855773644-LEED-v5-BD-C-Reference-Guide-Launch-Edition - Page 408

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make decisions to reduce the impacts a building’s materials will have on the environment by using a fully integrated and collaborative design process.

QUANTIFY EMBODIED CARBON IMPACTS

Quantifying the Embodied Carbon Impacts provides a holistic assessment of embodied carbon impacts across major material groups within the project’s structure, enclosure, and hardscape. Calculate the Global Warming Potential (GWP) for all materials within each sub-category. For example, within the structural system, the GWP of each type of concrete, steel, or other materials is individually assessed and then combined to determine the total GWP for the structure. Similarly, for the enclosure, materials like insulation, cladding, and glazing are evaluated, and components such as paving and landscaping materials are analyzed for the hardscape. By summing up the impacts of all sub-category materials, the project team can achieve a detailed understanding of the embodied carbon for each major group, enabling informed decisions to reduce the project’s overall environmental impact.

Teams must use building project documents, including construction drawings and specifications or software tools to group materials into a Bill of Materials (BOM) of structure, enclosure, and hardscape materials used on the project. The BOM must encompass all elements within the LEED project boundary, including any ancillary structures like attached or detached parking garages and other components with significant embodied carbon impacts. Quantities may come from as-built data or estimated quantities from the design phase.

QUANTIFY THE CRADLE-TO-GATE EMBODIED CARBON EMISSION

Quantifying the cradle-to-gate (A1–A3) embodied carbon emissions for each material focuses on emissions associated with raw material extraction (A1), transportation to the manufacturing site (A2), and the manufacturing processes (A3). Calculate the GWP based on the cradle-togate (A1-A3 stages) impacts for each applicable material used in the project. This involves multiplying the GWP/unit (from EPDs or default values) by the quantity of each material.

Teams will locate EPDs to determine the embodied carbon values for each material. If EPDs are unavailable, teams may use industry-standard defaults provided by regional data sources or integrated within qualifying software tools. Projects should follow a hierarchy of data:

• Use specific EPDs for the product, as published by the manufacturer. If a productspecific EPD is not available, use the U.S. Environmental Protection Agency (EPA) default values when available.

U.S. Green Building Council LEED v5 Reference Guide for Building Design and Construction, April 2025 Launch Edition 398