Version 4 of the LEED rating system (LEED v4) was approved by the U.S. Green Building Council (USGBC) in June after a process that included six public comment periods. With previous versions, producers became familiar with reporting information related to regional-material distances and recycled content values. But with the new version, those metrics play a lesser role. New measures, such environmental product declarations (EPDs) and life-cycle assessment (LCA), are more important. Two Materials and Resources (MR) credits in LEED v4 could affect producers.
MRc1: Building life cycle impact reduction
This credit has four options. Three are related to reuse and up to five points are available. Option 1 gives points for historic building reuse. Option 2 gives points for renovating abandoned or blighted buildings. Option 3 gives points for using existing building elements, including structural elements, enclosure materials, and permanently installed interior elements (similar to previous versions of LEED).
Option 4 gives three points for conducting a whole-building life cycle assessment for new construction projects. This requires an LCA of the project’s structure and enclosure that demonstrates at least a 10% reduction in at least three of six impact categories, one of which must be global warming potential (see table), compared to a reference building. According to MRc1, “the reference and design buildings must be of comparable size, function, orientation, and operating energy performance as defined in EA Prerequisite Minimum Energy Performance.” The LCA also must conform to ISO 14044 and the minimum service life must be at least 60 years.
MRc2: Building product disclosure and optimization—environmental product declaration
Two options are available for achieving points in this credit: environmental product declaration and multi-attribute optimization. Option 1 requires using 20 permanently installed products, sourced from at least five different manufacturers, that:
- Have a product-specific declaration,
- Have an industry-wide (generic), Type III EPD,
- Have a product-specific Type III EPD, or
- Conform to a USGBC-approved program.
When performing calculations, products are valued based on the stringency of the declaration:
- Products with a product-specific declaration are valued at ¼ of a product;
- Products with an industry-wide (generic) EPD are valued at ½ of a product;
- Products with a product-specific Type III EPD are valued as a whole product.
For Option 2, 50% of the value of permanently installed products (by cost) must have extended producer responsibility or reduced environmental impact (per USGBC program). Extended producer responsibility means that products must be certified by a third party to show that the product’s impacts are below industry averages in at least three of the categories shown in the table.
Products that used to meet the criteria are also valued according to source location. Structure and enclosure materials cannot be more than 30% of the value of the compliant building products.
LEED v4 will have an 18-month roll-out period. Projects will still have the option to register under LEED 2009 until June 1, 2015. After that, project teams must use LEED v4. Until then, be prepared for inquiries related to environmental product declarations and concrete components as projects begin to ramp up adoption of the new system.