855773520-LEED-v5-ID-C-Reference-Guide-Launch-Edition-1 - Page 252

Extracted Content

Quantify Embodied Carbon Impacts

Quantifying the embodied carbon impacts provides a holistic assessment across major material groups within the project: interior materials (i.e., gypsum wallboard, flooring, insulation, wood and wood composites, wall framing, ceiling systems, concrete, metals, paints, and coatings). Project teams may include furniture at their discretion. The GWP is calculated for quantities of all major materials within the project scope of work. By summing up the impacts of all materials, the project team can achieve a detailed understanding of the embodied carbon for each product 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 interior materials and furniture used on the project. The BOM must encompass all substantial elements within the LEED project boundary. As a minimum requirement, the BOM should cover materials such as gypsum wallboard, flooring, insulation, wood and wood composites, wall framing, ceiling systems, concrete, metals, paints, and coatings. Project teams may include furniture at their discretion. 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) 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: first, use specific EPDs for the product, as published by the manufacturer. If a product-specific EPD is not available, use the U.S. Environmental Protection Agency (U.S. EPA) default values when available. Next, refer to the most recent Carbon Leadership Forum (CLF) Material Baselines report. [65] Then, consult other credible and widely recognized publications, including industrywide EPDs relevant to the project region.

65 “Carbon Leadership Forum Material Baselines for North America / August 2023”, Carbon Leadership Forum, (2023), accessed March 31, 2025, https://www.carbonleadershipforum.org/clf-material-baselines-2023/.

U.S. Green Building Council LEED v5 Reference Guide for Interior Design and Construction, April 2025 Launch Edition 241