Deep dive: Embodied carbon in real estate & construction — what's working, what's not, and what's next

The built environment accounts for approximately 37% of global energy-related carbon dioxide emissions, and while operational energy efficiency has received decades of policy attention, embodied carbon, the emissions locked into construction materials, manufacturing processes, transportation, and on-site assembly, has only recently entered mainstream discourse. Embodied carbon typically represents 50-80% of a new building's whole-life carbon footprint when measured over a 60-year lifespan, a proportion that grows as operational efficiency improves and electricity grids decarbonise. This deep dive examines what is genuinely working to reduce embodied carbon in real estate and construction, where progress has stalled, and what developments will shape the next phase of action.

Why It Matters

The scale of the challenge is staggering. The International Energy Agency estimates that the global building sector will add 230 billion square metres of new floor area by 2060, equivalent to constructing an entire New York City every month for 35 years. Each square metre of new construction embeds 300-800 kg CO2e depending on structural system, material choices, and regional supply chains. Once a building is constructed, its embodied carbon is permanently committed to the atmosphere. Unlike operational emissions, which can be reduced through retrofits and grid decarbonisation over time, embodied carbon is a one-time, irreversible emission event that occurs primarily during the first two years of a building's life.

Regulatory momentum has accelerated sharply. France's RE2020 regulation, which took effect in January 2022, became the first national building code to set mandatory whole-life carbon limits, requiring new residential buildings to stay below 640 kg CO2e per square metre over a 50-year reference study period. The Netherlands introduced the MPG (Milieuprestatie Gebouwen) requirement with a maximum environmental impact score of 0.5 per square metre per year for new residential buildings. Denmark mandated whole-life carbon assessments for buildings over 1,000 square metres starting in 2023, with absolute limits taking effect in 2025 at 12 kg CO2e per square metre per year. The UK introduced mandatory whole-life carbon assessments for major developments through updates to the National Planning Policy Framework, while several US jurisdictions including New York City, Portland, and Marin County have enacted or proposed embodied carbon regulations targeting public procurement and large private developments.

Financial markets have also taken notice. The Carbon Risk Real Estate Monitor (CRREM) now includes embodied carbon in its stranding risk pathways, and major institutional investors including APG, PGGM, and Norges Bank Investment Management have integrated embodied carbon metrics into their real estate portfolio assessments. The Net Zero Carbon Buildings Commitment, facilitated by the World Green Building Council, explicitly requires signatories to address embodied carbon, not merely operational emissions.

Key Concepts

Whole-Life Carbon Assessment (WLCA) quantifies greenhouse gas emissions across all life cycle stages of a building: product stage (A1-A3, covering raw material extraction, transport, and manufacturing), construction stage (A4-A5), use stage (B1-B7, including maintenance, repair, and replacement), and end-of-life stage (C1-C4, covering demolition, transport, waste processing, and disposal). Module D captures potential benefits beyond the system boundary, such as material reuse or energy recovery. The EN 15978 standard provides the European framework for WLCA, while ISO 21930 and ISO 21931 establish international equivalents.

Environmental Product Declarations (EPDs) are independently verified documents that report the environmental performance of construction products based on life cycle assessment (LCA). EPDs conform to EN 15804 (products) or ISO 14025 (general) and provide the material-level data that feeds into building-level WLCAs. The number of construction EPDs available globally has grown from approximately 15,000 in 2020 to over 90,000 in 2025, though coverage remains uneven across product categories and geographies.

Carbon sequestration in bio-based materials refers to the atmospheric CO2 absorbed during the growth of timber, bamboo, hemp, straw, and other plant-based construction materials. When these materials are incorporated into buildings with service lives of 50-100 years, they function as temporary carbon stores. The accounting treatment of biogenic carbon remains contested, with some frameworks crediting sequestration at the point of construction (module A) and others deferring recognition until end-of-life assumptions are validated.

What's Working

Material Substitution at Structural Scale

The most impactful embodied carbon reductions come from structural material choices, which typically account for 60-70% of a building's total embodied carbon. Mass timber construction has emerged as the most commercially mature low-carbon structural alternative to reinforced concrete and steel. Cross-laminated timber (CLT), glue-laminated timber (glulam), and laminated veneer lumber (LVL) deliver structural performance comparable to concrete for buildings up to 18 storeys while reducing embodied carbon by 40-75% compared to conventional reinforced concrete frames.

Mjostaarnet in Brumunddal, Norway, completed in 2019 at 85.4 metres, demonstrated that mass timber can achieve high-rise performance with embodied carbon approximately 50% lower than a functionally equivalent concrete structure. The Sara Cultural Centre in Skeleftea, Sweden, completed in 2021, incorporated 7,500 cubic metres of timber, sequestering approximately 9,000 tonnes of CO2 while avoiding an estimated 4,000 tonnes of emissions that a concrete alternative would have generated. In North America, the University of British Columbia's Brock Commons Tallwood House achieved a 70% reduction in embodied carbon compared to a conventional concrete and steel design, while meeting all structural, fire safety, and acoustic performance requirements.

Low-carbon concrete has also progressed beyond pilot stage. CarbonCure Technologies has deployed its CO2 mineralisation system in over 700 concrete plants globally, injecting captured CO2 into fresh concrete where it permanently mineralises as calcium carbonate. This process reduces cement content by 5-8% while maintaining or improving compressive strength, translating to 5-8% embodied carbon reduction per cubic metre. CEMEX, Holcim, and Heidelberg Materials have all commercialised blended cements using supplementary cementitious materials (SCMs) including ground granulated blast furnace slag (GGBS), fly ash, and calcined clay, achieving 30-50% clinker replacement ratios and proportional carbon reductions.

Digital Tools for Early-Stage Decision Support

Embodied carbon is largely determined during the first 10-20% of the design process, when structural systems, material palettes, and building geometry are established. Digital tools that enable rapid embodied carbon estimation at concept and schematic design stages have demonstrated significant impact on design outcomes. One Click LCA, used on over 100,000 projects globally, provides automated WLCA calculation integrated with BIM workflows, enabling designers to compare structural options and material specifications in real time.

The UK's Structural Engineers Trading Organisation (SETO), in collaboration with the Institution of Structural Engineers (IStructE), published the SCORS (Structural Carbon Rating Scheme) in 2024, providing benchmark data that enables structural engineers to assess whether their designs fall within acceptable carbon ranges. SCORS data from over 1,200 assessed structures shows that the range between a typical and an optimised design using the same structural system is 30-50%, indicating that engineering optimisation alone, without material substitution, can deliver substantial reductions.

The EC3 (Embodied Carbon in Construction Calculator) tool, developed by the Carbon Leadership Forum and Building Transparency, provides free access to a database of over 100,000 EPDs, enabling specification-stage carbon comparisons across product categories. EC3 has been mandated for use in public procurement by the US General Services Administration and several state governments, demonstrating that open-access tools can drive market transformation when paired with procurement policy.

Procurement and Specification Policies

Buy Clean policies, which set maximum embodied carbon thresholds for construction materials purchased with public funds, have emerged as a powerful demand signal. The US Federal Buy Clean Initiative, announced in 2022 and expanded in 2024, covers steel, concrete, asphalt, and flat glass procured for federal construction projects. California's Buy Clean California Act (AB 262) was the first state-level legislation, setting maximum acceptable global warming potential (GWP) limits for structural steel and reinforcing bar.

The impact of these policies extends beyond public procurement. When governments representing significant purchasing power signal that low-carbon materials will receive preference, manufacturers invest in process decarbonisation to remain competitive. US steel producers including Nucor and Steel Dynamics have accelerated electric arc furnace capacity expansion, partly in response to Buy Clean requirements that favour EAF steel (0.4-0.8 tonnes CO2e per tonne) over integrated blast furnace steel (1.8-2.2 tonnes CO2e per tonne).

What's Not Working

Data Gaps and Inconsistent Methodologies

Despite the growth in EPD availability, significant data gaps persist. EPD coverage is concentrated in Europe and North America, with limited availability for materials manufactured in Asia, Africa, and Latin America, precisely the regions where construction volumes are growing most rapidly. Industry-average EPDs, which use sector-wide data rather than facility-specific measurements, account for approximately 60% of available declarations, limiting their usefulness for differentiating between suppliers.

Methodological inconsistencies across EPD programmes create comparability challenges. Different programme operators apply varying system boundaries, allocation rules, and background database selections, meaning that EPDs for functionally identical products can report different GWP values depending on which programme issued the declaration. The European Commission's work on harmonising EN 15804 implementation through supplementary guidance has improved consistency within Europe, but global harmonisation remains incomplete.

Insufficient Attention to Existing Buildings

The overwhelming focus on new construction embodied carbon overlooks the largest source of construction-related emissions: the demolition and replacement cycle. Demolishing an existing building and constructing a new one, even to the highest sustainability standards, typically generates more cumulative emissions than retrofitting the existing structure for continued use. A 2024 study by the Preservation Green Lab found that it takes 10-80 years for the operational carbon savings of a new high-performance building to offset the embodied carbon of demolishing its predecessor and constructing the replacement.

Yet regulatory frameworks and industry attention remain disproportionately focused on new-build embodied carbon. Retrofit projects lack the standardised assessment methodologies, benchmark data, and policy incentives available for new construction. The result is a systematic bias toward demolition and new-build, which maximises embodied carbon emissions even when retrofit alternatives are technically and economically viable.

Cost Premiums and Value Chain Resistance

Low-carbon materials frequently carry cost premiums that create adoption barriers, particularly in cost-sensitive market segments such as affordable housing and speculative commercial development. Mass timber structural systems typically cost 5-15% more than reinforced concrete equivalents in markets without established timber supply chains, though this premium narrows to 0-5% in regions with mature CLT manufacturing capacity such as Scandinavia and the Pacific Northwest. Low-carbon concrete premiums of 10-30% reflect both the cost of SCMs and the limited competition in low-carbon product categories.

Contractor resistance to unfamiliar materials and construction methods compounds cost challenges. Insurance requirements, warranty concerns, and workforce skills gaps create risk premiums that inflate the apparent cost of low-carbon alternatives. These barriers are particularly acute in markets where regulatory requirements are weak and client demand for embodied carbon reduction remains voluntary.

What's Next

Mandatory Whole-Life Carbon Limits

The trajectory toward mandatory whole-life carbon limits in building codes is clear, though the pace varies by jurisdiction. The EU's revised Energy Performance of Buildings Directive (EPBD), agreed in 2024, requires member states to calculate and disclose whole-life carbon for new buildings from 2028 and to establish maximum limits from 2030. The UK government's Future Homes and Buildings Standards are expected to incorporate embodied carbon requirements, building on the mandatory WLCA disclosures already required for major planning applications.

These regulatory developments will shift embodied carbon from a voluntary reporting exercise to a binding constraint on design and procurement decisions. Sustainability leads should prepare by establishing internal carbon budgets, building WLCA competency within project teams, and engaging supply chains on EPD availability and decarbonisation trajectories.

Industrialised Construction and Design for Disassembly

Off-site manufacturing and modular construction methods offer embodied carbon advantages through material optimisation (5-15% material waste reduction compared to on-site construction), controlled manufacturing environments (enabling higher SCM ratios in concrete and optimised timber utilisation), and potential for design for disassembly (DfD) that extends material service life beyond a single building. DfD principles, where connections are reversible and materials are identifiable and separable, enable recovery and reuse that can offset 20-40% of initial embodied carbon over multiple building life cycles.

Carbon Removal and Storage in Materials

Emerging technologies are transforming construction materials from carbon sources to carbon sinks. Biochar incorporation in concrete and asphalt, enhanced weathering of construction aggregates, and CO2-cured concrete products represent pathways to carbon-negative material systems. CarbonBuilt, Solidia Technologies, and Blue Planet Systems are commercialising concrete products that store more CO2 than they emit during manufacturing, though production volumes remain small relative to conventional concrete markets.

Action Checklist

• Mandate whole-life carbon assessments for all new construction and major renovation projects using EN 15978 or equivalent methodology
• Establish project-level embodied carbon budgets based on RIBA, LETI, or CRREM benchmark data appropriate to building type and location
• Require facility-specific EPDs (not industry-average) for structural materials including concrete, steel, and timber
• Evaluate mass timber and hybrid structural systems for projects where building height and programme permit
• Integrate embodied carbon criteria into procurement scoring, weighting carbon performance alongside cost and schedule
• Prioritise retrofit and adaptive reuse over demolition and new-build wherever technically feasible
• Invest in WLCA training for design teams, structural engineers, and procurement professionals
• Engage contractors on low-carbon construction methods, waste reduction, and design for disassembly principles

Sources

• International Energy Agency. (2024). Global Status Report for Buildings and Construction 2024. Paris: IEA Publications.
• World Green Building Council. (2024). Bringing Embodied Carbon Upfront: Coordinated Action for the Building and Construction Sector. London: WorldGBC.
• Carbon Leadership Forum. (2025). EC3 Tool: User Guide and Methodology Documentation. Seattle: University of Washington.
• Institution of Structural Engineers. (2024). SCORS: Structural Carbon Rating Scheme Benchmark Data Report. London: IStructE.
• Preservation Green Lab. (2024). The Greenest Building: Quantifying the Environmental Value of Building Reuse, Updated Analysis. Washington, DC: National Trust for Historic Preservation.
• European Commission. (2024). Revised Energy Performance of Buildings Directive: Whole-Life Carbon Provisions and Implementation Timeline. Brussels: EC.
• CarbonCure Technologies. (2025). Global Impact Report: CO2 Mineralisation in Concrete Production. Halifax, NS: CarbonCure.
• One Click LCA. (2025). Global Benchmarks for Embodied Carbon in Construction: Analysis of 100,000 Projects. Helsinki: One Click LCA Ltd.