EMBODIED CARBON IN GREEN RATING SYSTEMS

This credit requires the formation of an integrated design team, conducting an early design charrette, and early definition of LEED goals, including decarbonization of the project. Structural engineers can play a significant role in the integrative design process by providing early structural system evaluations and embodied carbon comparisons, and by actively participating in design charrettes to identify cross-disciplinary synergies. They should also help define measurable structural performance targets that align with project decarbonization goals.

This prerequisite requires quantifying the A1-A3 embodied carbon impacts of the structure, enclosure, and hardscape materials, identifying the top 3 sources of embodied carbon and the implementation of project-specific strategies to reduce those hotspots. If credit MRc2 is being pursued, the results of that credit satisfy the requirements of MRp2. The results of the MRp2 Assessment are used as input to the prerequisite IPp3 in assessing the overall carbon of the project. Structural engineers can contribute in the early design phase by performing embodied carbon assessments, comparing the material efficiency of different framing systems–such as optimizing grid spacing, reducing slab thickness through advanced analysis, or selecting composite framing systems–and exploring lower carbon material alternatives.  In addition, structural engineers can lower the embodied carbon of high-impact materials through implementation of structural optimization strategies, performance based specifications, coordination of GWP targets, procurement guidance, and collaboration with material suppliers. Refer to the SE2050 Embodied Carbon Estimator here, or see a list of tools for estimating embodied carbon here.

In LEED v4.1, this credit was Option 3 of the MR Building Life-Cycle Impact Reduction credit. It is now a stand-alone credit in LEED v5, with 1-3 points available for New Construction. Option 1 rewards projects that reuse structural and enclosure elements of existing buildings. Option 2 focuses on the material reuse, but structural materials are excluded. Building and material reuse is one of the most effective means of reducing embodied carbon. 

Option 1- Building Reuse

For New Construction projects, points are awarded by calculating the percentage of existing structure and enclosure reuse by the project area through Option 1. Reusing 20% of structure and enclosure earns one point, 35% reuse earns two points, and 50% reuse earns three points. Structural engineers can conduct a comprehensive structural evaluation of the existing building. This will help determine what can be safely re-used, what the structural capacity is of the existing structure, if the existing structure and foundation is adequate for new programmatic requirements, and if not, what upgrades are required.  

Option 2 – Materials Reuse

Structural engineers can support this credit by identifying opportunities to retain existing structural materials in place and incorporating salvaged materials from on- or off-site sources into the design—prioritizing high-impact materials like steel, timber, and concrete. Early coordination is critical to assess feasibility, verify structural performance and code compliance, and align design with material availability and salvage efforts. By reusing structural elements in existing buildings, the structural system’s overall embodied carbon footprint is reduced by avoiding carbon released during manufacturing and transporting new structural materials to the construction site. 

This credit tracks and reduces the embodied carbon of major structural, enclosure, and hardscape materials. 

Option 1: Whole Building Life-Cycle Assessment

Option 1 of MRc2 Reduce Embodied Carbon evolved from LEED v4, Option 4 of the MR Building Life-Cycle Impact Reduction credit. Option 1 of MRc2 Reduce Embodied Carbon has up to 6 points available for New Construction. This credit rewards a comprehensive cradle-to-grave (modules A-C, excluding operating energy and operating water-related energy) Whole Building Life Cycle Assessment (WBLCA) of the entire structural system, enclosure, and hardscape, and is compared to a baseline developed for the project. 

As part of the WBLCA, structural engineers can perform a Life Cycle Assessment (LCA) on the structural design to help identify areas of high environmental impacts, provide embodied carbon measurements, and develop the baseline building for comparison.. The baseline building must be of similar size, function, type of construction, and location as the proposed project. Refer to ASCE’s Whole Building Life Cycle Assessment: Reference Building Structure and Strategies for additional guidance.

New Construction projects can achieve 2 points if the LCA shows that the project embodied carbon meets baseline or industry average embodied carbon. If the project WBLCA demonstrates a reduction in global warming potential (GWP) of 10% compared to the baseline building, the project can obtain three points. Additional points are awarded as follows: a 20% GWP reduction earns four points (and is required for Platinum certification), a 30% reduction earns five points, and a 40% or greater reduction earns six points. 

Structural engineers can help reduce GWP compared to the baseline by:

• Identifying structural design modifications that will achieve required percentage reductions across impact categories; 
• Evaluating embodied carbon trade-offs between different structural systems; 
• Implementing design efficiencies; 
• Evaluating the use of high-strength materials; and
• Specifying low-GWP structural materials. 

Early in the design phase, the design team should agree on which consultant should include the WBLCA for the baseline building in their scope. For additional information on developing the baseline building for a WBLCA, see “Whole Building Life Cycle Assessment: Reference Building Structure and Strategies” published by the ASCE SEI Sustainability Committee, the SEI Prestandard for Assessing the Embodied Carbon of Structural Systems for Buildings  and the LEED v5 Building Design and Construction Guide.

Option 2: Environmental Product Declaration (EPD) Analysis 

This option expands upon LEED v4.1 MR Credit: Building Product Disclosure and Optimization – Environmental Product Declarations. The project team can earn points for using product or facility-specific EPDs to evaluate reductions in embodied carbon compared to industry-average values. EPDs are Type III environmental declarations that are third-party verified, based on an LCA and conducted according to established Product Category Rules (PCRs) per ISO 14025.

Path 1 is a project average approach, and Path 2 is a materials approach. Under this credit, structural engineers have the opportunity to help the project team achieve up to three LEED points in New Construction projects. Many structural materials have  product or facility-specific EPDs  which can be obtained from the material supplier or manufacturer.

• Path 1 earns points for reducing the embodied carbon of the entire project based on EPD data for applicable project materials compared to industry-average values. Projects must use project-specific material quantities and identify product-specific Type III EPDs to demonstrate reductions. For New Construction projects, one point is awarded for meeting the embodied carbon industry average, two points for a 20% reduction in GWP, and three points for 40% or greater GWP reduction. Core and Shell projects may earn four points if they reduce GWP by 50% or more. Refer to the Carbon Leadership Forum North American Material Baselines report for a comprehensive material based baseline.
• Path 2 earns points by demonstrating that structural, enclosure, and hardscape targeted material types have lower embodied carbon impacts than industry benchmarks. A weighted average approach within each material category can be used to calculate average embodied carbon intensity values. For New Construction projects, three material categories must be considered for one point and five or more material categories for two points. Core and Shell projects may earn up to three points.

Structural engineers can help with both pathways by specifying structural materials that have embodied carbon below industry average values as defined by the EPA, the CLF Materials Baselines report (or similarly “robust and widely recognized publications), and industry-average EPD applicable to the project region.

This credit requires the implementation of a construction and demolition (C&D) waste management plan, including tracking and reporting total waste and diversion rates. Points are earned by diverting materials from landfill through recycling, salvage, or take-back programs, with higher value placed on source-separated and salvaged materials.

While structural engineers are not responsible for tracking waste and diversion, they play a key role in reducing construction waste through design. This includes developing efficient structural systems that minimize material quantities and optimizing framing layouts to reduce offcuts. Early coordination with architects, contractors, and suppliers is critical to align grids, spans, and material selections with standard dimensions and fabrication practices.

Where feasible, engineers should pursue prefabrication and modular strategies to improve material efficiency and reduce on-site waste.

For this prerequisite, project teams must complete a climate and natural hazard assessment. Based on the identification of 2 priority hazards by the project team, structural engineers can bring essential expertise by identifying how these priority hazards impact structural systems and building performance, including load analysis for wind, flood, snow, flood and temperature extremes. Structural engineers can also identify weaknesses and failure modes of structures under projected climate scenarios and assess how changing environmental conditions will affect structural performance over the building’s intended lifetime. In addition, structural engineers can specify materials and connections that perform well under extreme conditions, design redundant systems to maintain structural integrity during potential partial failures, design flexible systems that can be upgraded over time, and select materials and systems that provide both resilience and low embodied carbon.

The Enhanced Resilient Site Design credit builds upon IPp1, Climate Resilience Assessment. It identifies best practices for at least 2 of the highest priorities hazards identified with the prerequisite.

• If the identified hazard is flooding, structural engineers can ensure that all structural materials, finish materials and connectors used below design flood elevation are flood resistant and designed to comply with ASCE 24-24 or the flood supplement to ASCE 7-2022.
• For hail, design the structure according to FORTIFIED Commercial Wind and Hail Supplement or local equivalent.
• For projects in hurricane-prone areas, structural engineers can design structures according to the FORTIFIED Commercial Wind standard and for projects in high wind areas or design to comply with ASCE/SEI 7-2016 or 7-2022 in specified Federal Emergency Management Agency (FEMA) zones or local equivalent.
• In areas of sea level rise, structural engineers can design with structural materials resistant to projected water damage levels.

United States Green Building Council (USGBC). (2025). LEED Building Design and Construction Guide, Version 5 Washington, DC. Accessed April 15, 2026. https://www.usgbc.org/leed/v5