This afternoon I attended a specialty update system on the weighting system that is the underlying methodology behind the allocation of points in the upcoming 2012 LEED system. For those unaware, the USGBC is currently working to develop the next version of the LEED green building certification system, which is planned for release in 2012 and implementation in 2013. The public comment period for the 2nd draft of the LEED 2012 system closed recently. The Degenkolb Sustainability Committee conducted a review of the draft system and provided recommendations internally to help our engineers to provide feedback to the USGBC. There will be a 3rd draft & public comment period before the system is finalized, I encourage all interested parties to proved comments when that draft is released. The impacts that structural materials play in the current draft system are less (relatively to the total points available in the LEED system) than they are in the LEED 2009 system due to both the outcome of this points allocation process and additional considerations that have been wrapped into new areas and new points categories in the 2012 system. The presentation was more of a general overview of the points allocation process and did not address this issue directly but during a conversation that I had with one of the presenters (a high-level USGBC technical development representative) afterward I learned that according to the metrics used and assumptions made in the weighting system, the environmental impacts of materials in a building tend to be significant but not as significant as the impacts due to building operations throughout the building’s lifespan. A key dilemma in defining exactly what the impacts are due to building materials resides in the lack of sufficient LCA tools for industry to adequately measure those impacts. The USGBC representative noted this dilemma, the remedy of which is a key focus of the Carbon Leadership Forum (www.carbonleadershipforum.org
), a group out of the University of Washington that I’ve been participating in recently. This conversation highlighted an additional benefit of the work that CLF is doing: better representation and consideration of materials impacts in green building rating and certification systems.The final session I attended today was a group discussion that dove further into the challenges ahead that must be addressed to fully understand the environmental impacts associated with materials and products used in buildings. This discussion touched on challenges in developing consistent and reliable LCA methodology, Product Category Rules (PCRs) (an issue for structural materials that the SEAONC Sustainable Design Committee has addressed in their recent paper published in the 2011 SEAOC conference proceedings), and other forms of impact accounting and documentation. Many questions were posed in an effort to help frame the discussion moving forward toward solutions. The bottom line arrived at is that there are many differing perspectives and lots of debate on how we get to better understanding and reduction of material impacts (necessary and healthy debate I might add), but it is critically important to remember that representatives of all facets of the sustainable building industry are all working toward the same end goal of ensuring a healthy planet for future generations.Tomorrow is the closing day of Greenbuild 2011, check back for my final post.