Next year, the dominant green rating system in the world will complete the transition to a new iteration: LEED version 4. This transition sends a strong signal to the materials industry: the definition of green materials in LEED is shifting from single attributes like "rapidly renewable" or recycled content percentages, towards considering a broad array of environmental attributes. This new framework values product transparency via disclosure of material ingredients, lifecycle impacts, and best practices for extraction of raw materials. LEED is one of many product eco-labels, building codes, and green rating systems that are adapting to better inform decisions based on systematic evaluation of a product's impact. Yet in this new era of transparency, recycled content can find itself somewhat in the dark.
The building industry's full range of impacts - including building product manufacturing, building site preparation, construction activity, and building occupancy and operations - account for about one-third of all raw materials used globally.  Recycling remains front and center as a key means to reduce these impacts on the natural systems that support life.
Thankfully, products manufactured from recycled feedstocks can fare very well in the age of transparency: raw materials extraction is reduced or avoided, and the life cycle impact of manufacturing products using recycled feedstocks compares favorably to virgin materials. However, contamination in the recycled source material can introduce impurities into resulting products. StopWaste and the San Francisco Department of Environment have partnered with experts at the Healthy Building Network (HBN) to document how the value, marketability, and safety of recycled content building products is enhanced through cleaner feedstocks, celebrate the benefits of recycled content, and to document opportunities for improvement.
Today we have released a report, Optimizing Recycling: Criteria for Comparing and Improving Recycled Feedstocks in Building Products, which explores and provides context for these ideas. In addition, we have released the first two in a series of in-depth analyses of opportunities and challenges in specific feedstocks, Post-Consumer Polyvinyl Chloride In Building Products, published in April, and Post-Consumer Cullet in California, published in September. A total of eleven feedstock evaluations are slated for release in the coming months, all available via our Optimize Recycling report page on healthybuilding.net.
In this new era of transparency, product designers, building owners, and consumers are forced to straddle two seemingly competing forces. First is the urgent need to make use of materials already in circulation. Second is to meet the demands of consumers as they look to minimize hazardous substances and exposure to problematic compounds in product supply chains. Our research effort with HBN provides specific recommendations that will lead to better understanding of the benefits of recycled content, the risks of certain feedstocks, and opportunities to make use of recovered materials by following industry best practices. It's not a compromise, it's optimization - and solutions are what the industry and our planet need.
This article was authored by both Wes Sullens and Barry Hooper. Wes Sullens is the Green Building Program Manager for the local government agency StopWaste in Alameda County, California. Barry Hooper is a Green Built Environment Manager for the City and County of San Francisco's Department of the Environment. Wes, Barry, and Melissa Coffin (Operations Manager of the Healthy Building Network) will present results of this collaboration at the Greenbuild Expo in Washington DC. Their session, Recycling in the Age of Product Transparency, will take place Thursday, November 19, at 4:30 p.m. (Session F11 in room 204).
 Estimates of this sector's raw materials usage varies between 24% and 40%. In Worldwatch Institute Paper 124, A Building Revolution: How Ecology and Health Concerns are Transforming Construction (1995), Lenssen and Roodman state that "40% of the world's materials and energy is used by buildings." (http://www.worldwatch.org/node/866). According to a 2011 estimate, "approximately 24% of global raw materials are consumed by the (building and construction) industry." Fernando Pacheco-Torgal, Luisa F. Cabeza, João Labrincha, Aldo Giuntini de Magalhaes, Eco-efficient Construction and Building Materials: Life Cycle Assessment (LCA), Eco-Labelling and Case Studies, Woodhead Publishing, Feb 14, 2014.
 Pacheca-Torgal et. al.