evaluate the benefits of switching from aluminium to recycled alternatives.
- Assess how modular design or reduced structural mass can lower embodied emissions.
Results are then benchmarked against recognised industry targets such as the RIBA 2030 Climate Challenge to evaluate whether the project aligns with best practice.
Step 5: Reporting
The findings of an ECA should be presented in a way that is clear, transparent, and aligned with stakeholder needs. This often involves:
- Communicate results clearly to stakeholders.
- Integrate into sustainability reports and tender submissions.
- Post-construction, compare predicted emissions with actual outcomes to drive learning and accountability
Learn More: Calculating Embodied Carbon in Construction
The Bottom Line
Transitioning to sustainable construction requires addressing both operational and embodied carbon in construction materials. Understanding embodied carbon in construction materials during the planning stage can guide design, procurement and reporting to ensure low-carbon alternatives are prioritised.