The Developer's Guide to Embodied Carbon
Intervention Points for Building Greener
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Early Visioning
Early Visioning Interventions
Project Example
Portland International Airport Main Terminal Expansion
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Portland, Oregon
Define a big-picture vision for embodied carbon reductions and environmental, social, and governance (ESG) goals.
Read more
Determine applicable green building certifications that focus on materials. The certification program can help define the project-level embodied carbon target.
Measurement and Accounting
Include requirements for tracking and reducing embodied carbon in requests for proposals (RFPs) and contract language for project partners.
Commit to conducting a whole building life cycle assessment (WBLCA) to assess the embodied carbon impact of the project.
Establish internal systems for accountability. Identify embodied carbon champions for each relevant discipline on the project team.
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Pre-Design
Construction Documents
Schematic Design
Design Development
Pre-Design Interventions
Project Example
80 M Street SE
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Washington, DC
Define project-level embodied carbon targets and communicate them in the owner’s project requirements.
Read more
Consider low-carbon structural systems and assemblies (e.g., mass timber, passive house, reused steel, or low-carbon concrete).
Measurement and Accounting
Optimize design: Use less, reuse more, and design for disassembly.
Continue revisiting and refining the building LCA benchmark as needed.
Engage the general contractor as early as possible. Once on board, require the contractor to connect with suppliers about embodied carbon reporting.
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Pre-Design
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Schematic Design
Design Development
Schematic Design Interventions
Project Example
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The Gilbert
Identify the highest-impact portions of the project and immediately engage project team members with design influence over these “hotspots.”
London, England
Read more
Continue optimizing design to use less, reuse more, and design for disassembly.
Measurement and Accounting
Conduct a preliminary embodied carbon assessment using schematic design details.
Ensure a deconstruction assessment is included in the budget and project requirements (see Occupancy).
Read more
See EPA Deconstruction Rapid Assessment Tool
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Schematic Design
Design Development
Design Development Interventions
Project Example
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Pacific Center
Analyze material durability and performance, including aesthetic longevity, to minimize replacement cycles.
San Diego, California
Read more
Work with the engineering team to reduce embodied carbon in MEP systems.
Measurement and Accounting
Create low-carbon specifications that require Environmental Product Declarations for all components considered and tracked for embodied carbon reduction. Start with structural materials, such as concrete, steel, and wood at a minimum.
Use embodied carbon assessment results (alongside cost) to inform the selection of systems and materials.
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Pre-Design
Construction Documents
Schematic Design
Design Development
Construction Documents Interventions
Project Example
Kilroy Oyster Point
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South San Francisco, California
Set emissions targets for products and materials.
Read more
Refine and finalize low-carbon specifications.
Measurement and Accounting
Refine the project’s embodied carbon estimate based on the building’s design and material selection.
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Bidding/Pricing (Procurement)
Construction Administration
Bidding/Pricing (Procurement) Interventions
Project Example
Metropolitan Park (Amazon HQ2)
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Arlington, Virginia
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Create low-carbon bid documents.
Where possible, use embodied carbon data alongside cost data to inform selection of bidders.
Align team members around goals for low-carbon concrete.
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Bidding/Pricing (Procurement)
Construction Administration
Construction Administration
Construction Administration Interventions
Project Example
Skanska Zero Emissions Construction Equipment Pilot
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below for more detail
Los Angeles, California and Stockholm, Sweden
Track and minimize transportation carbon emissions.
Read more
Track and minimize construction site carbon emissions.
Track and minimize construction waste.
Measurement and Accounting
Update the embodied carbon assessment for the as-built project to report actual embodied carbon.
Track and minimize product substitutions.
Ensure preceding steps are noted in pricing.
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Occupancy
Occupancy Interventions
Project Example
Salesforce Benchmarking Study for Furniture and MEP Systems
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below for more detail
Multiple Locations
Provide detailed information about low-carbon products in the building’s operations and maintenance manual.
Read more
Encourage longer replacement cycles of materials.
Work with facilities and maintenance teams to monitor and reduce refrigerant leakage.
Encourage tenants to seek out low-carbon fit-out materials and consider embodied carbon implications of renovations.
Consider green leases and longer tenant leases to reduce turnover.
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Circularity & Material Reuse
Circularity & Material Reuse Interventions
Project Example
Hang Lung Properties Gypsum Board Recycling Programs
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below for more detail
Consider the existing portfolio as a material bank. If you are decommissioning or deconstructing spaces, assess whether materials may be used in other new builds or as replacements in current buildings.
Shanghai and Hangzhou, China
Read more
Promote a circular economy; opt for deconstruction to preserve materials for reuse, including both structural/envelope materials and interior materials.
Gather lessons learned at the end of each project and use them to regularly update corporate policies and design, procurement, and construction standards.
Define project-level embodied carbon targets and communicate them in the owner’s project requirements.
There are two primary approaches to setting project level targets (both require WBLCAs):
- A carbon intensity limit, which sets a maximum carbon footprint per area value for the building
- A percent reduction goals from a baseline value—either for the entire project or on a per-area basis (i.e.. 10 percent reduction from baseline)
NOTE: Baselines values are not widely available in North America.
Resources:
Embodied Carbon Toolkit for Building Owners (Carbon Leadership Forum)
Embodied Carbon Benchmark Study (Carbon Leadership Forum)
Science Based Targets Initiative
Where possible, use embodied carbon data alongside cost data to inform selection of bidders.
Create a standard bid leveling tracker that includes embodied carbon data including fields for if bidder provided EPD, if bidder commits to providing EPD by end of construction, or if bidder would charge the project for the EPD cost.
How to Get an EPD (Building Transparency)
Consider the existing portfolio as a material bank.
If you are decommissioning or deconstructing spaces, assess whether materials may be used in other new builds or as replacements in current buildings. There are many services and organizations that support material reuse, such as the following:
Build Reuse: A national community of organizations dedicated to building material reuse
Rheaply: A software service that supports inventory management and material reuse
Doors Unhinged: A company specializing in reclaimed doors and other building products
Davies Office: A company specializing in furniture remanufacturing
Promote a circular economy; opt for deconstruction to preserve materials for reuse, including both structural/envelope materials and interior materials.
- If the existing building cannot be reused, conduct a deconstruction survey to identify all building materials that can be salvaged for reuse on new project, reused on a different project, or sent to a manufacturer take-back program.
- Look for opportunities to reuse or salvage materials in future projects.
- Take advantage of manufacturer materials take-back programs if demolishing a building.
Refine and finalize low-carbon specifications.
Some materials are prescriptively specified (e.g., gypsum wallboard) while others are specified in a performance-based manner (e.g., concrete). Final concrete mix selection is made at construction.
The Case for Performance Based Concrete Specs (CarbonCure)
Through consultation with the project team, commit to the most feasible strategies that result in lowest embodied carbon.
Ensure selected reduction strategies are reflected in the construction drawings and project manual.
Create low-carbon bid documents.
Include the overall project embodied carbon reduction target alongside material-specific limits.
Create standard embodied carbon bid language for included material categories to inform suppliers of request for or requirement of EPDs.
See model bid document language (Building Transparency).
Require contractors and subcontractors to limit equipment idling time, use Tier IV equipment, and track fuel consumption of construction machinery.
Ask for estimated transportation carbon emissions.
Ask for estimated construction site carbon emissions.
Track and minimize construction waste.
Track construction waste, including the diversion rate.Source separate waste for major material streams to enable a higher recycling rate. When creating a demolition plan, look for opportunities for deconstruction and salvage materials where possible. Require high percentage construction waste diversion from landfill in project requirements and contracts for general contractors. Include desire or requirement for a certain percentage of material salvage for reuse and/or commit to manufacturer materials take-back programs if demolishing an existing building.
Engage the general contractor as early as possible. Once on board, require the contractor to connect with suppliers about embodied carbon reporting.
Create a list of suppliers and subcontractors you typically specify, procure, or purchase from.
Use an online tool—such as the Embodied Carbon in Construction Calculator (EC3)
—to determine if they have product-specific EPDs.
Set up meetings with suppliers who do not have product-specific EPDs to educate them on embodied carbon.
Send an official EPD request letter to suppliers to formalize ask and build a business case. See EPD Request Letter by Building Transparency.
How to Get an EPD (Building Transparency)
Track and minimize construction waste.
Track construction waste, including the diversion rate.Source separate waste for major material streams to enable a higher recycling rate. When creating a demolition plan, look for opportunities for deconstruction and salvage materials where possible. Require high percentage construction waste diversion from landfill in project requirements and contracts for general contractors. Include desire or requirement for a certain percentage of material salvage for reuse and/or commit to manufacturer materials take-back programs if demolishing an existing building.
Optimize design: Use less, reuse more, and design for disassembly.
Use Less
Design for Disassembly
As an industry, using less material overall is critical to carbon reduction efforts.
Designing for disassembly considers how a project's materials will be salvaged and reused after the building has reached the end of its useful life.
- Right-sizing: Evaluate programmatic requirements to optimize space use. Consider minimizing the addition of new floor area to reduce new material production.
Buildings that Last: Design for Adaptability, Deconstruction, and Reuse (AIA)
- Dematerializing: Maximize material efficiency and minimize excess. This can be achieved through the optimization of the structural systems or by selecting structural materials that can remain exposed, reducing the need for finishing materials.
Design for Disassembly in the Built Environment: A Guide to Closed-Loop Design and Building (King County)
- Reduce or eliminate below-grade parking wherever possible, particularly in certain soil conditions.
Additional Resources
AIA-CLF Toolkit for Architects - Part III: Strategies for Reducing Embodied Carbon
Reuse More
- Include material reuse when deciding on major structure and envelope systems.
For sites and infrastructure, see Climate Positive Design Toolkit (Climate Positive Design)
- If planning to procure salvaged materials, determine what is available locally.
Optimize design: Use less, reuse more, and design for disassembly.
Use Less
Design for Disassembly
As an industry, using less material overall is critical to carbon reduction efforts.
Designing for disassembly considers how a project's materials will be salvaged and reused after the building has reached the end of its useful life.
- Right-sizing: Evaluate programmatic requirements to optimize space use. Consider minimizing the addition of new floor area to reduce new material production.
Buildings that Last: Design for Adaptability, Deconstruction, and Reuse (AIA)
- Dematerializing: Maximize material efficiency and minimize excess. This can be achieved through the optimization of the structural systems or by selecting structural materials that can remain exposed, reducing the need for finishing materials.
Design for Disassembly in the Built Environment: A Guide to Closed-Loop Design and Building (King County)
- Reduce or eliminate below-grade parking wherever possible, particularly in certain soil conditions.
Additional Resources
AIA-CLF Toolkit for Architects - Part III: Strategies for Reducing Embodied Carbon
Reuse More
- Include material reuse when deciding on major structure and envelope systems.
For sites and infrastructure, see Climate Positive Design Toolkit (Climate Positive Design)
- If planning to procure salvaged materials, determine what is available locally.
Engage the general contractor as early as possible. Once on board, require the contractor to connect with suppliers about embodied carbon reporting.
Create a list of suppliers and subcontractors you typically specify, procure, or purchase from.
Use an online tool—such as the Embodied Carbon in Construction Calculator (EC3)
—to determine if they have product-specific
EPDs.
Set up meetings with suppliers who do not have product-specific EPDs to educate them on embodied carbon.
Send an official EPD request letter to suppliers to formalize ask and build a business case. See EPD Request Letter by Building Transparency.
How to Get an EPD (Building Transparency)
Determine applicable green building certifications that focus on materials. The certification program can help define the project-level embodied carbon target.
Popular sustainability certification programs:
Leadership in Energy and Environmental Design (LEED)
International Living Future Institute (ILFI) Zero Carbon
International Living Future Institute (ILFI) Living Building Challenge
Resource:
Comparing Building Standards from Around the World v2.0 (RESET)
Provide detailed information about low-carbon products in the building’s operations and maintenance manual.
Include information about circular products, products designed for disassembly, and any products that are eligible for manufacturer take-back programs.
Consider providing a full set of deconstruction documents.
Track and minimize product substitutions.
Review submittals and change orders to ensure compliance with low-carbon specification criteria.
Work with the engineering team to reduce embodied carbon in MEP systems.
NOTE: Many WBLCAs omit emissions from MEP systems. More research and data are needed on MEP systems and their contribution to a new building’s embodied carbon.
If possible, avoid refrigerants. If refrigerants must be used, request low global warming potential (GWP) refrigerants.
Resources:
Life Cycle Assessment of Mechanical, Electrical, and Plumbing in Commercial Office Buildings (CLF)
MEP2040
Consider the existing portfolio as a material bank.
If you are decommissioning or deconstructing spaces, assess whether materials may be used in other new builds or as replacements in current buildings. There are many services and organizations that support material reuse, such as the following:
Build Reuse: A national community of organizations dedicated to building material reuse
Rheaply: A software service that supports inventory management and material reuse
Doors Unhinged: A company specializing in reclaimed doors and other building products
Davies Office: A company specializing in furniture remanufacturing
Track and minimize product substitutions.
Review submittals and change orders to ensure compliance with low-carbon specification criteria.
Optimize design: Use less, reuse more, and design for disassembly.
Design for Disassembly
Use Less
As an industry, using less material overall is critical to carbon reduction efforts.
Designing for disassembly considers how a project's materials will be salvaged and reused after the building has reached the end of its useful life.
- Right-sizing: Evaluate programmatic requirements to optimize space use. Consider minimizing the addition of new floor area to reduce new material production.
Buildings that Last: Design for Adaptability, Deconstruction, and Reuse (AIA)
- Dematerializing: Maximize material efficiency and minimize excess. This can be achieved through the optimization of the structural systems or by selecting structural materials that can remain exposed, reducing the need for finishing materials.
Design for Disassembly in the Built Environment: A Guide to Closed-Loop Design and Building (King County)
- Reduce or eliminate below-grade parking wherever possible, particularly in certain soil conditions.
Additional Resources
AIA-CLF Toolkit for Architects - Part III: Strategies for Reducing Embodied Carbon (AIA, CLF)
Reuse More
- Include material reuse when deciding on major structure and envelope systems.
For sites and infrastructure, see Climate Positive Design Toolkit (Climate Positive Design)
- If planning to procure salvaged materials, determine what is available locally.
See the Climate Positive Design Toolkit for sites and infrastructure.
Where possible, use embodied carbon data alongside cost data to inform selection of bidders.
Create a standard bid leveling tracker that includes embodied carbon data including fields for if bidder provided EPD, if bidder commits to providing EPD by end of construction, or if bidder would charge the project for the EPD cost.
How to Get an EPD (Building Transparency)
Define a big-picture vision for embodied carbon reductions and environmental, social, and governance (ESG) goals.
Determine how the project fits into your company’s overall embodied carbon reduction goals and ESG strategies.
Consider if reusing or renovating an existing building might fulfill project requirements. (Ask: do we need to build?)
Determine applicable green building certifications that focus on materials. The certification program can help define the project-level embodied carbon target.
Popular sustainability certification programs:
Leadership in Energy and Environmental Design (LEED)
International Living Future Institute (ILFI) Zero Carbon
International Living Future Institute (ILFI) Living Building Challenge
Resource:
Comparing Building Standards from Around the World v2.0 (RESET)
Track and minimize transportation carbon emissions.
Create standard supplier bid language and reporting forms.
Track material manufacturing location, distance traveled to site, mode of transportation, and fuel type.
Create a summary sheet for reporting and tracking of transport emissions throughout the project’s completion.
Set emissions targets for products and materials.
There are two main approaches for setting emission targets for products and materials:
- Set a maximum carbon footprint per unit of material, such as a cubic yard of concrete; or
- Adopt percent reduction goals from a baseline value total or per functional unit of material.
Where possible, use industry average EPDs, CLF baselines, or an EC3 average to create a baseline and identify an achievable target for each material category based on available collections of EPDs.
Resources:
Embodied Carbon Toolkit for Building Owners (CLF)
Procurement Policies to Reduce Embodied Carbon (CLF)
EC3 - Embodied Carbon in Construction Calculator (Building Transparency)
Consider low-carbon structural systems and assemblies (e.g., mass timber, passive house, recycled or reused steel, or low-carbon concrete).
Mass timber can be an environmentally friendly choice when compared to traditional construction materials. Trees sequester carbon while they are growing and will continue to store carbon after they are harvested and turned into mass timber. The manufacturing process is also significantly less energy- and water-intensive compared to concrete and steel production. To learn more about mass timber, visit: WoodWorks.
Passive house is a building design standard that promotes ultra-airtight building envelopes to maintain interior temperatures and save energy. Passive house helps reduce demand on heating and cooling systems, helping avoid refrigerants and materials for MEP systems, which generally have high global warming potential. To learn more about passive house, visit: Passive House.
Recycled steel (also known as secondary steel) is a preferred choice for reducing embodied carbon. The production of recycled steel in an electric arc furnace (EAF) requires less energy compared to the manufacturing process for primary steel. Currently, the most effective way to reduce embodied carbon from steel is to use less material overall. To learn more about embodied carbon reductions in steel, see: Arup Embodied Carbon of Steel (2020)
Low-carbon concrete encompasses a broad range of innovations that aim to reduce the global warming potential of concrete mixes. These approaches might include material- or process-based solutions. Currently, the most effective way to reduce embodied carbon from concrete is to use less material overall. To learn more about innovations in low-carbon concrete, visit: RMI The 3Cs of Innovation in Low Carbon Concrete (2023)
Work with the engineering team to reduce embodied carbon in MEP systems.
NOTE: Many WBLCAs omit emissions from mechanical, engineering, and plumbing (MEP) systems. More research and data are needed on MEP systems and their contribution to a new building’s embodied carbon.
If possible, avoid refrigerants. If refrigerants must be used, request low global warming potential (GWP) refrigerants.
Resources:
Life Cycle Assessment of Mechanical, Electrical, and Plumbing in Commercial Office Buildings (CLF)
MEP 2040
Work with facilities and maintenance teams to monitor and reduce refrigerant leakage.
See Refrigerant Management (Project Drawdown)
Work with facilities and maintenance teams to monitor and reduce refrigerant leakage.
- See Refrigerant Management (Project Drawdown).
Include requirements for tracking and reducing embodied carbon in requests for proposals (RFPs) and contract language for project partners.
Include requirements for managing embodied carbon, including completing embodied carbon assessments, collecting Environmental Product Declarations (EPDs), identifying reduction opportunities, and implementing strategies.
How to Get an EPD (Building Transparency)
Include requirements for tracking and reducing embodied carbon in requests for proposals (RFPs) and contract language for project partners.
Include requirements for managing embodied carbon, including completing embodied carbon assessments, collecting Environmental Product Declarations (EPDs), identifying reduction opportunities, and implementing strategies.
How to Get an EPD (Building Transparency)
Metropolitan Park (Amazon HQ2)
Quick Facts
Arlington, Virginia
Developers: Amazon and JBG Smith
Designer: ZGF
Other partners: Thornton Tomasetti (structural), GHT (MEP), Clark Construction (general contractor), Seneca Group (owner’s representative and development manager) Size: 2.1 million square feet Project type: New construction
Status: Completed
Amazon’s second headquarters in Arlington, Virginia, exemplifies the company’s commitment to sustainability through reductions in both embodied and operational carbon.
Partnerships between the design team, general contractor, and suppliers were integral to the project’s success. Amazon specified its embodied carbon reduction goals in its contracts with project partners, signaling its commitment to low-carbon construction and setting the stage for embodied carbon reductions during the procurement phase. To meet their goals, the project team adopted performance-based specifications for the concrete and empowered producers to use a variety of methods for reducing carbon in their designs. Compared to traditional prescriptive specifications that require certain ratios of cement for concrete mixes, performance-based specifications give suppliers the freedom to create mixes based on performance criteria for the application. At Met Park, this approach allowed suppliers to leverage different technologies and meet both the project’s structural requirements and embodied carbon reduction goals.
A collaborative approach to procurement and meticulous attention to life cycle emissions helped the 2.1-million-square-foot project achieve a 20 percent reduction in the embodied carbon of its concrete structures compared to the industry baseline. This saved over 14,700 metric tons of carbon, or the equivalent of taking more than 3,200 cars off the road for an entire year. The project also integrated concrete made with CarbonCure, a technology that injects recycled carbon dioxide into concrete, increasing the strength of the mix while reducing embodied carbon. The CarbonCure technology has since been used at over 40 other Amazon global construction sites along with many other low-carbon concrete solutions within the company’s global portfolio.
Met Park also integrated other low-carbon building materials such as mass timber to further drive down embodied carbon. A mass timber ceiling in the meeting center features cross-laminated timber and glue-laminated timber beams, providing not just aesthetic value but also carbon reduction benefits, as wood absorbs carbon as it grows and continues to store that carbon throughout its material life cycle in the building.
Together, these strategies helped Amazon’s HQ2 achieve significant carbon reductions as well as LEED v4 Platinum certification, making it the largest newly constructed building and LEED V4 BD+C project to achieve this recognition.
Identify the highest-impact portions of the project and immediately engage project team members with design influence over these “hotspots.”
While every project is different, studies have consistently shown structure, enclosure, and MEP systems are the leading elements for new buildings, and materials with the highest contributions are typically concrete and steel.
Encourage early consideration with the structural engineer specifically around low carbon goals, optimizing structural material and bay sizes, and the low carbon concrete process.
Seek out engineering firms that have signed on to low-carbon commitments, such as:
SE2050
MEP 2040
Refine and finalize low-carbon specifications.
Some materials are prescriptively specified (e.g., gypsum wallboard) while others are specified in a performance-based manner (e.g., concrete). Final concrete mix selection is made at construction.
The Case for Performance Based Concrete Specs (CarbonCure)
Through consultation with the project team, commit to the most feasible strategies that result in lowest embodied carbon.
Ensure selected reduction strategies are reflected in the construction drawings and project manual.
Track and minimize construction site carbon emissions.
Track construction equipment fuel consumption per activity and material scope.
AGC Playbook on Decarbonization and Carbon Reporting in the Construction Industry
Identify and implement strategies to reduce equipment fuel emissions, such as using electrified equipment.
Create a summary sheet for reporting and tracking of transport emissions throughout the project’s completion.
Determine applicable green building certifications that focus on materials. The certification program can help define the project-level embodied carbon target.
Popular sustainability certification programs:
Leadership in Energy and Environmental Design (LEED)
International Living Future Institute (ILFI) Zero Carbon
International Living Future Institute (ILFI) Living Building Challenge
Resource:
Comparing Building Standards from Around the World v2.0 (RESET)
Encourage tenants to seek out low-carbon fit-out materials and consider embodied carbon implications of renovations.
Consider setting GWP limits for material and equipment replacements, when EPDs are available.
Avoid “white-boxing” spaces between tenants; encourage new tenants to retain existing fit-outs when possible.
Fitting Out Spaces for Net Zero (ULI)
Low Embodied Carbon Tenant Fit-Out Guide (Hudson Pacific Properties)
Track and minimize construction waste.
Track construction waste, including the diversion rate.Source separate waste for major material streams to enable a higher recycling rate. When creating a demolition plan, look for opportunities for deconstruction and salvage materials where possible. Require high percentage construction waste diversion from landfill in project requirements and contracts for general contractors. Include desire or requirement for a certain percentage of material salvage for reuse and/or commit to manufacturer materials take-back programs if demolishing an existing building.
Consider green leases and longer tenant leases to reduce turnover.
- See Taking Green Leases to Net Zero (ULI).
Provide detailed information about low-carbon products in the building’s operations and maintenance manual.
Include information about circular products, products designed for disassembly, and any products that are eligible for manufacturer take-back programs.
Consider providing a full set of deconstruction documents.
Optimize design: Use less, reuse more, and design for disassembly.
Use Less
Design for Disassembly
As an industry, using less material overall is critical to carbon reduction efforts.
Designing for disassembly considers how a project's materials will be salvaged and reused after the building has reached the end of its useful life.
- Right-sizing: Evaluate programmatic requirements to optimize space use. Consider minimizing the addition of new floor area to reduce new material production.
Buildings that Last: Design for Adaptability, Deconstruction, and Reuse (AIA)
- Dematerializing: Maximize material efficiency and minimize excess. This can be achieved through the optimization of the structural systems or by selecting structural materials that can remain exposed, reducing the need for finishing materials.
Design for Disassembly in the Built Environment: A Guide to Closed-Loop Design and Building (King County)
- Reduce or eliminate below-grade parking wherever possible, particularly in certain soil conditions.
Additional Resources
AIA-CLF Toolkit for Architects - Part III: Strategies for Reducing Embodied Carbon
Reuse More
- Include material reuse when deciding on major structure and envelope systems.
For sites and infrastructure, see Climate Positive Design Toolkit (Climate Positive Design)
- If planning to procure salvaged materials, determine what is available locally.
Create low-carbon bid documents.
Include the overall project embodied carbon reduction target alongside material-specific limits.
Create standard embodied carbon bid language for included material categories to inform suppliers of request for or requirement of EPDs.
See model bid document language (Building Transparency).
Require contractors and subcontractors to limit equipment idling time, use Tier IV equipment, and track fuel consumption of construction machinery.
Ask for estimated transportation carbon emissions.
Ask for estimated construction site carbon emissions.
Consider green leases and longer tenant leases to reduce turnover.
See Taking Green Leases to Net Zero (ULI)
Embodied Carbon Measurement and Accounting
Conduct a preliminary
embodied carbon assessment
using schematic design details.
Resources:
AIA-CLF Embodied Carbon Toolkit for Architects Part II: Measuring Embodied Carbon
Tools for Measuring Embodied Carbon (CLF)
Create low-carbon specifications that require EPDs for all components considered and tracked for embodied carbon reduction. Start with structural materials, such as concrete, steel, and wood at a minimum.
Include intentions for salvaged materials, circular materials, and materials with manufacturer take-back programs.
Reach out to suppliers to check on low-carbon product availability.
If selected products do not have an EPD, send an official EPD request letter to suppliers to formalize ask and build a business case.
Download an EPD Request Letter (Building Transparency)
How to Get an EPD (Building Transparency)
80 M Street SE
Washington, DC
Quick Facts
At 80 M Street SE, developer Columbia Property Trust added a vertical mass timber extension to an existing seven-story concrete building in the heart of Washington, D.C.’s Navy Yard neighborhood. The three-floor addition delivers 104,000 square feet of trophy-class office space and nearly 4,000 square feet of outdoor amenity space. Overbuilds offer a creative approach for adding square footage while minimizing the environmental impacts from demolishing and constructing a new building. 80 M is the first commercial office building in D.C. to feature a vertical extension constructed of mass timber.
The project exemplifies how smart decision-making in early design phases can result in significant embodied carbon savings. In pre-design, Columbia Property Trust supported an initial study of the mass timber option because of the material’s reduced density (relative to other superstructure materials), aesthetic qualities, lower carbon footprint, reduced schedule of on-site activities, and potential for differentiating 80 M from standard class A office buildings in the neighborhood. When the option proved feasible, the design team established mass timber as the Basis of Design.* This was critical for ensuring that mass timber would be seriously considered as a viable option for the extension.
The cost of mass timber was comparable to the conventional steel option and only carried a slight premium, which was offset by higher per-square-foot lease rates and an overall faster lease-up. In addition, contractor DAVIS solicited multiple bids on mass timber to collect competitive pricing, further enabling the material to be financially viable. Once the selected mass timber contractor was on board, DAVIS managed the process of working through the final construction details to ensure the design could be implemented successfully. In total, the mass timber option resulted in a 40 percent reduction in cradle-to-grave structural embodied carbon compared to a standard structural system of concrete and steel.
Developer: Columbia Property Trust
Designer: Hickok Cole Architects
Other partners: Arup, DAVIS
Size: 104,000 square feet (overbuild only)
Project type: Renovation and expansion
Status: Completed February 2022
* The Basis of Design documents the principles, assumptions, rationale, criteria, and considerations used for calculations and decisions during design.
Optimize design: Use less, reuse more, and design for disassembly.
Design for Disassembly
Use Less
As an industry, using less material overall is critical to carbon reduction efforts.
Designing for disassembly considers how a project's materials will be salvaged and reused after the building has reached the end of its useful life.
- Right-sizing: Evaluate programmatic requirements to optimize space use. Consider minimizing the addition of new floor area to reduce new material production.
Buildings that Last: Design for Adaptability, Deconstruction, and Reuse (AIA)
- Dematerializing: Maximize material efficiency and minimize excess. This can be achieved through the optimization of the structural systems or by selecting structural materials that can remain exposed, reducing the need for finishing materials.
Design for Disassembly in the Built Environment: A Guide to Closed-Loop Design and Building (King County)
- Reduce or eliminate below-grade parking wherever possible, particularly in certain soil conditions.
Additional Resources
AIA-CLF Toolkit for Architects - Part III: Strategies for Reducing Embodied Carbon (AIA, CLF)
Reuse More
- Include material reuse when deciding on major structure and envelope systems.
For sites and infrastructure, see Climate Positive Design Toolkit (Climate Positive Design)
- If planning to procure salvaged materials, determine what is available locally.
See the Climate Positive Design Toolkit for sites and infrastructure.
Encourage tenants to seek out low-carbon fit-out materials and consider embodied carbon implications of renovations.
- See ULI Tenant Fit-out Primer.
- See Low Embodied Carbon Tenant Fit-Out Guide (Hudson Pacific Properties).
- Consider setting GWP limits for material and equipment replacements, when EPDs are available.
- Avoid “white-boxing” spaces between tenants; encourage new tenants to retain existing fit-outs when possible.
Where possible, use embodied carbon data alongside cost data to inform selection of bidders.
Create a standard bid leveling tracker that includes embodied carbon data including fields for if bidder provided EPD, if bidder commits to providing EPD by end of construction, or if bidder would charge the project for the EPD cost.
How to Get an EPD (Building Transparency)
Encourage longer replacement cycles of materials.
Assess current standards and practices for determining material replacement during a building’s use phase.
Commit to replacement cycles based on material and product performance (versus a desired change in aesthetic) and include this in building standards.
Analyze material durability and performance, including aesthetic longevity, to minimize replacement cycles.
NOTE: This analysis does not necessarily provide the full picture. If a product is less durable, but is lower in embodied carbon, bio-based, circular, has a take-back program, and/or is low-toxicity, it could be a better choice.
Define a big-picture vision for embodied carbon reductions and environmental, social, and governance (ESG) goals.
Determine how the project fits into your company’s overall embodied carbon reduction goals and ESG strategies.
Consider if reusing or renovating an existing building might fulfill project requirements. (Ask: do we need to build?)
Create low-carbon specifications that require Environmental Product Declarations (EPDs) for all components considered and tracked for embodied carbon reduction. Start with structural materials, such as concrete, steel, and wood at a minimum.
Include intentions for salvaged materials, circular materials, and materials with manufacturer take-back programs.
Reach out to suppliers to check on low-carbon product availability.
If selected products do not have an EPD, send an official EPD request letter to suppliers to formalize ask and build a business case.
Download an EPD Request Letter (Building Transparency)
How to Get an EPD (Building Transparency)
Promote a circular economy; opt for deconstruction to preserve materials for reuse, including both structural/envelope materials and interior materials.
If the existing building cannot be reused, conduct a deconstruction survey to identify all building materials that can be salvaged for reuse on new project, reused on a different project, or sent to a manufacturer take-back program.
Look for opportunities to reuse or salvage materials in future projects.
Take advantage of manufacturer materials take-back programs if demolishing a building.
Define project-level embodied carbon targets and communicate them in the owner’s project requirements.
There are two primary approaches to setting project level targets (both require WBLCAs):
- A carbon intensity limit, which sets a maximum carbon footprint per area value for the building
- A percent reduction goals from a baseline value—either for the entire project or on a per-area basis (i.e.. 10 percent reduction from baseline)
NOTE: Baselines values are not widely available in North America.
Resources:
Embodied Carbon Toolkit for Building Owners (Carbon Leadership Forum)
Embodied Carbon Benchmark Study (Carbon Leadership Forum)
Science Based Targets Initiative
Promote a circular economy; opt for deconstruction to preserve materials for reuse, including both structural/envelope materials and interior materials.
If the existing building cannot be reused, conduct a deconstruction survey to identify all building materials that can be salvaged for reuse on new project, reused on a different project, or sent to a manufacturer take-back program.
Look for opportunities to reuse or salvage materials in future projects.
Take advantage of manufacturer materials take-back programs if demolishing a building.
Create low-carbon bid documents.
Include the overall project embodied carbon reduction target alongside material-specific limits.
Create standard embodied carbon bid language for included material categories to inform suppliers of request for or requirement of EPDs.
Model bid document language (Building Transparency)
Require contractors and subcontractors to limit equipment idling time, use Tier IV equipment, and track fuel consumption of construction machinery.
Ask for estimated transportation carbon emissions.
Ask for estimated construction site carbon emissions.
Analyze material durability and performance, including aesthetic longevity, to minimize replacement cycles.
NOTE: This analysis does not necessarily provide the full picture. If a product is less durable, but is lower in embodied carbon, bio-based, circular, has a take-back program, and/or is low-toxicity, it could be a better choice.
Work with facilities and maintenance teams to monitor and reduce refrigerant leakage.
Refrigerant Management (Project Drawdown)
Identify the highest-impact portions of the project and immediately engage project team members with design influence over these “hotspots.”
While every project is different, studies have consistently shown structure, enclosure, and MEP systems are the leading elements for new buildings, and materials with the highest contributions are typically concrete and steel.
Encourage early consideration with the structural engineer specifically around low carbon goals, optimizing structural material and bay sizes, and the low carbon concrete process.
Seek out engineering firms that have signed on to low-carbon commitments, such as:
SE2050
MEP2040.
Work with the engineering team to reduce embodied carbon in MEP systems.
NOTE: Many WBLCAs omit emissions from MEP systems. More research and data are needed on MEP systems and their contribution to a new building’s embodied carbon.
If possible, avoid refrigerants. If refrigerants must be used, request low global warming potential (GWP) refrigerants.
Resources:
Life Cycle Assessment of Mechanical, Electrical, and Plumbing in Commercial Office Buildings (CLF)
MEP2040
Embodied Carbon Measurement and Accounting
Use
results (alongside cost) to inform the selection of systems and materials.
embodied carbon assessment
Run material and system options through an embodied carbon assessment tool to understand associated emission data for each option. Compare embodied carbon data alongside cost to inform decision making.
Calculate the embodied carbon avoidance potential of identified strategies and investigate any performance, cost, or schedule tradeoffs.
Continue to evaluate high-impact material categories and available emissions reductions.
Factor in transportation emissions. Consider tradeoffs between product-level emissions and transportation emissions.
Resources:
AIA-CLF Embodied Carbon Toolkit for Architects Part II: Measuring Embodied Carbon
Tools for Measuring Embodied Carbon (CLF)
Define a big-picture vision for embodied carbon reductions and environmental, social, and governance (ESG) goals.
Determine how the project fits into your company’s overall embodied carbon reduction goals and ESG strategies.
Consider if reusing or renovating an existing building might fulfill project requirements. (Ask: do we need to build?)
Embodied Carbon Measurement and Accounting
Commit to conducting a whole building life cycle assessment (WBLCA) to assess the embodied carbon impact of the project.
Similar to energy modeling, architects (or their consultants) should perform WBLCAs throughout the design process to actively inform the design of a building.
- Determine which building elements are to be included in the embodied carbon assessment. In addition to structure and enclosure, consider assessing mechanical, electrical, and plumbing (MEP) systems, interiors, and site embodied carbon.
- Identify a baseline building or third-party benchmark to use as a reference point to evaluate the project’s relative embodied carbon performance.
- Building-level life cycle assessment (LCA) benchmarks are not yet widely available in North America, but efforts are underway. Architecture firms that perform WBLCA regularly can create their own firm benchmarks for different project types. See links under "Benchmarking" to the right for guidance.
- Select embodied carbon analysis tools you will use for calculation, measurement, and accounting. There are many different tools available for evaluating buildings and building materials.
Resources:
Benchmarking
Embodied Carbon Benchmark Study (CLF)
Science Based Targets Initiative
Measurement
AIA-CLF Embodied Carbon Toolkit for Architects Part II: Measuring Embodied Carbon
Tools for Measuring Embodied Carbon (CLF)
Tools
EPIC: Early Phase Integrated Carbon Assessment
CARE: Carbon Avoided Retrofit Estimator
Align team members around goals for low-carbon concrete.
Hold a preconstruction meeting with the general contractor, structural engineer, architect, sustainability consultant, and ready-mix supplier to discuss low-carbon concrete expectations, goals, procurement process, and responsibilities.
Set emissions targets for products and materials.
There are two main approaches for setting emission targets for products and materials:
- Set a maximum carbon footprint per unit of material, such as a cubic yard of concrete; or
- Adopt percent reduction goals from a baseline value total or per functional unit of material.
Where possible, use industry average EPDs, CLF baselines, or an EC3 average to create a baseline and identify an achievable target for each material category based on available collections of EPDs.
Resources:
Embodied Carbon Toolkit for Building Owners (CLF)
Procurement Policies to Reduce Embodied Carbon (CLF)
EC3 - Embodied Carbon in Construction Calculator (Building Transparency)
Consider low-carbon structural systems and assemblies (e.g., mass timber, passive house, recycled or reused steel, or low-carbon concrete).
Mass timber can be an environmentally friendly choice when compared to traditional construction materials. Trees sequester carbon while they are growing and will continue to store carbon after they are harvested and turned into mass timber. The manufacturing process is also significantly less energy- and water-intensive compared to concrete and steel production.
WoodWorks
Passive house is a building design standard that promotes ultra-airtight building envelopes to maintain interior temperatures and save energy. Passive house helps reduce demand on heating and cooling systems, helping avoid refrigerants and materials for MEP systems, which generally have high global warming potential.
Passive House
Recycled steel (also known as secondary steel) is a preferred choice for reducing embodied carbon. The production of recycled steel in an electric arc furnace (EAF) requires less energy compared to the manufacturing process for primary steel. Currently, the most effective way to reduce embodied carbon from steel is to use less material overall.
Embodied Carbon of Steel (Arup)
Low-carbon concrete encompasses a broad range of innovations that aim to reduce the global warming potential of concrete mixes. These approaches might include material- or process-based solutions. Currently, the most effective way to reduce embodied carbon from concrete is to use less material overall.
The 3Cs of Innovation in Low Carbon Concrete (Rocky Mountain Institute)
Skanska Zero Emissions Construction Equipment Pilot Projects
Los Angeles, California, and Stockholm, Sweden
Quick Facts
Measuring and reducing emissions from construction site activities is a growing area of interest for owners and construction firms looking to achieve net zero. While estimates vary, these emissions can contribute up to 15 percent of a project’s total embodied carbon emissions.
Developer: LA Metro (Los Angeles), City of Stockholm Other partners: Volvo CE Project type: Transit expansion (Los Angeles), site prep for master-plan development (Stockholm) Status: In progress as of 2024
Tackling these emissions can be challenging due to the lack of data and standardized methodology for measuring and reporting. However, firms including Skanska and others are working to decarbonize their construction sites by piloting all-electric heavy machinery and using equipment powered by biofuels.
In Los Angeles, Skanska conducted a 90-day pilot program of a Volvo electric excavator on the Purple (D Line) Extension Transit project for LA Metro. Results of the pilot indicate that the excavator performed all required activities while reducing carbon per hour by 66 percent (34 kilograms) and saving fuel costs. Other benefits included reduced vibration and noise, providing a healthier and more comfortable environment for workers and the surrounding community. As one of the first use cases of zero-emission heavy machinery in North America, this pilot demonstrates the impact of low-carbon construction methods, particularly for large civil megaprojects such as the Purple Line extension. In Stockholm, Skanska is working with the city of Stockholm and Volvo CE to achieve a 100 percent fossil-free construction site at the Slakthusområdet E101 development, which will transform the city’s industrial meat-packing district into a new urban neighborhood. At the project’s halfway point, Volvo reported that 1,808 tons of C02 had already been avoided through the use of electric equipment and equipment powered with hydrotreated vegetable oil. Upon completion, Skanska anticipates that the project will save well over 2,000 tons of C02 emissions, which is equivalent to the emissions from 35 trucks driving eight hours a day for a year.
Consider low-carbon structural systems and assemblies (e.g., mass timber, passive house, recycled or reused steel, or low-carbon concrete).
Mass timber can be an environmentally friendly choice when compared to traditional construction materials. Trees sequester carbon while they are growing and will continue to store carbon after they are harvested and turned into mass timber. The manufacturing process is also significantly less energy- and water-intensive compared to concrete and steel production. To learn more about mass timber, visit: WoodWorks.
Passive house is a building design standard that promotes ultra-airtight building envelopes to maintain interior temperatures and save energy. Passive house helps reduce demand on heating and cooling systems, helping avoid refrigerants and materials for MEP systems, which generally have high global warming potential. To learn more about passive house, visit: Passive House.
Recycled steel (also known as secondary steel) is a preferred choice for reducing embodied carbon. The production of recycled steel in an electric arc furnace (EAF) requires less energy compared to the manufacturing process for primary steel. Currently, the most effective way to reduce embodied carbon from steel is to use less material overall. To learn more about embodied carbon reductions in steel, see: Arup Embodied Carbon of Steel (2020)
Low-carbon concrete encompasses a broad range of innovations that aim to reduce the global warming potential of concrete mixes. These approaches might include material- or process-based solutions. Currently, the most effective way to reduce embodied carbon from concrete is to use less material overall. To learn more about innovations in low-carbon concrete, visit: RMI The 3Cs of Innovation in Low Carbon Concrete (2023)
Pacific Center
Quick Facts
San Diego, California
Developers: Harrison Street and Sterling Bay
Designer: Gensler
Size: 800,000 square feet
Project type: New construction
Status: Under construction; first phase to be completed in 2025
Pacific Center is an 800,000-square-foot life sciences campus codeveloped by Harrison Street and Sterling Bay in San Diego’s Sorrento Mesa neighborhood. The first phase of the project, which broke ground in May 2023, will include 500,000 square feet of scientific research space, a 28,000-square-foot amenity center, and a parking facility. The inclusion of low-carbon materials including recycled content steel, low-carbon concrete mixes, and mass timber is helping the project achieve an 11 percent reduction in embodied carbon compared to the baseline.
The programmatic requirements for the space, including the need to accommodate mechanical lab equipment, meant there was little flexibility to reduce embodied carbon through the building design. Despite these limitations, the project team conducted a whole building life cycle analysis to identify carbon-intensive areas of the project. During design development, the team leveraged the WBLCA results to inform the selection of systems and materials, opting to work with local material suppliers that could provide low-carbon concrete mixes and recycled steel. The project also incorporates low-carbon mass timber in the campus amenity pavilion, which will house exercise facilities and retail space. While extensive mass timber in lab and office areas was not feasible, mass timber made sense for the amenity pavilion and helped to reduce the campus’s embodied carbon by 607 metric tons of CO2.
In addition to the project’s embodied carbon accomplishments, Pacific Center features an all-electric mechanical, engineering, and plumbing system powered by rooftop solar panels, significantly reducing the building’s operational carbon emissions. The campus’s remaining buildings will be built over several phases, with anticipated completion in 2028.
Encourage tenants to seek out low-carbon fit-out materials and consider embodied carbon implications of renovations.
Consider setting GWP limits for material and equipment replacements, when EPDs are available.
Avoid “white-boxing” spaces between tenants; encourage new tenants to retain existing fit-outs when possible.
See Fitting Out Spaces for Net Zero (Urban Land Institute)
See Low Embodied Carbon Tenant Fit-Out Guide (Hudson Pacific Properties)
Consider green leases and longer tenant leases to reduce turnover.
Taking Green Leases to Net Zero (ULI)
Track and minimize construction site carbon emissions.
Track construction equipment fuel consumption per activity and material scope.
See AGC Playbook on Decarbonization and Carbon Reporting in the Construction Industry
Identify and implement strategies to reduce equipment fuel emissions, such as using electrified equipment.
Create a summary sheet for reporting and tracking of transport emissions throughout the project’s completion.
Embodied Carbon Measurement and Accounting
Update the embodied carbon assessment for the as-built project to report actual embodied carbon.
Collect as-built material quantities and embodied carbon data for the materials included in the build.
Recalculate reductions using as-built information.
Identify the highest-impact portions of the project and immediately engage project team members with design influence over these “hotspots.”
While every project is different, studies have consistently shown structure, enclosure, and MEP systems are the leading elements for new buildings, and materials with the highest contributions are typically concrete and steel.
Encourage early consideration with the structural engineer specifically around low carbon goals, optimizing structural material and bay sizes, and the low carbon concrete process.
Seek out engineering firms that have signed on to low-carbon commitments, such as:
SE2050
MEP2040.
Engage the general contractor as early as possible. Once on board, require the contractor to connect with suppliers about embodied carbon reporting.
Create a list of suppliers and subcontractors you typically specify, procure, or purchase from.
Use an online tool—such as the Embodied Carbon in Construction Calculator (EC3)
—to determine if they have product-specific EPDs.
Set up meetings with suppliers who do not have product-specific EPDs to educate them on embodied carbon.
Send an official EPD request letter to suppliers to formalize ask and build a business case. See EPD Request Letter by Building Transparency.
How to Get an EPD (Building Transparency)
Analyze material durability and performance, including aesthetic longevity, to minimize replacement cycles.
NOTE: This analysis does not necessarily provide the full picture. If a product is less durable, but is lower in embodied carbon, bio-based, circular, has a take-back program, and/or is low-toxicity, it could be a better choice.
Portland International Airport Main Terminal Expansion
Quick Facts
Portland, Oregon
When complete in early 2026, the renovation and expansion of the main terminal at the Portland International Airport (PDX) will nearly double the airport’s annual capacity while achieving a 70 percent reduction in the overall structural embodied carbon footprint when compared to building an entirely new terminal. The project is characterized by its nine-acre mass timber roof made with wood sourced entirely from forests in Oregon and Washington.
From the beginning, the project team, including the Port of Portland and design firm ZGF, envisioned the expansion as more than just a building upgrade. Instead, it became an opportunity to pay homage to the local environment and highlight the importance of sustainable materials and practices. The Port of Portland’s clear goals around sustainability informed these critical early decisions and helped avoid significant emissions from demolition and new material production. This commitment led the project team to reuse much of the airport’s existing infrastructure and integrate low-carbon mass timber into the design.
A highlight of the project is the unique mass timber roof, which celebrates Oregon’s forests while also cutting embodied carbon. In comparison to traditional construction materials like steel and concrete, the production of mass timber emits lower greenhouse gas emissions, making it a sustainable choice for new construction. In addition, the project prioritized sourcing wood from landowners who were working to restore forest ecosystems, including small landowners, community forests, and sovereign tribal lands. By sourcing locally, the project saved transportation emissions while supporting regional economies.
As a result of these commitments, around 2.5 million board feet (of the approximately 3.5 million board feet used for the roof) was sourced from forests certified by the Forest Stewardship Council (FSC) or landowners meeting the highest standards of sustainable forestry practices. This included 100 percent of the roof’s three- by six-foot lattice timbers and 95 percent of the glue-laminated mass timber (a type of mass timber product).
Developer: Port of PortlandDesigner: ZGF Other Partners: KPFF Consulting Engineers, Hoffman Skanska JV, Timberlab Size: Nine acres Project type: Renovation and expansion Status: Phase I complete; phase II anticipated completion in 2026
Kilroy Oyster Point - Phase 2
Quick Facts
South San Francisco, California
Developer: Kilroy Realty
Designer: DGA Architects
Other partners: Hathaway Dinwiddie Construction Company, Stok, Randall Lamb Associates, Magnusson Klemencic Associates, BKF Engineers, Clark Pacific
Size: 865,000 square feet (Phase 2); 3,000,000 square feet (full campus)
Project type: New construction
Status: Under construction, anticipated completion Q4 2024
Kilroy Oyster Point is a three-million-square-foot life sciences campus located in the growing South San Francisco market. Phase 2 of the 50-acre waterfront campus broke ground in 2021 and includes 865,000 square feet of office, lab space, and amenities across three towers, two amenity buildings, and a garage. The project’s pursuit of LEED Gold certification for Phase 2 spurred a focus on embodied carbon. As part of the LEED certification requirements, Kilroy engaged decarbonization consulting company Stok to perform a cradle-to-grave assessment of the project’s structure and enclosure, with a goal to surpass the required 10 percent reduction threshold for the certification. To achieve this, the team focused solely on the materials being sourced for the project and used OneClick LCA software tool to quantify the carbon footprint of different materials and components. From there, the team incorporated carbon intensity performance targets into the material specifications and construction documents. The team primarily focused on the heaviest emitters of concrete, structural steel, and curtainwall glazing, and discovered that it was relatively easy to procure products that met Kilroy’s carbon requirements. Hathaway Dinwiddie Construction Company, the project’s general contractor, observed that requiring low-carbon materials did not impact cost. This was due in part to the Bay Area’s advanced knowledge and understanding of low-carbon concrete, which made it possible to find a ready-mix supplier that could easily provide mixes with lower embodied carbon than regional averages. One challenge the team encountered was a supply chain issue that resulted in the lightweight fill on deck mix for two buildings to be swapped out for an alternative mix that had 35 percent higher global warming potential. This substitution affected the overall WBLCA results by approximately 2 percent increase in embodied carbon; however, all buildings still surpassed the 10 percent reduction threshold required for the LEED certification. In total, Phase 2 achieved a 16-percent reduction across all four buildings, with each building ranging from 14.6 percent to 17.2 percent reductions.
Hang Lung Properties Gypsum Board Recycling Programs
Shanghai and Hangzhou, China
Quick Facts
Hang Lung Properties, which develops and manages diverse properties in Hong Kong and mainland China, is embracing circularity through a partnership with two leading gypsum board suppliers—Knauf and Saint-Gobain—and an innovation partner—TRASHAUS—to pilot the recycling of waste gypsum board in two projects. By standardizing recycling processes and improving data collection, these pilot projects aim to reduce the volume of construction and demolition waste going to landfills. The scrap and surplus gypsum board will be diverted from landfills and processed for use in other applications to support a circular economy.
As of October 2024, Hang Lung, Knauf, and TRASHAUS have collected for recycling more than 1,500 pounds of Knauf’s waste gypsum board from a store fit-out renovation in Grand Gateway 66, Shanghai. Diverting these waste materials from landfill avoids the generation of hydrogen sulfide, a toxic gas, among other benefits. In addition, Hang Lung is working with Saint-Gobain on recycling gypsum scrap from the landlord area of their new construction project in Westlake 66, Hangzhou.
Gypsum board (also known as plasterboard or drywall) is a common construction material used in walls, ceilings, and partitions, and can make up a third of a fit-out project’s new materials and up to 10 percent of all demolition waste by weight. While gypsum board recycling programs have been available for many years, most gypsum is disposed of in landfills due to challenges associated with diversion and contamination. When processed correctly, gypsum waste can be recycled and turned into a number of different products, including new gypsum boards, decorative plaster, and other materials.
These efforts build upon Hang Lung’s goals for sustainable resource management, reduced carbon emissions, and less waste. The company has been monitoring the construction waste diversion rate and recycling rate at their development projects since 2022. In addition to continued monitoring, Hang Lung carried out an on-site waste study in 2024 to gain a deeper understanding of their construction waste recycling rate and practices.
Developer: Hang Lung Properties
Other partners: LVMH, Knauf, Saint-Gobain, TRASHAUS Project type: New construction and tenant improvement Status: In progress as of 2024
Track and minimize transportation carbon emissions.
Create standard supplier bid language and reporting forms.
Track material manufacturing location, distance traveled to site, mode of transportation, and fuel type.
Create a summary sheet for reporting and tracking of transport emissions throughout the project’s completion.
Set emissions targets for products and materials.
There are two main approaches for setting emission targets for products and materials:
- Set a maximum carbon footprint per unit of material, such as a cubic yard of concrete; or
- Adopt percent reduction goals from a baseline value total or per functional unit of material.
Where possible, use industry average EPDs, a baseline from the Carbon Leadership Forum (CLF), or an EC3 average to create a baseline and identify an achievable target for each material category based on available collections of EPDs.
Resources:
Embodied Carbon Toolkit for Building Owners (CLF)
Procurement Policies to Reduce Embodied Carbon (CLF)
EC3 - Embodied Carbon in Construction Calculator (Building Transparency)
Optimize design: Use less, reuse more, and design for disassembly.
Design for Disassembly
Use Less
As an industry, using less material overall is critical to carbon reduction efforts.
Designing for disassembly considers how a project's materials will be salvaged and reused after the building has reached the end of its useful life.
- Right-sizing: Evaluate programmatic requirements to optimize space use. Consider minimizing the addition of new floor area to reduce new material production.
Buildings that Last: Design for Adaptability, Deconstruction, and Reuse (AIA)
- Dematerializing: Maximize material efficiency and minimize excess. This can be achieved through the optimization of the structural systems or by selecting structural materials that can remain exposed, reducing the need for finishing materials.
Design for Disassembly in the Built Environment: A Guide to Closed-Loop Design and Building (King County)
- Reduce or eliminate below-grade parking wherever possible, particularly in certain soil conditions.
Additional Resources
AIA-CLF Toolkit for Architects - Part III: Strategies for Reducing Embodied Carbon (AIA, CLF)
Reuse More
- Include material reuse when deciding on major structure and envelope systems.
For sites and infrastructure, see Climate Positive Design Toolkit (Climate Positive Design)
- If planning to procure salvaged materials, determine what is available locally.
See the Climate Positive Design Toolkit for sites and infrastructure.
Corporate Policies
Owners and developers should integrate embodied carbon into their corporate policies to send clear and consistent communication on priorities and emissions reductions. Corporate policies can take different forms, such as the following:
Company-wide sustainability commitments, such as net zero or supply chain (purchasing) emissions reduction targets and internal carbon pricing initiatives Embodied carbon can be integrated into company sustainability action plans, annual reporting documents, and other publications.
Company-wide green building policies and initiatives, such as certification requirements, design standards, or material selection requirements for new construction or tenant fit-outs that apply across a company’s portfolio Embodied carbon requirements can be integrated into project documents, such as requests for proposals, owner project requirements, contracts, and standard specifications.
Sustainable procurement policies, such as minimum sustainability requirements for suppliers
Resources
Corporate and Building Owner Commitments to Reduce Embodied Carbon (Carbon Leadership Forum)
Embodied Carbon Procurement Policies (Carbon Leadership Forum)
Track and minimize transportation carbon emissions.
Create standard supplier bid language and reporting forms.
Track material manufacturing location, distance traveled to site, mode of transportation, and fuel type.
Create a summary sheet for reporting and tracking of transport emissions throughout the project’s completion.
Define project-level embodied carbon targets and communicate them in the owner’s project requirements.
There are two primary approaches to setting project level targets (both require
WBLCAs):
- A carbon intensity limit, which sets a maximum carbon footprint per area value for the building
- A percent reduction goal from a baseline value—either for the entire project or on a per-area basis (i.e., 10 percent reduction from baseline)
NOTE: Baselines values are not widely available in North America.
Resources:
Embodied Carbon Toolkit for Building Owners (Carbon Leadership Forum)
Embodied Carbon Benchmark Study (Carbon Leadership Forum)
Science Based Targets Initiative
Key Terms
Abbreviations
Embodied carbon: According to the Carbon Leadership Forum, embodied carbon refers to the greenhouse gas emissions generated by the manufacturing, transportation, installation, maintenance, and disposal of construction materials used in buildings, roads, and other infrastructure. Environmental Product Declaration (EPD): EPDs disclose LCA results for specific products, providing information to consumers about the environmental impact of building products. They are frequently thought of as material “nutrition labels” that report on a variety of life-cycle impacts, including global warming potential, acidification, eutrophication, ozone depletion, and smog formation.
Life cycle assessment (LCA): An LCA is an analysis that evaluates the environmental impacts of products and services, covering their life cycle from raw material extraction to waste treatment.
Whole building LCA (WBLCA): WBLCAs measure the environmental impact of a whole building. However, it’s worth noting that currently, not all “whole” building LCAs include every component of a building in their scope. Many WBLCAs only include certain elements, such as structure and enclosure, and exclude other significant components such as mechanical, engineering, and plumbing systems and interiors.
EC3: Embodied Carbon in Construction Calculator EPD: Environmental Product Declaration ESG: environmental, social, and governance GHG: greenhouse gas GIA: gross internal area GWP: global warming potential LCA: life cycle assessment LEED: Leadership in Energy and Environmental Design MEP: mechanical, engineering, and plumbing TI: tenant improvement WBLCA: whole building life cycle assessment
Refine and finalize low-carbon specifications.
Some materials are prescriptively specified (e.g., gypsum wallboard) while others are specified in a performance-based manner (e.g., concrete). Final concrete mix selection is made at construction.
The Case for Performance Based Concrete Specs (CarbonCure)
Through consultation with the project team, commit to the most feasible strategies that result in lowest embodied carbon.
Ensure selected reduction strategies are reflected in the construction drawings and project manual.
Encourage longer replacement cycles of materials.
- Assess current standards and practices for determining material replacement during a building’s use phase.
- Commit to replacement cycles based on material and product performance (versus a desired change in aesthetic) and include this in building standards.
Consider the existing portfolio as a material bank.
If you are decommissioning or deconstructing spaces, assess whether materials may be used in other new builds or as replacements in current buildings. There are many services and organizations that support material reuse, such as the following:
- Build Reuse: A national community of organizations dedicated to building material reuse
- Rheaply: A software service that supports inventory management and material reuse
- Doors Unhinged: A company specializing in reclaimed doors and other building products
- Davies Office: A company specializing in furniture remanufacturing
Track and minimize product substitutions.
Review submittals and change orders to ensure compliance with low-carbon specification criteria.
Include requirements for tracking and reducing embodied carbon in requests for proposals (RFPs) and contract language for project partners.
Include requirements for managing embodied carbon, including completing embodied carbon assessments, collecting Environmental Product Declarations (EPDs), identifying reduction opportunities, and implementing strategies.
How to Get an EPD (Building Transparency)
Provide detailed information about low-carbon products in the building’s operations and maintenance manual.
Include information about circular products, products designed for disassembly, and any products that are eligible for manufacturer take-back programs.
Consider providing a full set of deconstruction documents.
Align team members around goals for low-carbon concrete.
Hold a preconstruction meeting with the general contractor, structural engineer, architect, sustainability consultant, and ready-mix supplier to discuss low-carbon concrete expectations, goals, procurement process, and responsibilities.
Align team members around goals for low-carbon concrete.
Hold a preconstruction meeting with the general contractor, structural engineer, architect, sustainability consultant, and ready-mix supplier to discuss low-carbon concrete expectations, goals, procurement process, and responsibilities.
Salesforce Benchmarking Study for Furniture and MEP Systems
Multiple locations
Salesforce is a sustainability-minded cloud-based software company with a large and growing global real estate portfolio. To better understand the full carbon footprint of the spaces it occupies, Salesforce partnered with Brightworks Sustainability and WAP Sustainability to measure the embodied carbon emissions from furniture and mechanical, engineering, and plumbing (MEP) systems in their projects. While the industry is advancing rapidly, embodied carbon data for furniture and MEP systems is lacking, and the categories are rarely included in most whole building life cycle assessments.
To address this lack of data, Brightworks and WAP developed a methodology that could be followed to determine an embodied carbon factor for a wide range of products; those with Environmental Product Declarations (EPDs) and those without. The team then applied the methodology to a tenant improvement (TI) project that was representative of a typical Salesforce workplace. Using material data collected from each subcontractor on the project, the sustainability teams discovered that combined, MEP systems and furniture contributed about 68 percent of the project’s total embodied carbon emissions.
The market for low-embodied-carbon furniture and MEP systems products is growing, but stronger demand signals from the development community are needed to push manufacturers to procure EPDs for their products. In the meantime, real estate stakeholders can seek out opportunities to reuse as many interior products as possible. A host of asset management tools, logistics companies, and other organizations are making it easier for owners and lessors to repair, refurbish, reuse interior products. These avenues are helping companies reduce their environmental impact and, in many cases, save costs from new product procurement.
Quick Facts
Developer: Salesforce
Other partners: Brightworks Sustainability, WAP Sustainability
Project type: Tenant improvements
Status: Completed 2023
Embodied Carbon Measurement and Accounting
Refine the project’s embodied carbon estimate based on the building’s design and material selection.
Using materials and quantities specified by design, reconduct the embodied carbon assessment.
Useful tools at this stage include the following:
EC3 - Embodied Carbon in Construction Calculator (Building Transparency)
One Click LCA
tallyCAT
Track and minimize construction site carbon emissions.
Track construction equipment fuel consumption per activity and material scope.
See AGC Playbook on Decarbonization and Carbon Reporting in the Construction Industry
Identify and implement strategies to reduce equipment fuel emissions, such as using electrified equipment.
Create a summary sheet for reporting and tracking of transport emissions throughout the project’s completion.
Create low-carbon specifications that require EPDs for all components considered and tracked for embodied carbon reduction. Start with structural materials, such as concrete, steel, and wood at a minimum.
Include intentions for salvaged materials, circular materials, and materials with manufacturer take-back programs.
Reach out to suppliers to check on low-carbon product availability.
If selected products do not have an EPD, send an official EPD request letter to suppliers to formalize ask and build a business case.
Download an EPD Request Letter (Building Transparency)
How to Get an EPD (Building Transparency)
Encourage longer replacement cycles of materials.
Assess current standards and practices for determining material replacement during a building’s use phase.
Commit to replacement cycles based on material and product performance (versus a desired change in aesthetic) and include this in building standards.
The Gilbert
London, England
Quick Facts
At The Gilbert in London, Brookfield Properties transformed a historic building into a sustainable office space that honors the past while looking ahead to the future. A critical decision to retain 90 percent of the original structure helped the project achieve an 80 percent reduction in embodied carbon emissions when compared to demolishing and constructing a new building.
The seven-story building, originally built in 1930 as a private members club by Sir Giles Gilbert Scott, now serves as the first Brookfield Properties building to achieve net zero in construction in line with the U.K. Green Building Council framework. To meet the requirements, the project team conducted a whole-life carbon assessment to understand the building’s impact. Sustainability consulting company Hilson Moran carried out the study during schematic design to evaluate the carbon intensity of different design options. The assessment revealed that significant carbon savings could be achieved by avoiding demolition and retaining the building’s structure, including the historic facade and architectural features.
Specifically, the team opted to refurbish and reseal the original windows instead of replacing them, helping to save carbon while preserving one of the building’s most distinctive elements. Another modification included leaving the ceilings exposed to save carbon emissions from finishing materials. Brookfield Properties reported that these changes were essential for reducing embodied carbon as well as for saving substantial construction costs and shortening the development timeline.
In total, the project’s embodied carbon emissions came in at 2,182 tons of carbon [based on 147 kg CO2e/m2 gross internal area (GIA)], beating the LETI Office Benchmark by 9,500 tons. Brookfield discovered that they could renovate the Gilbert seven times before it reached the same embodied carbon as one standard new office build of the same size (estimated at 1,000 kg CO2e/m2 GIA).
Developer: Brookfield Properties
Designer: Stiff + Trevillion
Other partners: Mace
Size: 119,000 square feet
Project type: Renovation
Status: Completed 2021
Main_Embodied Carbon Timeline
ULI
Created on September 10, 2024
Intervention Points for Building Greener
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The Developer's Guide to Embodied Carbon
Intervention Points for Building Greener
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Corporate Policies
Concept
Design
Construction
Operations
End of Life
Key Terms and Abbreviations
Concept
Design
Construction
Operations
End of Life
HOME
Early Visioning
Early Visioning Interventions
Project Example
Portland International Airport Main Terminal Expansion
Click
below for more detail
Portland, Oregon
Define a big-picture vision for embodied carbon reductions and environmental, social, and governance (ESG) goals.
Read more
Determine applicable green building certifications that focus on materials. The certification program can help define the project-level embodied carbon target.
Measurement and Accounting
Include requirements for tracking and reducing embodied carbon in requests for proposals (RFPs) and contract language for project partners.
Commit to conducting a whole building life cycle assessment (WBLCA) to assess the embodied carbon impact of the project.
Establish internal systems for accountability. Identify embodied carbon champions for each relevant discipline on the project team.
Read more
Concept
Design
Construction
Operations
End of Life
HOME
Pre-Design
Construction Documents
Schematic Design
Design Development
Pre-Design Interventions
Project Example
80 M Street SE
Click
below for more detail
Washington, DC
Define project-level embodied carbon targets and communicate them in the owner’s project requirements.
Read more
Consider low-carbon structural systems and assemblies (e.g., mass timber, passive house, reused steel, or low-carbon concrete).
Measurement and Accounting
Optimize design: Use less, reuse more, and design for disassembly.
Continue revisiting and refining the building LCA benchmark as needed.
Engage the general contractor as early as possible. Once on board, require the contractor to connect with suppliers about embodied carbon reporting.
Concept
Design
Construction
Operations
End of Life
HOME
Pre-Design
Construction Documents
Schematic Design
Design Development
Schematic Design Interventions
Project Example
Click
below for more detail
The Gilbert
Identify the highest-impact portions of the project and immediately engage project team members with design influence over these “hotspots.”
London, England
Read more
Continue optimizing design to use less, reuse more, and design for disassembly.
Measurement and Accounting
Conduct a preliminary embodied carbon assessment using schematic design details.
Ensure a deconstruction assessment is included in the budget and project requirements (see Occupancy).
Read more
See EPA Deconstruction Rapid Assessment Tool
Concept
Design
Construction
Operations
End of Life
HOME
Pre-Design
Construction Documents
Schematic Design
Design Development
Design Development Interventions
Project Example
Click
below for more detail
Pacific Center
Analyze material durability and performance, including aesthetic longevity, to minimize replacement cycles.
San Diego, California
Read more
Work with the engineering team to reduce embodied carbon in MEP systems.
Measurement and Accounting
Create low-carbon specifications that require Environmental Product Declarations for all components considered and tracked for embodied carbon reduction. Start with structural materials, such as concrete, steel, and wood at a minimum.
Use embodied carbon assessment results (alongside cost) to inform the selection of systems and materials.
Read more
Concept
Design
Construction
Operations
End of Life
HOME
Pre-Design
Construction Documents
Schematic Design
Design Development
Construction Documents Interventions
Project Example
Kilroy Oyster Point
Click
below for more detail
South San Francisco, California
Set emissions targets for products and materials.
Read more
Refine and finalize low-carbon specifications.
Measurement and Accounting
Refine the project’s embodied carbon estimate based on the building’s design and material selection.
Read more
Concept
Design
Construction
Operations
End of Life
HOME
Bidding/Pricing (Procurement)
Construction Administration
Bidding/Pricing (Procurement) Interventions
Project Example
Metropolitan Park (Amazon HQ2)
Click
below for more detail
Arlington, Virginia
Read more
Create low-carbon bid documents.
Where possible, use embodied carbon data alongside cost data to inform selection of bidders.
Align team members around goals for low-carbon concrete.
Concept
Design
Construction
Operations
End of Life
HOME
Bidding/Pricing (Procurement)
Construction Administration
Construction Administration
Construction Administration Interventions
Project Example
Skanska Zero Emissions Construction Equipment Pilot
Click
below for more detail
Los Angeles, California and Stockholm, Sweden
Track and minimize transportation carbon emissions.
Read more
Track and minimize construction site carbon emissions.
Track and minimize construction waste.
Measurement and Accounting
Update the embodied carbon assessment for the as-built project to report actual embodied carbon.
Track and minimize product substitutions.
Ensure preceding steps are noted in pricing.
Read more
Concept
Design
Construction
Operations
End of Life
HOME
Occupancy
Occupancy Interventions
Project Example
Salesforce Benchmarking Study for Furniture and MEP Systems
Click
below for more detail
Multiple Locations
Provide detailed information about low-carbon products in the building’s operations and maintenance manual.
Read more
Encourage longer replacement cycles of materials.
Work with facilities and maintenance teams to monitor and reduce refrigerant leakage.
Encourage tenants to seek out low-carbon fit-out materials and consider embodied carbon implications of renovations.
Consider green leases and longer tenant leases to reduce turnover.
Concept
Design
Construction
Operations
End of Life
HOME
Circularity & Material Reuse
Circularity & Material Reuse Interventions
Project Example
Hang Lung Properties Gypsum Board Recycling Programs
Click
below for more detail
Consider the existing portfolio as a material bank. If you are decommissioning or deconstructing spaces, assess whether materials may be used in other new builds or as replacements in current buildings.
Shanghai and Hangzhou, China
Read more
Promote a circular economy; opt for deconstruction to preserve materials for reuse, including both structural/envelope materials and interior materials.
Gather lessons learned at the end of each project and use them to regularly update corporate policies and design, procurement, and construction standards.
Define project-level embodied carbon targets and communicate them in the owner’s project requirements.
There are two primary approaches to setting project level targets (both require WBLCAs):
NOTE: Baselines values are not widely available in North America.
Resources:
Embodied Carbon Toolkit for Building Owners (Carbon Leadership Forum)
Embodied Carbon Benchmark Study (Carbon Leadership Forum)
Science Based Targets Initiative
Where possible, use embodied carbon data alongside cost data to inform selection of bidders.
Create a standard bid leveling tracker that includes embodied carbon data including fields for if bidder provided EPD, if bidder commits to providing EPD by end of construction, or if bidder would charge the project for the EPD cost.
How to Get an EPD (Building Transparency)
Consider the existing portfolio as a material bank.
If you are decommissioning or deconstructing spaces, assess whether materials may be used in other new builds or as replacements in current buildings. There are many services and organizations that support material reuse, such as the following:
Build Reuse: A national community of organizations dedicated to building material reuse
Rheaply: A software service that supports inventory management and material reuse
Doors Unhinged: A company specializing in reclaimed doors and other building products
Davies Office: A company specializing in furniture remanufacturing
Promote a circular economy; opt for deconstruction to preserve materials for reuse, including both structural/envelope materials and interior materials.
Refine and finalize low-carbon specifications.
Some materials are prescriptively specified (e.g., gypsum wallboard) while others are specified in a performance-based manner (e.g., concrete). Final concrete mix selection is made at construction.
The Case for Performance Based Concrete Specs (CarbonCure)
Through consultation with the project team, commit to the most feasible strategies that result in lowest embodied carbon.
Ensure selected reduction strategies are reflected in the construction drawings and project manual.
Create low-carbon bid documents.
Include the overall project embodied carbon reduction target alongside material-specific limits.
Create standard embodied carbon bid language for included material categories to inform suppliers of request for or requirement of EPDs.
See model bid document language (Building Transparency).
Require contractors and subcontractors to limit equipment idling time, use Tier IV equipment, and track fuel consumption of construction machinery.
Ask for estimated transportation carbon emissions.
Ask for estimated construction site carbon emissions.
Track and minimize construction waste.
Track construction waste, including the diversion rate.Source separate waste for major material streams to enable a higher recycling rate. When creating a demolition plan, look for opportunities for deconstruction and salvage materials where possible. Require high percentage construction waste diversion from landfill in project requirements and contracts for general contractors. Include desire or requirement for a certain percentage of material salvage for reuse and/or commit to manufacturer materials take-back programs if demolishing an existing building.
Engage the general contractor as early as possible. Once on board, require the contractor to connect with suppliers about embodied carbon reporting.
Create a list of suppliers and subcontractors you typically specify, procure, or purchase from.
Use an online tool—such as the Embodied Carbon in Construction Calculator (EC3)
—to determine if they have product-specific EPDs.
Set up meetings with suppliers who do not have product-specific EPDs to educate them on embodied carbon.
Send an official EPD request letter to suppliers to formalize ask and build a business case. See EPD Request Letter by Building Transparency.
How to Get an EPD (Building Transparency)
Track and minimize construction waste.
Track construction waste, including the diversion rate.Source separate waste for major material streams to enable a higher recycling rate. When creating a demolition plan, look for opportunities for deconstruction and salvage materials where possible. Require high percentage construction waste diversion from landfill in project requirements and contracts for general contractors. Include desire or requirement for a certain percentage of material salvage for reuse and/or commit to manufacturer materials take-back programs if demolishing an existing building.
Optimize design: Use less, reuse more, and design for disassembly.
Use Less
Design for Disassembly
As an industry, using less material overall is critical to carbon reduction efforts.
Designing for disassembly considers how a project's materials will be salvaged and reused after the building has reached the end of its useful life.
Buildings that Last: Design for Adaptability, Deconstruction, and Reuse (AIA)
Design for Disassembly in the Built Environment: A Guide to Closed-Loop Design and Building (King County)
Additional Resources
AIA-CLF Toolkit for Architects - Part III: Strategies for Reducing Embodied Carbon
Reuse More
For sites and infrastructure, see Climate Positive Design Toolkit (Climate Positive Design)
Optimize design: Use less, reuse more, and design for disassembly.
Use Less
Design for Disassembly
As an industry, using less material overall is critical to carbon reduction efforts.
Designing for disassembly considers how a project's materials will be salvaged and reused after the building has reached the end of its useful life.
Buildings that Last: Design for Adaptability, Deconstruction, and Reuse (AIA)
Design for Disassembly in the Built Environment: A Guide to Closed-Loop Design and Building (King County)
Additional Resources
AIA-CLF Toolkit for Architects - Part III: Strategies for Reducing Embodied Carbon
Reuse More
For sites and infrastructure, see Climate Positive Design Toolkit (Climate Positive Design)
Engage the general contractor as early as possible. Once on board, require the contractor to connect with suppliers about embodied carbon reporting.
Create a list of suppliers and subcontractors you typically specify, procure, or purchase from.
Use an online tool—such as the Embodied Carbon in Construction Calculator (EC3)
—to determine if they have product-specific
EPDs.
Set up meetings with suppliers who do not have product-specific EPDs to educate them on embodied carbon.
Send an official EPD request letter to suppliers to formalize ask and build a business case. See EPD Request Letter by Building Transparency.
How to Get an EPD (Building Transparency)
Determine applicable green building certifications that focus on materials. The certification program can help define the project-level embodied carbon target.
Popular sustainability certification programs:
Leadership in Energy and Environmental Design (LEED)
International Living Future Institute (ILFI) Zero Carbon
International Living Future Institute (ILFI) Living Building Challenge
Resource:
Comparing Building Standards from Around the World v2.0 (RESET)
Provide detailed information about low-carbon products in the building’s operations and maintenance manual.
Include information about circular products, products designed for disassembly, and any products that are eligible for manufacturer take-back programs.
Consider providing a full set of deconstruction documents.
Track and minimize product substitutions.
Review submittals and change orders to ensure compliance with low-carbon specification criteria.
Work with the engineering team to reduce embodied carbon in MEP systems.
NOTE: Many WBLCAs omit emissions from MEP systems. More research and data are needed on MEP systems and their contribution to a new building’s embodied carbon.
If possible, avoid refrigerants. If refrigerants must be used, request low global warming potential (GWP) refrigerants.
Resources:
Life Cycle Assessment of Mechanical, Electrical, and Plumbing in Commercial Office Buildings (CLF)
MEP2040
Consider the existing portfolio as a material bank.
If you are decommissioning or deconstructing spaces, assess whether materials may be used in other new builds or as replacements in current buildings. There are many services and organizations that support material reuse, such as the following:
Build Reuse: A national community of organizations dedicated to building material reuse
Rheaply: A software service that supports inventory management and material reuse
Doors Unhinged: A company specializing in reclaimed doors and other building products
Davies Office: A company specializing in furniture remanufacturing
Track and minimize product substitutions.
Review submittals and change orders to ensure compliance with low-carbon specification criteria.
Optimize design: Use less, reuse more, and design for disassembly.
Design for Disassembly
Use Less
As an industry, using less material overall is critical to carbon reduction efforts.
Designing for disassembly considers how a project's materials will be salvaged and reused after the building has reached the end of its useful life.
Buildings that Last: Design for Adaptability, Deconstruction, and Reuse (AIA)
Design for Disassembly in the Built Environment: A Guide to Closed-Loop Design and Building (King County)
Additional Resources
AIA-CLF Toolkit for Architects - Part III: Strategies for Reducing Embodied Carbon (AIA, CLF)
Reuse More
For sites and infrastructure, see Climate Positive Design Toolkit (Climate Positive Design)
See the Climate Positive Design Toolkit for sites and infrastructure.
Where possible, use embodied carbon data alongside cost data to inform selection of bidders.
Create a standard bid leveling tracker that includes embodied carbon data including fields for if bidder provided EPD, if bidder commits to providing EPD by end of construction, or if bidder would charge the project for the EPD cost.
How to Get an EPD (Building Transparency)
Define a big-picture vision for embodied carbon reductions and environmental, social, and governance (ESG) goals.
Determine how the project fits into your company’s overall embodied carbon reduction goals and ESG strategies.
Consider if reusing or renovating an existing building might fulfill project requirements. (Ask: do we need to build?)
Determine applicable green building certifications that focus on materials. The certification program can help define the project-level embodied carbon target.
Popular sustainability certification programs:
Leadership in Energy and Environmental Design (LEED)
International Living Future Institute (ILFI) Zero Carbon
International Living Future Institute (ILFI) Living Building Challenge
Resource:
Comparing Building Standards from Around the World v2.0 (RESET)
Track and minimize transportation carbon emissions.
Create standard supplier bid language and reporting forms.
Track material manufacturing location, distance traveled to site, mode of transportation, and fuel type.
Create a summary sheet for reporting and tracking of transport emissions throughout the project’s completion.
Set emissions targets for products and materials.
There are two main approaches for setting emission targets for products and materials:
Where possible, use industry average EPDs, CLF baselines, or an EC3 average to create a baseline and identify an achievable target for each material category based on available collections of EPDs.
Resources:
Embodied Carbon Toolkit for Building Owners (CLF)
Procurement Policies to Reduce Embodied Carbon (CLF)
EC3 - Embodied Carbon in Construction Calculator (Building Transparency)
Consider low-carbon structural systems and assemblies (e.g., mass timber, passive house, recycled or reused steel, or low-carbon concrete).
Mass timber can be an environmentally friendly choice when compared to traditional construction materials. Trees sequester carbon while they are growing and will continue to store carbon after they are harvested and turned into mass timber. The manufacturing process is also significantly less energy- and water-intensive compared to concrete and steel production. To learn more about mass timber, visit: WoodWorks.
Passive house is a building design standard that promotes ultra-airtight building envelopes to maintain interior temperatures and save energy. Passive house helps reduce demand on heating and cooling systems, helping avoid refrigerants and materials for MEP systems, which generally have high global warming potential. To learn more about passive house, visit: Passive House.
Recycled steel (also known as secondary steel) is a preferred choice for reducing embodied carbon. The production of recycled steel in an electric arc furnace (EAF) requires less energy compared to the manufacturing process for primary steel. Currently, the most effective way to reduce embodied carbon from steel is to use less material overall. To learn more about embodied carbon reductions in steel, see: Arup Embodied Carbon of Steel (2020)
Low-carbon concrete encompasses a broad range of innovations that aim to reduce the global warming potential of concrete mixes. These approaches might include material- or process-based solutions. Currently, the most effective way to reduce embodied carbon from concrete is to use less material overall. To learn more about innovations in low-carbon concrete, visit: RMI The 3Cs of Innovation in Low Carbon Concrete (2023)
Work with the engineering team to reduce embodied carbon in MEP systems.
NOTE: Many WBLCAs omit emissions from mechanical, engineering, and plumbing (MEP) systems. More research and data are needed on MEP systems and their contribution to a new building’s embodied carbon.
If possible, avoid refrigerants. If refrigerants must be used, request low global warming potential (GWP) refrigerants.
Resources:
Life Cycle Assessment of Mechanical, Electrical, and Plumbing in Commercial Office Buildings (CLF)
MEP 2040
Work with facilities and maintenance teams to monitor and reduce refrigerant leakage.
See Refrigerant Management (Project Drawdown)
Work with facilities and maintenance teams to monitor and reduce refrigerant leakage.
Include requirements for tracking and reducing embodied carbon in requests for proposals (RFPs) and contract language for project partners.
Include requirements for managing embodied carbon, including completing embodied carbon assessments, collecting Environmental Product Declarations (EPDs), identifying reduction opportunities, and implementing strategies.
How to Get an EPD (Building Transparency)
Include requirements for tracking and reducing embodied carbon in requests for proposals (RFPs) and contract language for project partners.
Include requirements for managing embodied carbon, including completing embodied carbon assessments, collecting Environmental Product Declarations (EPDs), identifying reduction opportunities, and implementing strategies.
How to Get an EPD (Building Transparency)
Metropolitan Park (Amazon HQ2)
Quick Facts
Arlington, Virginia
Developers: Amazon and JBG Smith Designer: ZGF Other partners: Thornton Tomasetti (structural), GHT (MEP), Clark Construction (general contractor), Seneca Group (owner’s representative and development manager) Size: 2.1 million square feet Project type: New construction Status: Completed
Amazon’s second headquarters in Arlington, Virginia, exemplifies the company’s commitment to sustainability through reductions in both embodied and operational carbon. Partnerships between the design team, general contractor, and suppliers were integral to the project’s success. Amazon specified its embodied carbon reduction goals in its contracts with project partners, signaling its commitment to low-carbon construction and setting the stage for embodied carbon reductions during the procurement phase. To meet their goals, the project team adopted performance-based specifications for the concrete and empowered producers to use a variety of methods for reducing carbon in their designs. Compared to traditional prescriptive specifications that require certain ratios of cement for concrete mixes, performance-based specifications give suppliers the freedom to create mixes based on performance criteria for the application. At Met Park, this approach allowed suppliers to leverage different technologies and meet both the project’s structural requirements and embodied carbon reduction goals. A collaborative approach to procurement and meticulous attention to life cycle emissions helped the 2.1-million-square-foot project achieve a 20 percent reduction in the embodied carbon of its concrete structures compared to the industry baseline. This saved over 14,700 metric tons of carbon, or the equivalent of taking more than 3,200 cars off the road for an entire year. The project also integrated concrete made with CarbonCure, a technology that injects recycled carbon dioxide into concrete, increasing the strength of the mix while reducing embodied carbon. The CarbonCure technology has since been used at over 40 other Amazon global construction sites along with many other low-carbon concrete solutions within the company’s global portfolio. Met Park also integrated other low-carbon building materials such as mass timber to further drive down embodied carbon. A mass timber ceiling in the meeting center features cross-laminated timber and glue-laminated timber beams, providing not just aesthetic value but also carbon reduction benefits, as wood absorbs carbon as it grows and continues to store that carbon throughout its material life cycle in the building. Together, these strategies helped Amazon’s HQ2 achieve significant carbon reductions as well as LEED v4 Platinum certification, making it the largest newly constructed building and LEED V4 BD+C project to achieve this recognition.
Identify the highest-impact portions of the project and immediately engage project team members with design influence over these “hotspots.”
While every project is different, studies have consistently shown structure, enclosure, and MEP systems are the leading elements for new buildings, and materials with the highest contributions are typically concrete and steel.
Encourage early consideration with the structural engineer specifically around low carbon goals, optimizing structural material and bay sizes, and the low carbon concrete process.
Seek out engineering firms that have signed on to low-carbon commitments, such as:
SE2050
MEP 2040
Refine and finalize low-carbon specifications.
Some materials are prescriptively specified (e.g., gypsum wallboard) while others are specified in a performance-based manner (e.g., concrete). Final concrete mix selection is made at construction.
The Case for Performance Based Concrete Specs (CarbonCure)
Through consultation with the project team, commit to the most feasible strategies that result in lowest embodied carbon.
Ensure selected reduction strategies are reflected in the construction drawings and project manual.
Track and minimize construction site carbon emissions.
Track construction equipment fuel consumption per activity and material scope.
AGC Playbook on Decarbonization and Carbon Reporting in the Construction Industry
Identify and implement strategies to reduce equipment fuel emissions, such as using electrified equipment.
Create a summary sheet for reporting and tracking of transport emissions throughout the project’s completion.
Determine applicable green building certifications that focus on materials. The certification program can help define the project-level embodied carbon target.
Popular sustainability certification programs:
Leadership in Energy and Environmental Design (LEED)
International Living Future Institute (ILFI) Zero Carbon
International Living Future Institute (ILFI) Living Building Challenge
Resource:
Comparing Building Standards from Around the World v2.0 (RESET)
Encourage tenants to seek out low-carbon fit-out materials and consider embodied carbon implications of renovations.
Consider setting GWP limits for material and equipment replacements, when EPDs are available.
Avoid “white-boxing” spaces between tenants; encourage new tenants to retain existing fit-outs when possible.
Fitting Out Spaces for Net Zero (ULI)
Low Embodied Carbon Tenant Fit-Out Guide (Hudson Pacific Properties)
Track and minimize construction waste.
Track construction waste, including the diversion rate.Source separate waste for major material streams to enable a higher recycling rate. When creating a demolition plan, look for opportunities for deconstruction and salvage materials where possible. Require high percentage construction waste diversion from landfill in project requirements and contracts for general contractors. Include desire or requirement for a certain percentage of material salvage for reuse and/or commit to manufacturer materials take-back programs if demolishing an existing building.
Consider green leases and longer tenant leases to reduce turnover.
Provide detailed information about low-carbon products in the building’s operations and maintenance manual.
Include information about circular products, products designed for disassembly, and any products that are eligible for manufacturer take-back programs.
Consider providing a full set of deconstruction documents.
Optimize design: Use less, reuse more, and design for disassembly.
Use Less
Design for Disassembly
As an industry, using less material overall is critical to carbon reduction efforts.
Designing for disassembly considers how a project's materials will be salvaged and reused after the building has reached the end of its useful life.
Buildings that Last: Design for Adaptability, Deconstruction, and Reuse (AIA)
Design for Disassembly in the Built Environment: A Guide to Closed-Loop Design and Building (King County)
Additional Resources
AIA-CLF Toolkit for Architects - Part III: Strategies for Reducing Embodied Carbon
Reuse More
For sites and infrastructure, see Climate Positive Design Toolkit (Climate Positive Design)
Create low-carbon bid documents.
Include the overall project embodied carbon reduction target alongside material-specific limits.
Create standard embodied carbon bid language for included material categories to inform suppliers of request for or requirement of EPDs.
See model bid document language (Building Transparency).
Require contractors and subcontractors to limit equipment idling time, use Tier IV equipment, and track fuel consumption of construction machinery.
Ask for estimated transportation carbon emissions.
Ask for estimated construction site carbon emissions.
Consider green leases and longer tenant leases to reduce turnover.
See Taking Green Leases to Net Zero (ULI)
Embodied Carbon Measurement and Accounting
Conduct a preliminary
embodied carbon assessment
using schematic design details.
Resources:
AIA-CLF Embodied Carbon Toolkit for Architects Part II: Measuring Embodied Carbon
Tools for Measuring Embodied Carbon (CLF)
Create low-carbon specifications that require EPDs for all components considered and tracked for embodied carbon reduction. Start with structural materials, such as concrete, steel, and wood at a minimum.
Include intentions for salvaged materials, circular materials, and materials with manufacturer take-back programs.
Reach out to suppliers to check on low-carbon product availability.
If selected products do not have an EPD, send an official EPD request letter to suppliers to formalize ask and build a business case.
Download an EPD Request Letter (Building Transparency)
How to Get an EPD (Building Transparency)
80 M Street SE
Washington, DC
Quick Facts
At 80 M Street SE, developer Columbia Property Trust added a vertical mass timber extension to an existing seven-story concrete building in the heart of Washington, D.C.’s Navy Yard neighborhood. The three-floor addition delivers 104,000 square feet of trophy-class office space and nearly 4,000 square feet of outdoor amenity space. Overbuilds offer a creative approach for adding square footage while minimizing the environmental impacts from demolishing and constructing a new building. 80 M is the first commercial office building in D.C. to feature a vertical extension constructed of mass timber. The project exemplifies how smart decision-making in early design phases can result in significant embodied carbon savings. In pre-design, Columbia Property Trust supported an initial study of the mass timber option because of the material’s reduced density (relative to other superstructure materials), aesthetic qualities, lower carbon footprint, reduced schedule of on-site activities, and potential for differentiating 80 M from standard class A office buildings in the neighborhood. When the option proved feasible, the design team established mass timber as the Basis of Design.* This was critical for ensuring that mass timber would be seriously considered as a viable option for the extension. The cost of mass timber was comparable to the conventional steel option and only carried a slight premium, which was offset by higher per-square-foot lease rates and an overall faster lease-up. In addition, contractor DAVIS solicited multiple bids on mass timber to collect competitive pricing, further enabling the material to be financially viable. Once the selected mass timber contractor was on board, DAVIS managed the process of working through the final construction details to ensure the design could be implemented successfully. In total, the mass timber option resulted in a 40 percent reduction in cradle-to-grave structural embodied carbon compared to a standard structural system of concrete and steel.
Developer: Columbia Property Trust Designer: Hickok Cole Architects Other partners: Arup, DAVIS Size: 104,000 square feet (overbuild only) Project type: Renovation and expansion Status: Completed February 2022
* The Basis of Design documents the principles, assumptions, rationale, criteria, and considerations used for calculations and decisions during design.
Optimize design: Use less, reuse more, and design for disassembly.
Design for Disassembly
Use Less
As an industry, using less material overall is critical to carbon reduction efforts.
Designing for disassembly considers how a project's materials will be salvaged and reused after the building has reached the end of its useful life.
Buildings that Last: Design for Adaptability, Deconstruction, and Reuse (AIA)
Design for Disassembly in the Built Environment: A Guide to Closed-Loop Design and Building (King County)
Additional Resources
AIA-CLF Toolkit for Architects - Part III: Strategies for Reducing Embodied Carbon (AIA, CLF)
Reuse More
For sites and infrastructure, see Climate Positive Design Toolkit (Climate Positive Design)
See the Climate Positive Design Toolkit for sites and infrastructure.
Encourage tenants to seek out low-carbon fit-out materials and consider embodied carbon implications of renovations.
Where possible, use embodied carbon data alongside cost data to inform selection of bidders.
Create a standard bid leveling tracker that includes embodied carbon data including fields for if bidder provided EPD, if bidder commits to providing EPD by end of construction, or if bidder would charge the project for the EPD cost.
How to Get an EPD (Building Transparency)
Encourage longer replacement cycles of materials.
Assess current standards and practices for determining material replacement during a building’s use phase.
Commit to replacement cycles based on material and product performance (versus a desired change in aesthetic) and include this in building standards.
Analyze material durability and performance, including aesthetic longevity, to minimize replacement cycles.
NOTE: This analysis does not necessarily provide the full picture. If a product is less durable, but is lower in embodied carbon, bio-based, circular, has a take-back program, and/or is low-toxicity, it could be a better choice.
Define a big-picture vision for embodied carbon reductions and environmental, social, and governance (ESG) goals.
Determine how the project fits into your company’s overall embodied carbon reduction goals and ESG strategies.
Consider if reusing or renovating an existing building might fulfill project requirements. (Ask: do we need to build?)
Create low-carbon specifications that require Environmental Product Declarations (EPDs) for all components considered and tracked for embodied carbon reduction. Start with structural materials, such as concrete, steel, and wood at a minimum.
Include intentions for salvaged materials, circular materials, and materials with manufacturer take-back programs.
Reach out to suppliers to check on low-carbon product availability.
If selected products do not have an EPD, send an official EPD request letter to suppliers to formalize ask and build a business case.
Download an EPD Request Letter (Building Transparency)
How to Get an EPD (Building Transparency)
Promote a circular economy; opt for deconstruction to preserve materials for reuse, including both structural/envelope materials and interior materials.
If the existing building cannot be reused, conduct a deconstruction survey to identify all building materials that can be salvaged for reuse on new project, reused on a different project, or sent to a manufacturer take-back program.
Look for opportunities to reuse or salvage materials in future projects.
Take advantage of manufacturer materials take-back programs if demolishing a building.
Define project-level embodied carbon targets and communicate them in the owner’s project requirements.
There are two primary approaches to setting project level targets (both require WBLCAs):
NOTE: Baselines values are not widely available in North America.
Resources:
Embodied Carbon Toolkit for Building Owners (Carbon Leadership Forum)
Embodied Carbon Benchmark Study (Carbon Leadership Forum)
Science Based Targets Initiative
Promote a circular economy; opt for deconstruction to preserve materials for reuse, including both structural/envelope materials and interior materials.
If the existing building cannot be reused, conduct a deconstruction survey to identify all building materials that can be salvaged for reuse on new project, reused on a different project, or sent to a manufacturer take-back program.
Look for opportunities to reuse or salvage materials in future projects.
Take advantage of manufacturer materials take-back programs if demolishing a building.
Create low-carbon bid documents.
Include the overall project embodied carbon reduction target alongside material-specific limits.
Create standard embodied carbon bid language for included material categories to inform suppliers of request for or requirement of EPDs.
Model bid document language (Building Transparency)
Require contractors and subcontractors to limit equipment idling time, use Tier IV equipment, and track fuel consumption of construction machinery.
Ask for estimated transportation carbon emissions.
Ask for estimated construction site carbon emissions.
Analyze material durability and performance, including aesthetic longevity, to minimize replacement cycles.
NOTE: This analysis does not necessarily provide the full picture. If a product is less durable, but is lower in embodied carbon, bio-based, circular, has a take-back program, and/or is low-toxicity, it could be a better choice.
Work with facilities and maintenance teams to monitor and reduce refrigerant leakage.
Refrigerant Management (Project Drawdown)
Identify the highest-impact portions of the project and immediately engage project team members with design influence over these “hotspots.”
While every project is different, studies have consistently shown structure, enclosure, and MEP systems are the leading elements for new buildings, and materials with the highest contributions are typically concrete and steel.
Encourage early consideration with the structural engineer specifically around low carbon goals, optimizing structural material and bay sizes, and the low carbon concrete process.
Seek out engineering firms that have signed on to low-carbon commitments, such as:
SE2050
MEP2040.
Work with the engineering team to reduce embodied carbon in MEP systems.
NOTE: Many WBLCAs omit emissions from MEP systems. More research and data are needed on MEP systems and their contribution to a new building’s embodied carbon.
If possible, avoid refrigerants. If refrigerants must be used, request low global warming potential (GWP) refrigerants.
Resources:
Life Cycle Assessment of Mechanical, Electrical, and Plumbing in Commercial Office Buildings (CLF)
MEP2040
Embodied Carbon Measurement and Accounting
Use
results (alongside cost) to inform the selection of systems and materials.
embodied carbon assessment
Run material and system options through an embodied carbon assessment tool to understand associated emission data for each option. Compare embodied carbon data alongside cost to inform decision making.
Calculate the embodied carbon avoidance potential of identified strategies and investigate any performance, cost, or schedule tradeoffs.
Continue to evaluate high-impact material categories and available emissions reductions.
Factor in transportation emissions. Consider tradeoffs between product-level emissions and transportation emissions.
Resources:
AIA-CLF Embodied Carbon Toolkit for Architects Part II: Measuring Embodied Carbon
Tools for Measuring Embodied Carbon (CLF)
Define a big-picture vision for embodied carbon reductions and environmental, social, and governance (ESG) goals.
Determine how the project fits into your company’s overall embodied carbon reduction goals and ESG strategies.
Consider if reusing or renovating an existing building might fulfill project requirements. (Ask: do we need to build?)
Embodied Carbon Measurement and Accounting
Commit to conducting a whole building life cycle assessment (WBLCA) to assess the embodied carbon impact of the project.
Similar to energy modeling, architects (or their consultants) should perform WBLCAs throughout the design process to actively inform the design of a building.
Resources:
Benchmarking
Embodied Carbon Benchmark Study (CLF)
Science Based Targets Initiative
Measurement
AIA-CLF Embodied Carbon Toolkit for Architects Part II: Measuring Embodied Carbon
Tools for Measuring Embodied Carbon (CLF)
Tools
EPIC: Early Phase Integrated Carbon Assessment
CARE: Carbon Avoided Retrofit Estimator
Align team members around goals for low-carbon concrete.
Hold a preconstruction meeting with the general contractor, structural engineer, architect, sustainability consultant, and ready-mix supplier to discuss low-carbon concrete expectations, goals, procurement process, and responsibilities.
Set emissions targets for products and materials.
There are two main approaches for setting emission targets for products and materials:
Where possible, use industry average EPDs, CLF baselines, or an EC3 average to create a baseline and identify an achievable target for each material category based on available collections of EPDs.
Resources:
Embodied Carbon Toolkit for Building Owners (CLF)
Procurement Policies to Reduce Embodied Carbon (CLF)
EC3 - Embodied Carbon in Construction Calculator (Building Transparency)
Consider low-carbon structural systems and assemblies (e.g., mass timber, passive house, recycled or reused steel, or low-carbon concrete).
Mass timber can be an environmentally friendly choice when compared to traditional construction materials. Trees sequester carbon while they are growing and will continue to store carbon after they are harvested and turned into mass timber. The manufacturing process is also significantly less energy- and water-intensive compared to concrete and steel production.
WoodWorks
Passive house is a building design standard that promotes ultra-airtight building envelopes to maintain interior temperatures and save energy. Passive house helps reduce demand on heating and cooling systems, helping avoid refrigerants and materials for MEP systems, which generally have high global warming potential.
Passive House
Recycled steel (also known as secondary steel) is a preferred choice for reducing embodied carbon. The production of recycled steel in an electric arc furnace (EAF) requires less energy compared to the manufacturing process for primary steel. Currently, the most effective way to reduce embodied carbon from steel is to use less material overall.
Embodied Carbon of Steel (Arup)
Low-carbon concrete encompasses a broad range of innovations that aim to reduce the global warming potential of concrete mixes. These approaches might include material- or process-based solutions. Currently, the most effective way to reduce embodied carbon from concrete is to use less material overall.
The 3Cs of Innovation in Low Carbon Concrete (Rocky Mountain Institute)
Skanska Zero Emissions Construction Equipment Pilot Projects
Los Angeles, California, and Stockholm, Sweden
Quick Facts
Measuring and reducing emissions from construction site activities is a growing area of interest for owners and construction firms looking to achieve net zero. While estimates vary, these emissions can contribute up to 15 percent of a project’s total embodied carbon emissions.
Developer: LA Metro (Los Angeles), City of Stockholm Other partners: Volvo CE Project type: Transit expansion (Los Angeles), site prep for master-plan development (Stockholm) Status: In progress as of 2024
Tackling these emissions can be challenging due to the lack of data and standardized methodology for measuring and reporting. However, firms including Skanska and others are working to decarbonize their construction sites by piloting all-electric heavy machinery and using equipment powered by biofuels.
In Los Angeles, Skanska conducted a 90-day pilot program of a Volvo electric excavator on the Purple (D Line) Extension Transit project for LA Metro. Results of the pilot indicate that the excavator performed all required activities while reducing carbon per hour by 66 percent (34 kilograms) and saving fuel costs. Other benefits included reduced vibration and noise, providing a healthier and more comfortable environment for workers and the surrounding community. As one of the first use cases of zero-emission heavy machinery in North America, this pilot demonstrates the impact of low-carbon construction methods, particularly for large civil megaprojects such as the Purple Line extension. In Stockholm, Skanska is working with the city of Stockholm and Volvo CE to achieve a 100 percent fossil-free construction site at the Slakthusområdet E101 development, which will transform the city’s industrial meat-packing district into a new urban neighborhood. At the project’s halfway point, Volvo reported that 1,808 tons of C02 had already been avoided through the use of electric equipment and equipment powered with hydrotreated vegetable oil. Upon completion, Skanska anticipates that the project will save well over 2,000 tons of C02 emissions, which is equivalent to the emissions from 35 trucks driving eight hours a day for a year.
Consider low-carbon structural systems and assemblies (e.g., mass timber, passive house, recycled or reused steel, or low-carbon concrete).
Mass timber can be an environmentally friendly choice when compared to traditional construction materials. Trees sequester carbon while they are growing and will continue to store carbon after they are harvested and turned into mass timber. The manufacturing process is also significantly less energy- and water-intensive compared to concrete and steel production. To learn more about mass timber, visit: WoodWorks.
Passive house is a building design standard that promotes ultra-airtight building envelopes to maintain interior temperatures and save energy. Passive house helps reduce demand on heating and cooling systems, helping avoid refrigerants and materials for MEP systems, which generally have high global warming potential. To learn more about passive house, visit: Passive House.
Recycled steel (also known as secondary steel) is a preferred choice for reducing embodied carbon. The production of recycled steel in an electric arc furnace (EAF) requires less energy compared to the manufacturing process for primary steel. Currently, the most effective way to reduce embodied carbon from steel is to use less material overall. To learn more about embodied carbon reductions in steel, see: Arup Embodied Carbon of Steel (2020)
Low-carbon concrete encompasses a broad range of innovations that aim to reduce the global warming potential of concrete mixes. These approaches might include material- or process-based solutions. Currently, the most effective way to reduce embodied carbon from concrete is to use less material overall. To learn more about innovations in low-carbon concrete, visit: RMI The 3Cs of Innovation in Low Carbon Concrete (2023)
Pacific Center
Quick Facts
San Diego, California
Developers: Harrison Street and Sterling Bay Designer: Gensler Size: 800,000 square feet Project type: New construction Status: Under construction; first phase to be completed in 2025
Pacific Center is an 800,000-square-foot life sciences campus codeveloped by Harrison Street and Sterling Bay in San Diego’s Sorrento Mesa neighborhood. The first phase of the project, which broke ground in May 2023, will include 500,000 square feet of scientific research space, a 28,000-square-foot amenity center, and a parking facility. The inclusion of low-carbon materials including recycled content steel, low-carbon concrete mixes, and mass timber is helping the project achieve an 11 percent reduction in embodied carbon compared to the baseline. The programmatic requirements for the space, including the need to accommodate mechanical lab equipment, meant there was little flexibility to reduce embodied carbon through the building design. Despite these limitations, the project team conducted a whole building life cycle analysis to identify carbon-intensive areas of the project. During design development, the team leveraged the WBLCA results to inform the selection of systems and materials, opting to work with local material suppliers that could provide low-carbon concrete mixes and recycled steel. The project also incorporates low-carbon mass timber in the campus amenity pavilion, which will house exercise facilities and retail space. While extensive mass timber in lab and office areas was not feasible, mass timber made sense for the amenity pavilion and helped to reduce the campus’s embodied carbon by 607 metric tons of CO2. In addition to the project’s embodied carbon accomplishments, Pacific Center features an all-electric mechanical, engineering, and plumbing system powered by rooftop solar panels, significantly reducing the building’s operational carbon emissions. The campus’s remaining buildings will be built over several phases, with anticipated completion in 2028.
Encourage tenants to seek out low-carbon fit-out materials and consider embodied carbon implications of renovations.
Consider setting GWP limits for material and equipment replacements, when EPDs are available.
Avoid “white-boxing” spaces between tenants; encourage new tenants to retain existing fit-outs when possible.
See Fitting Out Spaces for Net Zero (Urban Land Institute)
See Low Embodied Carbon Tenant Fit-Out Guide (Hudson Pacific Properties)
Consider green leases and longer tenant leases to reduce turnover.
Taking Green Leases to Net Zero (ULI)
Track and minimize construction site carbon emissions.
Track construction equipment fuel consumption per activity and material scope.
See AGC Playbook on Decarbonization and Carbon Reporting in the Construction Industry
Identify and implement strategies to reduce equipment fuel emissions, such as using electrified equipment.
Create a summary sheet for reporting and tracking of transport emissions throughout the project’s completion.
Embodied Carbon Measurement and Accounting
Update the embodied carbon assessment for the as-built project to report actual embodied carbon.
Collect as-built material quantities and embodied carbon data for the materials included in the build.
Recalculate reductions using as-built information.
Identify the highest-impact portions of the project and immediately engage project team members with design influence over these “hotspots.”
While every project is different, studies have consistently shown structure, enclosure, and MEP systems are the leading elements for new buildings, and materials with the highest contributions are typically concrete and steel.
Encourage early consideration with the structural engineer specifically around low carbon goals, optimizing structural material and bay sizes, and the low carbon concrete process.
Seek out engineering firms that have signed on to low-carbon commitments, such as:
SE2050
MEP2040.
Engage the general contractor as early as possible. Once on board, require the contractor to connect with suppliers about embodied carbon reporting.
Create a list of suppliers and subcontractors you typically specify, procure, or purchase from.
Use an online tool—such as the Embodied Carbon in Construction Calculator (EC3)
—to determine if they have product-specific EPDs.
Set up meetings with suppliers who do not have product-specific EPDs to educate them on embodied carbon.
Send an official EPD request letter to suppliers to formalize ask and build a business case. See EPD Request Letter by Building Transparency.
How to Get an EPD (Building Transparency)
Analyze material durability and performance, including aesthetic longevity, to minimize replacement cycles.
NOTE: This analysis does not necessarily provide the full picture. If a product is less durable, but is lower in embodied carbon, bio-based, circular, has a take-back program, and/or is low-toxicity, it could be a better choice.
Portland International Airport Main Terminal Expansion
Quick Facts
Portland, Oregon
When complete in early 2026, the renovation and expansion of the main terminal at the Portland International Airport (PDX) will nearly double the airport’s annual capacity while achieving a 70 percent reduction in the overall structural embodied carbon footprint when compared to building an entirely new terminal. The project is characterized by its nine-acre mass timber roof made with wood sourced entirely from forests in Oregon and Washington. From the beginning, the project team, including the Port of Portland and design firm ZGF, envisioned the expansion as more than just a building upgrade. Instead, it became an opportunity to pay homage to the local environment and highlight the importance of sustainable materials and practices. The Port of Portland’s clear goals around sustainability informed these critical early decisions and helped avoid significant emissions from demolition and new material production. This commitment led the project team to reuse much of the airport’s existing infrastructure and integrate low-carbon mass timber into the design. A highlight of the project is the unique mass timber roof, which celebrates Oregon’s forests while also cutting embodied carbon. In comparison to traditional construction materials like steel and concrete, the production of mass timber emits lower greenhouse gas emissions, making it a sustainable choice for new construction. In addition, the project prioritized sourcing wood from landowners who were working to restore forest ecosystems, including small landowners, community forests, and sovereign tribal lands. By sourcing locally, the project saved transportation emissions while supporting regional economies. As a result of these commitments, around 2.5 million board feet (of the approximately 3.5 million board feet used for the roof) was sourced from forests certified by the Forest Stewardship Council (FSC) or landowners meeting the highest standards of sustainable forestry practices. This included 100 percent of the roof’s three- by six-foot lattice timbers and 95 percent of the glue-laminated mass timber (a type of mass timber product).
Developer: Port of PortlandDesigner: ZGF Other Partners: KPFF Consulting Engineers, Hoffman Skanska JV, Timberlab Size: Nine acres Project type: Renovation and expansion Status: Phase I complete; phase II anticipated completion in 2026
Kilroy Oyster Point - Phase 2
Quick Facts
South San Francisco, California
Developer: Kilroy Realty Designer: DGA Architects Other partners: Hathaway Dinwiddie Construction Company, Stok, Randall Lamb Associates, Magnusson Klemencic Associates, BKF Engineers, Clark Pacific Size: 865,000 square feet (Phase 2); 3,000,000 square feet (full campus) Project type: New construction Status: Under construction, anticipated completion Q4 2024
Kilroy Oyster Point is a three-million-square-foot life sciences campus located in the growing South San Francisco market. Phase 2 of the 50-acre waterfront campus broke ground in 2021 and includes 865,000 square feet of office, lab space, and amenities across three towers, two amenity buildings, and a garage. The project’s pursuit of LEED Gold certification for Phase 2 spurred a focus on embodied carbon. As part of the LEED certification requirements, Kilroy engaged decarbonization consulting company Stok to perform a cradle-to-grave assessment of the project’s structure and enclosure, with a goal to surpass the required 10 percent reduction threshold for the certification. To achieve this, the team focused solely on the materials being sourced for the project and used OneClick LCA software tool to quantify the carbon footprint of different materials and components. From there, the team incorporated carbon intensity performance targets into the material specifications and construction documents. The team primarily focused on the heaviest emitters of concrete, structural steel, and curtainwall glazing, and discovered that it was relatively easy to procure products that met Kilroy’s carbon requirements. Hathaway Dinwiddie Construction Company, the project’s general contractor, observed that requiring low-carbon materials did not impact cost. This was due in part to the Bay Area’s advanced knowledge and understanding of low-carbon concrete, which made it possible to find a ready-mix supplier that could easily provide mixes with lower embodied carbon than regional averages. One challenge the team encountered was a supply chain issue that resulted in the lightweight fill on deck mix for two buildings to be swapped out for an alternative mix that had 35 percent higher global warming potential. This substitution affected the overall WBLCA results by approximately 2 percent increase in embodied carbon; however, all buildings still surpassed the 10 percent reduction threshold required for the LEED certification. In total, Phase 2 achieved a 16-percent reduction across all four buildings, with each building ranging from 14.6 percent to 17.2 percent reductions.
Hang Lung Properties Gypsum Board Recycling Programs
Shanghai and Hangzhou, China
Quick Facts
Hang Lung Properties, which develops and manages diverse properties in Hong Kong and mainland China, is embracing circularity through a partnership with two leading gypsum board suppliers—Knauf and Saint-Gobain—and an innovation partner—TRASHAUS—to pilot the recycling of waste gypsum board in two projects. By standardizing recycling processes and improving data collection, these pilot projects aim to reduce the volume of construction and demolition waste going to landfills. The scrap and surplus gypsum board will be diverted from landfills and processed for use in other applications to support a circular economy. As of October 2024, Hang Lung, Knauf, and TRASHAUS have collected for recycling more than 1,500 pounds of Knauf’s waste gypsum board from a store fit-out renovation in Grand Gateway 66, Shanghai. Diverting these waste materials from landfill avoids the generation of hydrogen sulfide, a toxic gas, among other benefits. In addition, Hang Lung is working with Saint-Gobain on recycling gypsum scrap from the landlord area of their new construction project in Westlake 66, Hangzhou. Gypsum board (also known as plasterboard or drywall) is a common construction material used in walls, ceilings, and partitions, and can make up a third of a fit-out project’s new materials and up to 10 percent of all demolition waste by weight. While gypsum board recycling programs have been available for many years, most gypsum is disposed of in landfills due to challenges associated with diversion and contamination. When processed correctly, gypsum waste can be recycled and turned into a number of different products, including new gypsum boards, decorative plaster, and other materials. These efforts build upon Hang Lung’s goals for sustainable resource management, reduced carbon emissions, and less waste. The company has been monitoring the construction waste diversion rate and recycling rate at their development projects since 2022. In addition to continued monitoring, Hang Lung carried out an on-site waste study in 2024 to gain a deeper understanding of their construction waste recycling rate and practices.
Developer: Hang Lung Properties Other partners: LVMH, Knauf, Saint-Gobain, TRASHAUS Project type: New construction and tenant improvement Status: In progress as of 2024
Track and minimize transportation carbon emissions.
Create standard supplier bid language and reporting forms.
Track material manufacturing location, distance traveled to site, mode of transportation, and fuel type.
Create a summary sheet for reporting and tracking of transport emissions throughout the project’s completion.
Set emissions targets for products and materials.
There are two main approaches for setting emission targets for products and materials:
Where possible, use industry average EPDs, a baseline from the Carbon Leadership Forum (CLF), or an EC3 average to create a baseline and identify an achievable target for each material category based on available collections of EPDs.
Resources:
Embodied Carbon Toolkit for Building Owners (CLF)
Procurement Policies to Reduce Embodied Carbon (CLF)
EC3 - Embodied Carbon in Construction Calculator (Building Transparency)
Optimize design: Use less, reuse more, and design for disassembly.
Design for Disassembly
Use Less
As an industry, using less material overall is critical to carbon reduction efforts.
Designing for disassembly considers how a project's materials will be salvaged and reused after the building has reached the end of its useful life.
Buildings that Last: Design for Adaptability, Deconstruction, and Reuse (AIA)
Design for Disassembly in the Built Environment: A Guide to Closed-Loop Design and Building (King County)
Additional Resources
AIA-CLF Toolkit for Architects - Part III: Strategies for Reducing Embodied Carbon (AIA, CLF)
Reuse More
For sites and infrastructure, see Climate Positive Design Toolkit (Climate Positive Design)
See the Climate Positive Design Toolkit for sites and infrastructure.
Corporate Policies
Owners and developers should integrate embodied carbon into their corporate policies to send clear and consistent communication on priorities and emissions reductions. Corporate policies can take different forms, such as the following:
Company-wide sustainability commitments, such as net zero or supply chain (purchasing) emissions reduction targets and internal carbon pricing initiatives Embodied carbon can be integrated into company sustainability action plans, annual reporting documents, and other publications.
Company-wide green building policies and initiatives, such as certification requirements, design standards, or material selection requirements for new construction or tenant fit-outs that apply across a company’s portfolio Embodied carbon requirements can be integrated into project documents, such as requests for proposals, owner project requirements, contracts, and standard specifications.
Sustainable procurement policies, such as minimum sustainability requirements for suppliers
Resources
Corporate and Building Owner Commitments to Reduce Embodied Carbon (Carbon Leadership Forum)
Embodied Carbon Procurement Policies (Carbon Leadership Forum)
Track and minimize transportation carbon emissions.
Create standard supplier bid language and reporting forms.
Track material manufacturing location, distance traveled to site, mode of transportation, and fuel type.
Create a summary sheet for reporting and tracking of transport emissions throughout the project’s completion.
Define project-level embodied carbon targets and communicate them in the owner’s project requirements.
There are two primary approaches to setting project level targets (both require
WBLCAs):
NOTE: Baselines values are not widely available in North America.
Resources:
Embodied Carbon Toolkit for Building Owners (Carbon Leadership Forum)
Embodied Carbon Benchmark Study (Carbon Leadership Forum)
Science Based Targets Initiative
Key Terms
Abbreviations
Embodied carbon: According to the Carbon Leadership Forum, embodied carbon refers to the greenhouse gas emissions generated by the manufacturing, transportation, installation, maintenance, and disposal of construction materials used in buildings, roads, and other infrastructure. Environmental Product Declaration (EPD): EPDs disclose LCA results for specific products, providing information to consumers about the environmental impact of building products. They are frequently thought of as material “nutrition labels” that report on a variety of life-cycle impacts, including global warming potential, acidification, eutrophication, ozone depletion, and smog formation. Life cycle assessment (LCA): An LCA is an analysis that evaluates the environmental impacts of products and services, covering their life cycle from raw material extraction to waste treatment. Whole building LCA (WBLCA): WBLCAs measure the environmental impact of a whole building. However, it’s worth noting that currently, not all “whole” building LCAs include every component of a building in their scope. Many WBLCAs only include certain elements, such as structure and enclosure, and exclude other significant components such as mechanical, engineering, and plumbing systems and interiors.
EC3: Embodied Carbon in Construction Calculator EPD: Environmental Product Declaration ESG: environmental, social, and governance GHG: greenhouse gas GIA: gross internal area GWP: global warming potential LCA: life cycle assessment LEED: Leadership in Energy and Environmental Design MEP: mechanical, engineering, and plumbing TI: tenant improvement WBLCA: whole building life cycle assessment
Refine and finalize low-carbon specifications.
Some materials are prescriptively specified (e.g., gypsum wallboard) while others are specified in a performance-based manner (e.g., concrete). Final concrete mix selection is made at construction.
The Case for Performance Based Concrete Specs (CarbonCure)
Through consultation with the project team, commit to the most feasible strategies that result in lowest embodied carbon.
Ensure selected reduction strategies are reflected in the construction drawings and project manual.
Encourage longer replacement cycles of materials.
Consider the existing portfolio as a material bank.
If you are decommissioning or deconstructing spaces, assess whether materials may be used in other new builds or as replacements in current buildings. There are many services and organizations that support material reuse, such as the following:
Track and minimize product substitutions.
Review submittals and change orders to ensure compliance with low-carbon specification criteria.
Include requirements for tracking and reducing embodied carbon in requests for proposals (RFPs) and contract language for project partners.
Include requirements for managing embodied carbon, including completing embodied carbon assessments, collecting Environmental Product Declarations (EPDs), identifying reduction opportunities, and implementing strategies.
How to Get an EPD (Building Transparency)
Provide detailed information about low-carbon products in the building’s operations and maintenance manual.
Include information about circular products, products designed for disassembly, and any products that are eligible for manufacturer take-back programs.
Consider providing a full set of deconstruction documents.
Align team members around goals for low-carbon concrete.
Hold a preconstruction meeting with the general contractor, structural engineer, architect, sustainability consultant, and ready-mix supplier to discuss low-carbon concrete expectations, goals, procurement process, and responsibilities.
Align team members around goals for low-carbon concrete.
Hold a preconstruction meeting with the general contractor, structural engineer, architect, sustainability consultant, and ready-mix supplier to discuss low-carbon concrete expectations, goals, procurement process, and responsibilities.
Salesforce Benchmarking Study for Furniture and MEP Systems
Multiple locations
Salesforce is a sustainability-minded cloud-based software company with a large and growing global real estate portfolio. To better understand the full carbon footprint of the spaces it occupies, Salesforce partnered with Brightworks Sustainability and WAP Sustainability to measure the embodied carbon emissions from furniture and mechanical, engineering, and plumbing (MEP) systems in their projects. While the industry is advancing rapidly, embodied carbon data for furniture and MEP systems is lacking, and the categories are rarely included in most whole building life cycle assessments. To address this lack of data, Brightworks and WAP developed a methodology that could be followed to determine an embodied carbon factor for a wide range of products; those with Environmental Product Declarations (EPDs) and those without. The team then applied the methodology to a tenant improvement (TI) project that was representative of a typical Salesforce workplace. Using material data collected from each subcontractor on the project, the sustainability teams discovered that combined, MEP systems and furniture contributed about 68 percent of the project’s total embodied carbon emissions. The market for low-embodied-carbon furniture and MEP systems products is growing, but stronger demand signals from the development community are needed to push manufacturers to procure EPDs for their products. In the meantime, real estate stakeholders can seek out opportunities to reuse as many interior products as possible. A host of asset management tools, logistics companies, and other organizations are making it easier for owners and lessors to repair, refurbish, reuse interior products. These avenues are helping companies reduce their environmental impact and, in many cases, save costs from new product procurement.
Quick Facts
Developer: Salesforce Other partners: Brightworks Sustainability, WAP Sustainability Project type: Tenant improvements Status: Completed 2023
Embodied Carbon Measurement and Accounting
Refine the project’s embodied carbon estimate based on the building’s design and material selection.
Using materials and quantities specified by design, reconduct the embodied carbon assessment.
Useful tools at this stage include the following:
EC3 - Embodied Carbon in Construction Calculator (Building Transparency)
One Click LCA
tallyCAT
Track and minimize construction site carbon emissions.
Track construction equipment fuel consumption per activity and material scope.
See AGC Playbook on Decarbonization and Carbon Reporting in the Construction Industry
Identify and implement strategies to reduce equipment fuel emissions, such as using electrified equipment.
Create a summary sheet for reporting and tracking of transport emissions throughout the project’s completion.
Create low-carbon specifications that require EPDs for all components considered and tracked for embodied carbon reduction. Start with structural materials, such as concrete, steel, and wood at a minimum.
Include intentions for salvaged materials, circular materials, and materials with manufacturer take-back programs.
Reach out to suppliers to check on low-carbon product availability.
If selected products do not have an EPD, send an official EPD request letter to suppliers to formalize ask and build a business case.
Download an EPD Request Letter (Building Transparency)
How to Get an EPD (Building Transparency)
Encourage longer replacement cycles of materials.
Assess current standards and practices for determining material replacement during a building’s use phase.
Commit to replacement cycles based on material and product performance (versus a desired change in aesthetic) and include this in building standards.
The Gilbert
London, England
Quick Facts
At The Gilbert in London, Brookfield Properties transformed a historic building into a sustainable office space that honors the past while looking ahead to the future. A critical decision to retain 90 percent of the original structure helped the project achieve an 80 percent reduction in embodied carbon emissions when compared to demolishing and constructing a new building. The seven-story building, originally built in 1930 as a private members club by Sir Giles Gilbert Scott, now serves as the first Brookfield Properties building to achieve net zero in construction in line with the U.K. Green Building Council framework. To meet the requirements, the project team conducted a whole-life carbon assessment to understand the building’s impact. Sustainability consulting company Hilson Moran carried out the study during schematic design to evaluate the carbon intensity of different design options. The assessment revealed that significant carbon savings could be achieved by avoiding demolition and retaining the building’s structure, including the historic facade and architectural features. Specifically, the team opted to refurbish and reseal the original windows instead of replacing them, helping to save carbon while preserving one of the building’s most distinctive elements. Another modification included leaving the ceilings exposed to save carbon emissions from finishing materials. Brookfield Properties reported that these changes were essential for reducing embodied carbon as well as for saving substantial construction costs and shortening the development timeline. In total, the project’s embodied carbon emissions came in at 2,182 tons of carbon [based on 147 kg CO2e/m2 gross internal area (GIA)], beating the LETI Office Benchmark by 9,500 tons. Brookfield discovered that they could renovate the Gilbert seven times before it reached the same embodied carbon as one standard new office build of the same size (estimated at 1,000 kg CO2e/m2 GIA).
Developer: Brookfield Properties Designer: Stiff + Trevillion Other partners: Mace Size: 119,000 square feet Project type: Renovation Status: Completed 2021