What is Embodied Carbon?

Embodied carbon refers to the greenhouse gas emissions associated with building materials and products (raw material supply, transport, manufacturing, etc.). Embodied carbon in the building sector is estimated to be responsible for over 20% of global greenhouse gas emissions.

Image source: Carbon Leadership Forum (CLF)

Reading:

• Carbon Leadership Forum (CLF): https://carbonleadershipforum.org/the-carbon-challenge/
• Institute for Market Transformation (IMT): https://www.imt.org/news/should-i-stay-or-should-i-go-the-embodied-carbon-of-new-and-existing-buildings/
• Rocky Mountain Institute (RMI): https://rmi.org/our-work/buildings/embodied-carbon-initiative/
• BuildingGreen: https://www.buildinggreen.com/feature/urgency-embodied-carbon-and-what-you-can-do-about-it
• Canadian Architect: https://www.canadianarchitect.com/embodied-carbon-the-blindspot-of-the-buildings-industry/
• Greentech Media: https://www.greentechmedia.com/articles/read/climate-pressure-mounts-within-building-industry

Videos:

• HDR Carbon Balance (11 min): https://www.hdrinc.com/insights/carbon-balanced-buildings
• Endeavour Centre (6 min): https://www.youtube.com/watch?v=h1piVin01vQ&list=PLBns4lYIhl5LQ0dmnslqxLuaalX5xpbqi
• Bill Gates (1 min): https://www.youtube.com/watch?app=desktop&v=0__6kx-vTO4

Policy Maps: 

• C40 Clean Construction Policy Explorer
  https://www.c40knowledgehub.org/s/article/Clean-Construction-Policy-Explorer?language=en_US
• Carbon Leadership Forum (CLF) Policy Toolkit https://carbonleadershipforum.org/clf-policy-toolkit/#map

As buildings get more and more energy-efficient, embodied carbon becomes a larger and larger share of the emissions that the building sector is responsible for,  

Image source: Institute for Market Transformation (IMT)

How Does Reuse Reduce Embodied Carbon?

We can drastically cut down on embodied carbon emissions by reusing building materials, because reusing materials reduces the need for some of the most emissions-intensive portions of the life cycle of materials (raw material supply, transport, manufacturing).

According to the consulting company Atelier 10, "Starting with the remaining carbon budget, factoring in the rate at which buildings are currently spending carbon, and the expected rate of construction over the coming decades, we can extrapolate that buildings need to hit a carbon intensity value of just under 200 kgCO2e/m2 each for us to stay under the 1.5 degree mark (and ideally, much below that). Few projects built today are even close to 200 kgCO2e/m2. Hitting this target requires rethinking industry norms, incorporating cutting edge low-carbon products, and committing to building reuse."

The City of Portland was the first city in the US to adopt a deconstruction ordinance. In 2019, a study conducted to estimate the carbon reductions attributed to the ordinance concluded that, "City of Portland data shows that since the ordinance, about 100 single-family homes per year are being deconstructed instead of demolished. With a net carbon reduction per home of 7.6 metric tons of CO2eq over demolition, this equates to a roughly 760 metric tons per year of CO2eq benefit. According to the EPA greenhouse gas equivalencies calculator, this is the same as removing 161 cars from the road for one year, or preventing the use of about 85,000 gallons of gasoline."

Link to more info: 

• Deconstruction vs. Demolition: An evaluation of carbon and energy impacts from deconstructed homes in the City of Portland (2019) https://www.oregon.gov/deq/FilterDocs/DeconstructionReport.pdf

• Setting an Embodied Carbon North Star (2023) https://www.atelierten.com/setting-embodied-carbon-north-star/

Additional resources: 

• US Green Building Council (USGBC) and Rocky Mountain Institute (RMI) - https://www.usgbc.org/resources/driving-action-embodied-carbon-buildings
• LMN Architects - https://lmnarchitects.com/lmn-research/10-existing-building-reuse
• Pacific Institute for Climate Solutions, Making Embodied Carbon Mainstream -  https://pics.uvic.ca/sites/default/files/PICS_Embodied_Carbon_Report_May-2021_FIN.pdf
• Circular Economy Indicators Coalition (CEIC) Corporate Circular Target-Setting Guidance 2023 - https://pacecircular.org/sites/default/files/2023-02/FV_CEIC_Target%20activation%20guides_17.02.23.pdf
• Circle Economy - The Circularity Gap Report 2023 - https://uploads-ssl.webflow.com/5e185aa4d27bcf348400ed82/63ecb3ad94e12d3e5599cf54_CGR%202023%20-%20Report.pdf
• UN Resource Efficiency and Climate Change 2020 https://www.resourcepanel.org/sites/default/files/documents/document/media/resource_efficiency_and_climate_change_full_report.pdf
• Ellen MacArthur Foundation - Completing the Picture - How the Circular Economy Tackles Climate Change 2021 Reprint https://emf.thirdlight.com/file/24/cDm30tVcDDexwg2cD1ZEcZjU51g/Completing%20the%20Picture%20-%20How%20the%20circular%20economy%20tackles%20climate%20change.pdf
• Global ABC Report - Building Materials and the Climate: Constructing a New Future - https://www.buildingmaterialsandclimate.com/

Embodied Carbon Calculator Tools

Many online embodied carbon calculator tools are designed specifically to help you figure this out.

• One Click LCA 
  • Affordability: Offers a free trial
  • Useful for: Embodied carbon comparison of individual materials, whole-building life-cycle analysis; LEED Building Life-Cycle Impact Reduction credit
  • Link to more info: https://www.oneclicklca.com/
• EC3
  • Affordability: Free tool
  • Useful for: Embodied carbon comparison of individual materials, LEED Procurement of Low-Carbon Construction Materials credit
  • Link to more info: https://www.buildingtransparency.org/
• Athena Impact Estimator
  • Affordability: Free tool
  • Useful for: Whole-building life-cycle analysis
  • Link to more info: https://calculatelca.com/software/impact-estimator/
• CARE Tool
  • Affordability: Free tool 
  • Useful for: Estimating the operational and embodied carbon emissions associated with reusing and upgrading an existing building or replacing it with new construction.
  • Link to more info: https://caretool.org/
• EPIC
  • Affordability: Free tool
  • Useful for: Evaluating tradeoff between embodied and operational carbon
  • Link to more info: https://epic.ehdd.com/
• US EPA Waste Reduction Model (WARM)
  • Affordability: Free tool
  • Useful for: Calculating high-level baseline and alternative scenario estimates of greenhouse gas emissions reductions, energy savings and economic impacts of different waste management practices source reduction (can be adapted for reuse), recycling, composting, anaerobic digestion, combustion and landfilling.
  • Link to more info: https://www.epa.gov/warm
• California Air Resources Board, Wood Reuse Calculator Tool (search "Reuse")
  • Affordability: Free tool
  • Useful for: "[Evaluating] carbon sequestration from reusing wood products and avoided GHG emissions from manufacturing of new wood products."
  • Link to more info: https://ww2.arb.ca.gov/resources/documents/cci-quantification-benefits-and-reporting-materials
• Several other tools are listed on the Carbon Leadership Forum (CLF) page here: https://carbonleadershipforum.org/tools-for-measuring-embodied-carbon/