Why Embodied Carbon Matters and What Designers Can Do
Understanding embodied carbon is essential for reducing the environmental impact of buildings from the materials we select to the ways we design.
Why Embodied Carbon Is Crucial in Sustainable Building Design
As the world intensifies efforts to mitigate climate change, the construction sector faces growing scrutiny for its substantial carbon footprint. While much emphasis has historically been placed on operational carbon—the emissions from heating, cooling, lighting, and powering buildings—another formidable source of emissions persists largely out of sight: embodied carbon. Understanding and addressing embodied carbon is rapidly becoming fundamental to responsible design practice and environmental stewardship.
What Is Embodied Carbon?
Embodied carbon encompasses the total greenhouse gas emissions arising from the extraction, manufacturing, transportation, installation, maintenance, and disposal of construction materials throughout a building’s entire lifecycle. Unlike operational emissions, which can be targeted by efficiency upgrades or renewable energy retrofits, embodied carbon is “locked in” at the time of construction and cannot be reduced after the building is completed.
- Extraction and processing: Harvesting raw materials, mining, and initial manufacturing emit significant CO₂.
- Material transport: Hauling these materials to manufacturing facilities and building sites creates transport emissions.
- Construction and installation: On-site activities, equipment, and labor roles contribute further emissions.
- Refurbishment and maintenance: Upgrades and regular upkeep add to the carbon footprint over a building’s life.
- Demolition and end-of-life: Deconstruction, waste transport, landfill/incineration, or recycling close the embodied carbon cycle.
Embodied Carbon vs. Operational Carbon
| Embodied Carbon | Operational Carbon |
|---|---|
| All emissions tied to materials and construction processes—upfront and over the building lifecycle | Emissions from the energy used by a building during its use (heating, cooling, lighting, appliances) |
| “Upfront carbon” is locked in during construction; can’t be retrofitted away | Can be reduced post-occupancy with upgrades, renewable energy adoption, and improved efficiency |
| Requires early design/material decisions and supply chain scrutiny | More easily influenced by occupant behavior and technological improvements over time |
| Share of total carbon footprint grows as operational emissions decline | Historically the dominant focus in green building strategies |
Why Embodied Carbon Demands Our Immediate Attention
Buildings and construction account for nearly 40% of global CO₂ emissions, with embodied carbon expected to make up half of all emissions from new construction between now and 2050. This urgency is driven by several key trends:
- Doubling of global building stock by 2060: We are on track to build the equivalent of a New York City every month for the next four decades, amplifying the impact of embodied emissions with each new project.
- Cement production: Cement alone is responsible for roughly 7% of global carbon emissions, making concrete the world’s second most-consumed material after water.
- Frontloaded emissions: Embodied carbon is discharged before a building even opens its doors, consuming a significant share of our remaining carbon budget early on.
- Decreasing operational footprints: With the energy grid transitioning to renewable sources and building operations becoming more efficient, embodied carbon becomes an ever-larger slice of the emissions pie.
Failure to address embodied carbon today locks in emissions for decades, reducing our ability to stay within global temperature rise limits and making “climate positive” buildings impossible if overlooked.
The Science of Embodied Carbon: Lifecycle Phases
The carbon footprint of a building unfolds across multiple lifecycle phases. Each offers opportunities for intervention and reduction.
What others are reading
- Upfront carbon: Emissions produced in the manufacturing of materials, transportation, and construction before occupancy. These contribute immediately to atmospheric greenhouse gases.
- Use phase: Additional emissions may come from maintenance, repairs, and renovations over the building’s lifespan.
- End-of-life phase: Demolition, material sorting, recycling, and disposal processes at the end of a building’s use.
This is why architects and designers are increasingly expected to consider whole-life carbon: the sum of both operational and embodied carbon from cradle (material extraction) to grave (demolition or recycling).
Why Upfront Carbon Is Critical
Unlike operational emissions, which accrue year by year, upfront carbon has an outsize near-term impact. The earlier a ton of CO₂ is emitted, the greater its contribution to atmospheric warming—an effect known as “carbon frontloading.” This is why policy frameworks like the World Green Building Council’s Net Zero Carbon Buildings Commitment call for urgent action to halve embodied carbon by 2030 and eliminate it entirely by 2050.
Major Drivers of Embodied Carbon in Buildings
Certain materials and construction processes are particularly carbon-intensive. Understanding where the greatest impacts lie enables designers to make targeted choices.
- Cement and concrete: The most widely used building materials, with high emissions due to limestone calcination and fossil fuel energy use.
- Steel: Requires high-temperature processing and has significant transportation emissions, especially for structural components and rebar.
- Aluminum: Energy-intensive extraction and refining processes, though often highly recyclable.
- Glass: Melting and forming processes require large amounts of heat and energy.
- Plastics and insulation: Derived from petrochemicals with emissions from extraction and manufacturing.
- Finishes and flooring: Can include adhesives, resins, or composite materials with non-renewable content and chemical emissions.
Naturally renewable or recycled materials (such as responsibly sourced wood, cellulose insulation, or fly ash in concrete substitutes) generally embody less carbon and, in some cases, can sequester more carbon than they emit.
How Designers Can Reduce Embodied Carbon
Addressing embodied carbon requires engagement at every stage of design and construction. Here are key strategies for reducing emissions and supporting decarbonization across the building sector:
1. Focus on Material Efficiency and Low-Carbon Alternatives
- Specify low-carbon concrete: Use supplementary cementitious materials (SCMs) such as fly ash, slag, or natural pozzolans in concrete mixes to reduce cement content.
- Choose sustainably harvested timber: Engineered wood or mass timber products often have lower carbon footprints and can even act as carbon sinks when sourced responsibly.
- Design for recycling and reuse: Favor modular or prefabricated components to facilitate future disassembly and minimize waste at end-of-life.
- Source regional materials: Minimizing transportation distances substantially reduces emissions from shipping and handling.
- Select finishes with environmental declarations: Use Environmental Product Declarations (EPDs) to compare the embodied carbon of available products and choose those with verified lower impacts.
- Eliminate unnecessary finishes and decorations: Reducing the materials palette and finishing layers cuts emissions and costs.
2. Design for Longevity, Flexibility, and Adaptability
- Plan for adaptable spaces: Buildings that can easily be renovated or reprogrammed extend their useful life and defer demolition emissions.
- Use robust and durable materials: Choosing products built to last reduces the frequency of replacement cycles over the building’s lifespan.
- Embrace timeless design: Timeless architectural aesthetics deter major cosmetic renovations, further lowering cumulative carbon costs.
3. Analyze and Optimize Using Lifecycle Assessment (LCA)
- Simulate early, simulate often: Leverage digital tools to perform whole-building LCAs from schematic design onward for optimal carbon reductions.
- Work collaboratively: Engage engineers, builders, and suppliers early in the design phase to uncover alternatives and optimize structural systems for material efficiency.
- Benchmark and improve: Use case studies and industry benchmarks to set and track performance goals in line with best practices.
4. Advocate for Policy and Standardization
- Support embodied carbon disclosure requirements: Encourage adoption of EPDs and carbon reporting in project procurement processes.
- Follow voluntary and emerging standards: Participate in initiatives like Architecture 2030, SE2050, and the Carbon Leadership Forum.
- Push for high-impact codes: Advocate for updating building codes and zoning laws to support low-carbon alternatives and reuse.
Barriers Designers Face—and How to Overcome Them
Despite growing attention, several challenges impede the reduction of embodied carbon on projects:
- Data availability: Many common products lack comprehensive, third-party verified EPDs. Engaging with manufacturers and asking for transparency can help fill information gaps.
- Upfront cost concerns: Low-carbon options are sometimes perceived as costlier. However, direct savings may arise from using fewer materials, and regulatory penalties or incentives are shifting the calculus.
- Performance uncertainties: Newer materials or methods may require additional verification. Collaborate closely with engineers and testing agencies to ensure code compliance.
- Cultural resistance: Traditional preferences or aesthetic sensibilities can constrain progress. Educate clients about the environmental benefits and showcase beautiful, high-performing projects as exemplars.
The Road Ahead: Making Embodied Carbon Core to Design Practice
Reducing embodied carbon needs to be woven into the fabric of project delivery. The urgency of the climate crisis leaves no room for delay:
- Prioritize carbon in project goals: Make whole-life carbon reduction a key metric—on par with cost, performance, or aesthetics.
- Innovate with materials and construction: Experiment and document new methods that combine lower embodied carbon with reliability and beauty.
- Educate teams and clients: Make carbon literacy a core skill across architecture, engineering, contracting, and supply chain teams.
- Champion leadership: Celebrate and publicize projects and firms that drive meaningful reductions, setting positive examples for the wider industry.
Frequently Asked Questions (FAQs)
Q: What are examples of high embodied carbon materials?
A: Materials such as cement, steel, aluminum, and glass tend to have high embodied carbon due to energy-intensive manufacturing processes. By contrast, responsibly sourced timber, cellulose insulation, and products with recycled content generally have lower embodied carbon.
Q: Why is embodied carbon considered more urgent now than operational carbon?
A: As electricity grids become cleaner and buildings become more efficient, operational emissions decline, making embodied carbon a much higher proportion of a building’s overall impact. Moreover, embodied carbon is discharged immediately, frontloading climate impact compared to operational emissions, which accrue over years.
Q: Can embodied carbon be offset after construction?
A: No. Unlike operational carbon, which can be reduced through upgrades, embodied carbon is fixed once materials are in place. While carbon offsets can be purchased, reducing embodied emissions at the source is the most effective approach.
Q: What tools are available for designers to measure embodied carbon?
A: Lifecycle Assessment (LCA) tools, Environmental Product Declarations (EPDs), and whole-building carbon analysis tools help quantify and compare the carbon footprint of different materials and design choices. Many are available as plugins for BIM or CAD platforms.
Q: What role do building regulations play in reducing embodied carbon?
A: Building codes are beginning to require carbon disclosure and set performance targets, and voluntary standards like LEED, BREEAM, and the Living Building Challenge are awarding points for low-embodied carbon strategies. Designers should proactively monitor regulatory shifts and position projects for compliance.
References
- https://www.aia.org/sites/default/files/2024-11/AIA_CLF_EmbodiedCarbonToolkit_Part1.pdf
- https://www.carboncure.com/blog/concrete-corner/what-is-embodied-carbon/
- https://oneclicklca.com/en-us/resources/articles/embodied-carbon-vs-operational-carbon
- https://ukgbc.org/news/what-is-embodied-carbon-in-construction/
- https://rmi.org/embodied-carbon-101/
- https://worldgbc.org/climate-action/embodied-carbon/
- https://www.aia.org/resource-center/aia-clf-embodied-carbon-toolkit-architects
- https://carbonleadershipforum.org/embodied-carbon-101-v2/
- https://www.architecture2030.org/embodied-carbon-actions/
Similar Articles
Read full bio of Sneha Tete
