Getting Ready for LEED v4: Part 1
ISOs, LCA, PCRs, & EPDs
By Meagan Young

The latest version of the U.S. Green Building Council’s (USGBC) LEED certification program rolls out this year – LEED v4. At the end of October, USGBC will require projects to register under LEED v4, which features new credits in building product disclosure.  One credit in particular, the Materials and Resources Credit: Building Product Disclosure and Optimization – Environmental Product Declarations, encourages teams to “[select] products from manufacturers who have verified improved environmental life-cycle impacts.”1

If you have tried to venture into the world of product disclosures, you know it’s fraught with acronyms and dense reading. Here is a quick overview of what you need to know to be more informed about material selection as it pertains to sustainable structural design and the new LEED v4 credits.

We’ll start at the top: the International Organization for Standardization (ISO) created the ISO 14000 series, the applications of which range from environmental aspects of product design to tabulation of greenhouse gases.2 Several of these ISOs define the process of life cycle analysis (LCA), which is a method by which individuals can evaluate the environmental impact of a building over its lifetime.  This timeframe is typically referred to as “cradle-to-grave.”

Once an LCA is performed, the results need to be presented in an accessible way. The rules that govern how to bound, calculate, and present this data are laid out in a Product Category Rule (PCR), which is authored by industry experts on a particular material. The PCRs used for common structural materials in the United States (or North America in general) were drafted by the Carbon Leadership Forum (concrete), FPInnovations (timber), and SCS Global Services (structural steel).

This leads us to the document of most use to structural engineers: an Environmental Product Declaration (EPD). The primary purpose of an EPD is to provide a narrative of a product’s environmental impacts from its initial extraction to the end of its functional life (cradle-to-grave). EPDs are meant to be comparable for products of similar material (e.g. comparing two different timber product options), but it is important to note that they do not suggest whether one product is “superior” to another. EPDs simply present the results of an LCA, nothing more and nothing less.

Due to differences in authorship and boundary conditions of PCRs, EPDs are currently unable to be compared between products of different materials. Efforts are under way to address this inconsistency. Additional tools are available to engineers for conducting an LCA, including the Tally module for Revit, GaBi LCA databases, or the Quartz Project open database of health and environmental impacts of building products.

The important thing to note for achieving the LEED v4 credit is that, under one option, you simply have to use 20 permanent materials that have some sort of EPD or declaration from a USGBC-approved program. There are no performance thresholds which have to be met; the materials and products claimed for the credit just have to report their environmental impacts in an approved format. That being said, it is now possible and encouraged for structural engineers to use EPDs to better inform their product selection and reduce their project’s environmental impact.

Environmental disclosures are just one of many updates in the latest version of LEED, and hopefully this provides you with a basic understanding of the process and acronyms involved with this documentation.  Stay tuned for Part 2 in an upcoming newsletter, which will feature a more in-depth discussion on key updates and differences between LEED 2009 and LEED v4.

Acronyms

USGBC: U.S. Green Building Council
LCA: Life Cycle Analysis
ISO: International Organization for Standardization
PCR: Product Category Rule
EPD: Environmental Product Declaration

References

1U.S. Green Building Council (USGBC). 2013. LEED Reference Guide for Building Design and Construction. 2013 Ed., Washington, D.C.: USGBC.

2International Organization for Standardization.  2009. “Environmental management: The ISO 14000 family of International Standards.” Accessed via web. http://www.iso.org/iso/iso14000

Meagan Young (myoung@mka.com) is a member of the SEAW Sustainability Committee and a Design Engineer at Magnusson Klemencic Associates. For more information about the committee, contact Kyle Steuck (ksteuck@degenkolb.com).