LEED v4.1 BD+C – what’s new in the building LCA credit?
What’s new in LEED v4.1 BD+C for Whole-Building Life-Cycle Assessment
Changes to Whole-Building Life-Cycle Assessment in LEED v4.1
LEED v4.1 introduces several changes that make materials credits more accessible for projects. Restructured Materials and Resources (MR) credits in v4.1 ensure that the goals identified in LEED v4 are met. Moreover, for the first time in LEED, energy metrics include both cost and greenhouse gas emissions.
MR Credit: Building Life-Cycle Impact Reduction, Option 4. Whole Building Life Cycle Assessment
Summary of changes:
- Credit is more focused on carbon reduction; extra weight is given to the global warming potential
- Credit offers a point for completing whole-building LCA without demonstrating any reduction
- Credit points are tiered based on performance improvement, so you can get between 2 to 4 points depending on the reductions you achieve
The credit maintains the definitions of the constant parameters between baseline and proposed buildings and prevents an increase by more than 5% compared with the baseline building in any of the impact categories considered.
|Requirements for the path in LEED v4.1
|Conduct an LCA for the project’s structure and enclosure
|Conduct an LCA for structure and enclosure that demonstrates a minimum of 5% reduction in global warming potential and two other impact categories
|Conduct an LCA for structure and enclosure that demonstrates a minimum of 10% reduction in global warming potential and two other impact categories
|Incorporate building reuse and/or salvage materials into the project’s structure and enclosure for the proposed design. Demonstrate reductions compared with a baseline building of at least 20% for global warming potential and at least a 10% reduction in two other impact categories
The manual also clarifies the requirement for documentation, requiring a narrative of how the life cycle assessment was conducted and, if applicable, for paths 2, 3, and 4, what changes were made to proposed buildings in order to achieve the related impact reductions. The manual also clarifies the difference in characterization of fossil fuels between CML and TRACI.
In One Click LCA: All the LEED v4 compliant tools (TRACI-based for North America, CML-based for Europe and International) can be used as is also for LEED v4.1.