Comment period opens on standards for measuring environmental footprint of concrete

Sources: Carbon Leadership Forum, University of Washington College of Built Environment, Seattle; CP staff

By Don Marsh

The Carbon Leadership Forum is seeking input on “Product Category Rules (PCR) for ISO 14025 Type III Environmental Product Declarations (EPD) for Concrete” from concrete producers and their suppliers, architects, engineers, life-cycle assessment and environmental specialists.

Posted at the CLF PCR Website, with comment period through March 31, the draft presents guidelines for producers to report the ‘environmental footprint’ of different mixes, thereby enabling design professionals to specify low impact concrete. The document details energy or fuel consumption inputs and related environmental impacts (i.e. global warming potential/carbon footprints) producers need to account for and report in an EPD. This PCR addresses impacts of making concrete from the ‘cradle to gate’, and thus includes raw materials extraction, production and transportation; it can be used for both ready mixed and precast concrete. Requirements for such documentation could be commonplace as green building practitioners and their clients look past LEED certification in favor performance-based project measurements.

A 14-member Carbon Leadership Forum committee began work on “PCR/EPD for Concrete” in January 2011. Industry representatives are Jeff Davis of Central Concrete Supply, San Jose, and Greg McKinnon of Stoneway Concrete, Seattle; plus National Ready Mixed Concrete Association’s Lionel Lemay, Precast/Prestressed Concrete Institute’s Dean Frank, and Massachusetts Institute of Technology/Concrete Sustainability Hub’s John Ochsendorf.

PCR and EPD prepared according to consensus guidelines—and (International Organization for Standardization) ISO 14025-2006—are aimed at helping architects and engineers meet the 2030 Challenge for Products. With phased targets over nearly two decades, it compels building industry suppliers to reduce the carbon-equivalent footprint of their materials and products at least 50 percent against current industry benchmarks. The Challenge was issued by the American Institute of Architects-aligned Architecture 2030, a non-profit group focused on addressing climate change by lowering energy consumption throughout the building sector.

PCR and EPD are intended to fill data voids design professionals encounter when trying to quantify environmental impacts of concrete and other materials or products, according to the Carbon Leadership Forum. Design professionals, the group adds, “try to compare the environmental performance of similar products and to date they have not been able to find a way to make apples-to-apples comparison. To advance a more comprehensive understanding of the total life cycle environmental impacts of buildings, design professionals need objective and verifiable environmental impact data … An EPD reports the results of life cycle assessment analyses (e.g. global warming potential, water use etc) in a consistent manner following agreed upon rules.”