When we think about the carbon footprint of buildings, energy use like heating, cooling, and lighting usually comes to mind. But there’s another, less visible piece of the puzzle that’s becoming increasingly important: embodied carbon. These are the emissions tied to everything that goes into making a building, from extracting raw materials to manufacturing, transporting, installing, and eventually disposing of them.
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Thanks to advances in energy efficiency and electrification, we’ve made real progress on reducing emissions from building operations. But the carbon “built into” materials like concrete, steel, glass, and wood is harder to tackle—and it’s quickly becoming a bigger share of a building’s total climate impact.
Right now, construction and renovation activities account for around 5 % of global energy use and 10 % of carbon emissions.1,2 That’s a huge number, and it highlights why understanding and reducing embodied carbon is essential if we’re serious about building sustainably.
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What Are the Sources of Embodied Carbon?
Embodied carbon doesn’t come from just one place—it builds up across every stage of a building’s creation and eventual dismantling. It starts with the fossil fuels used to extract raw materials, continues through the energy-intensive processes of manufacturing and transporting those materials, and includes chemical reactions involved in producing things like cement and steel.
But that’s not all. Additional emissions come from:
- Equipment and machinery used on construction sites
- Waste processing at the end of a building’s life (like incineration or landfill degradation)
- Land-use changes, such as deforestation
- Leaks from refrigerants, particularly hydrofluorocarbons (HFCs)
To better understand where these emissions occur, the building life cycle is broken into four main stages:
- Product (A1–A3): Raw material extraction, transport, and manufacturing
- Construction (A4–A5): Delivery to site and installation
- Use (B1–B7): Maintenance, repair, replacement, and operational energy/water use
- End-of-life (C1–C4): Demolition, waste processing, and disposal
There’s also a fifth, optional stage (Beyond Life (D)), which includes the benefits or burdens of reusing or recycling materials.
Most attention tends to focus on the product stage (A1–A3), often called “cradle-to-gate”, because that’s where data is most available. But for a complete picture of embodied carbon, it's important to assess emissions across all stages (except operational energy and water use in B6 and B7).2
How We Measure Embodied Carbon
Tracking embodied carbon starts with a method called Life Cycle Assessment (LCA). It’s a structured way to measure the environmental impact of a product, process, or building from the moment raw materials are extracted all the way to disposal at the end of its life.
In the case of carbon, the focus is on calculating CO2 equivalents (CO2e)—a standardized way to express the global warming potential of all greenhouse gases over a 100-year period. These emissions are measured in kilograms or metric tons.
There are a few ways LCAs can be applied:
- Product-level LCAs focus on individual materials or products
- Material-level LCAs assess groups of materials, like an entire wall assembly
- Whole Building LCAs (WBLCA) evaluate the total embodied carbon of an entire building
WBLCA is typically done during the design phase, often by architects or sustainability consultants. It helps teams make lower-carbon choices, earn green building certifications, or compare against baseline designs. Tools like Tally, Athena, OneClick LCA, and Beacon are commonly used for this purpose.
That said, there’s still a knowledge gap, mainly because there aren’t enough projects doing this at scale. This makes it tough to create consistent benchmarks across the industry.2
At the product and material level, LCAs are usually conducted by manufacturers or LCA professionals to produce Environmental Product Declarations (EPDs). These are standardized, third-party verified reports that follow Product Category Rules (PCRs)—guidelines that ensure consistent LCA methods for specific product types.
Most EPDs focus on the cradle-to-gate stages (A1–A3), because that’s where data is most readily available. EPDs come in varying levels of detail:
- Industry-wide
- Product-specific
- Facility-specific
- Supply-chain-specific
Each level brings more accuracy, but also requires more detailed data.
There are three main methods for conducting LCAs:
- Input-output
- Process-based
- Hybrid
But regardless of the method, data quality and clear system boundaries are key. Without those, even the most sophisticated tools can produce inconsistent results—something the industry is still working to improve.2
Why Tools and Databases Matter
Measuring embodied carbon accurately and making meaningful decisions based on that data depends heavily on the tools and databases we use. These tools vary in how they work, how much they cost, and how much training they require. Many are free, and some are even built into common design software like Building Information Modeling (BIM) and Revit, making it easier to assess carbon impacts during the design process.
Here’s a quick breakdown of the main types of tools used in embodied carbon analysis:
- Design-Integrated WBLCA Tools: These are built directly into modeling platforms, allowing designers to run whole-building LCAs as they work. Some of these tools are starting to include emissions from building energy systems, like electricity and natural gas, but many still need updates in this area.
- Standalone Building Material and WBLCA Tools: These tools can assess emissions at the material, assembly, or full building level. They’re often used to compare different design options based on embodied carbon.
- Embodied Carbon Calculators: These give estimates of embodied carbon for individual products, building systems, or entire structures. They're useful for early-stage design or high-level comparisons.
- Product and Material Selection Tools: These help users compare the carbon impacts of different materials and can also generate EPDs based on LCA data.
A database powers each of these tools, and that’s where things get even more complex. Some tools rely on integrated databases, while others pull from external sources like:
- Manufacturer-supplied data
- Peer-reviewed academic research
- Government publications
- Industry statistics
- Third-party EPDs
The accuracy of the results depends heavily on the quality of the data and whether it reflects local conditions (like regional electricity grids or manufacturing practices). Some databases account for regional differences through Life Cycle Inventory (LCI) data, but others are more generic or geographically limited—especially those focused on Europe.
Ease of use also varies. Some tools are plug-and-play with minimal training, while others require a solid understanding of LCA principles or even support from a professional. Plus, not every tool evaluates the full life cycle, from cradle-to-gate (A1–A3) to cradle-to-grave (A1–C4). That means the scope of each assessment can differ, which affects how results should be interpreted.
In general, tools tend to focus on either product/material comparisons or whole-building assessments—but rarely both with the same level of depth.2
Bringing Embodied Carbon Upfront
Different Types of Tools and Databases
A wide range of tools now exist to support embodied carbon analysis, from plug-ins that work directly within design software to standalone platforms and web-based calculators. They vary in functionality, life cycle coverage, and the databases they rely on—but all aim to make carbon accounting more accessible and actionable.
Design-integrated tools are especially useful during early design stages. For example, the Hawkins Brown Emissions Reduction Tool and Beacon are both free plug-ins for Revit. They use databases like ICE and support analysis for the product stage (A1–A3), making them ideal for quick assessments of material choices. Tally, another Revit-integrated tool, requires an annual license but provides deeper coverage—spanning from raw material extraction through end-of-life (A1–C4)—using the GaBi database. For designers using Rhino or Grasshopper, the Buildings and Habitat Object Model offers a free alternative, integrating EC3 and Quartz data and covering the full A1–C4 range.
Outside of design platforms, standalone tools like OneClick LCA, Athena, and the GREET Building LCA model provide more flexibility. OneClick (licensed) offers full A1–C4 coverage and optional BIM integration, while Athena (free) uses its own database and supports detailed assessments of assemblies and whole buildings. GREET, developed by Argonne National Lab, focuses on life cycle emissions from building materials.
For quick comparisons or early-stage planning, web-based tools are becoming more common. The Embodied Carbon in Construction Calculator (EC3) is a free platform that helps users find and compare EPDs for construction materials, covering A1–A3. BEES, developed by NIST, evaluates both environmental and economic performance of building products through A1–C4. Tools like Building Carbon Neutral and EPIC provide high-level estimates for whole-building impacts, making them helpful for conceptual design decisions.
Behind all of these tools are databases that supply the life cycle inventory data. Ecoinvent (paid) is one of the most widely used, with a strong focus on European data and broad global coverage. NREL’s LCI database (licensed) offers cradle-to-grave data based on US sources, while GaBi (paid) provides both regional and global datasets across multiple industries.
Choosing the right tool depends on several factors—project stage, region, available data, and how detailed the analysis needs to be. But regardless of the platform, one thing is clear: without solid, transparent data, it's hard to make confident low-carbon design decisions.
Recent Developments in Embodied Carbon Assessment
As interest in embodied carbon continues to grow, researchers and designers are developing new ways to make assessments more accurate, more detailed, and more useful during the design process.
One recent study published in the Journal of Building Engineering proposed a practical, three-step strategy for evaluating embodied carbon using LCA. The approach breaks a building down into four main parts—structure, envelope, interior, and exterior—to pinpoint which areas contribute the most to emissions.
What makes this method stand out is its focus on the often-overlooked exterior, along with a strong emphasis on using EPDs to improve data quality. By supporting clearer section-level analysis and more transparent reporting, the framework helps designers make informed decisions earlier in the design process and benchmark their progress more effectively.3
Another study, featured in Building and Environment, explored how Internet of Things (IoT) technology can be combined with BIM to track embodied carbon in real time—specifically for prefabricated buildings.
The researchers designed a layered system with infrastructure, computing, and application components, and tested it on an actual project in Hong Kong. The findings showed that construction materials were by far the largest source of emissions, though transportation and electricity used by equipment also played a significant role. This type of digital monitoring could help project teams spot issues early and adjust in real time to reduce their carbon footprint.4
Together, these developments point to a future where embodied carbon isn’t just calculated after the fact—it’s monitored, compared, and optimized throughout a building’s life cycle, starting at the very first design sketch.
Conclusion
Embodied carbon may be less visible than operational energy use, but it’s just as important, especially as buildings become more efficient during use. Understanding where these emissions come from and how to measure them is key to designing buildings that are truly low-impact across their full life cycle.
With better LCA tools, more accessible databases, and the growing integration of technologies like BIM and IoT, it’s becoming easier to make carbon-smart decisions early in the design process. But there’s still work to do, especially around data quality, standardization, and education, to help more teams confidently assess and reduce embodied carbon on every project.
The path forward isn’t about perfection—it’s about progress. And the more we measure, compare, and share what we learn, the better we can design and build with climate in mind.
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References and Further Reading
- Amarasinghe, I., Liu, T., Stewart, R. A., Mostafa, S. (2025). Paving the way for lowering embodied carbon emissions in the building and construction sector. Clean Technologies and Environmental Policy, 27(4), 1825-1843. DOI: 10.1007/s10098-024-03023-6, https://link.springer.com/article/10.1007/s10098-024-03023-6
- Embodied Carbon Reduction in New Construction [Online] Available at https://www.energy.gov/sites/default/files/2024-02/bto-abc-embodied-carbon-022624.pdf (Accessed on 22 August 2025)
- Santos, A. K., Ferreira, V. M., Dias, A. C. (2025). Promoting decarbonisation in the construction of new buildings: A strategy to calculate the Embodied Carbon Footprint. Journal of Building Engineering, 103, 112037. DOI: 10.1016/j.jobe.2025.112037, https://www.sciencedirect.com/science/article/pii/S2352710225002736
- Xu, J., Zhang, Q., Teng, Y., Pan, W. (2023). Integrating IoT and BIM for tracking and visualising embodied carbon of prefabricated buildings. Building and Environment, 242, 110492. DOI: 10.1016/j.buildenv.2023.110492, https://www.sciencedirect.com/science/article/abs/pii/S036013232300519X
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