Life Cycle Assessment in LEED v4.1
Green Building Team on March 28, 2019
LEED v4.1 is here, and it’s ushering in a number of revisions that are likely to have an impact in developing the market. Some of those significant changes are to the MR credit Building Life-Cycle Impact Reduction, specifically Option 4. Whole-Building Life-Cycle assessment. Under LEED v4, project teams would earn three points for a Whole-Building Life-Cycle Assessment (WB-LCA) that demonstrated a minimum 10% reduction in three (of six) impact categories. These requirements remain unchanged in LEED v4.1 (they now comprise Path 3), however the structure of Option 4 is significantly different.
LEED v4.1 introduces new paths with respective point levels designed to incentivize development of WB-LCA studies. Each path represents a tier related to the performance of the LCA of the project. Path 1 is to simply perform an LCA, regardless of the results, and project teams will earn one point. For two points (Path 2), teams must demonstrate a minimum 5% reduction in three (of six) impact categories, one of which must be global warming potential. For three points (Path 3), the team must demonstrate a minimum 10% reduction in three (of six) impact categories, one of which must be global warming potential. And for a full four points (Path 4), teams must demonstrate a minimum 10% reduction in two (of six) impact categories, 20% reduction in global warming potential, and incorporate building reuse and/or salvaged materials into the project structure and enclosure. Additionally, for Path 2, 3 and 4, no single impact category may increase by more than 5% compared with the baseline building. As with LEED v4, the requirements in LEED v4.1 to have a baseline and proposed building of comparable size, function, orientation and operating energy performance remains unchanged. Similarly, the service life of the building must be 60 years.
One of the goals of LEED v4.1 revisions is to have the credit requirements be more broadly achievable, which is apparent with the range of paths introduced with Option 4. We expect these changes will increase the accessibility of, and interest in, using whole-building life-cycle assessment to improve the design of upcoming LEED projects. Given LEED v4.1 is a Beta rating system, to help accelerate and deepen market transformation, we encourage project teams to explore LEED v4.1 and provide feedback prior to the final balloted requirements. For more information on how to have your say, see below.