By Claude Goguen, P.E., LEED AP
For thousands of years, humans have manipulated the natural environment to better suit their needs. One of the results is a construction industry which has become the largest consumer of renewable and non-renewable natural resources. It relies heavily on the natural environment for supplying raw materials such as timber and aggregates. Globally, buildings use 40% of raw materials and almost 14% of all potable water (1).
With this much demand on our natural resources, owners want more transparency in what materials are used to construct buildings. It’s been a challenge for specifiers and designers to choose the right materials based on inconsistent and conflicting information, but the need for a standardized format of reporting relevant life cycle data has been met with the advent of the environmental product declaration (EPD).
What is an EPD?
An EPD provides quantifiable environmental data used to compare products that fulfill the same function. It’s like a nutrition label on boxes of cereal, which contains information such as calories, fat and sugar. Thanks to the labels, a consumer can make an informed decision on which cereal to choose. EPD indicators include acidification potential, primary fossil energy consumption and net fresh water. The detailed analysis that goes into making an EPD considers all processes in the manufacture of a product, including raw material and energy extraction, preliminary production and the manufacture of end products.
International Organization of Standards defines three types of EPDs:
- Type I – Eco-Label
- Type II – Self-Declaration
- Type III – Environmental Declaration
The type depends on the degree of third-party verification and endorsement.
Considerable work goes into creating an EPD. Initially, large groups such as the precast industry collaborate to develop a product category rule (PCR). This provides instructions on how to conduct a life cycle analysis (LCA) and the subsequent EPD.
Three precast industry groups – National Precast Concrete Association, Precast/Prestressed Concrete Institute and Canadian Precast/Prestressed Concrete Institute – developed the PCR and LCA in recent years. With the help of data from nearly 100 plants throughout North America, the EPDs were written and published in late 2015.
The industry-wide EPDs are available for architectural and insulated wall panels as well as structural and underground precast concrete products. The wall panel EPD addresses conventional and sandwich wall panels and architectural trim products. The structural EPD covers bridge products, building products, retaining walls and sound walls. Structural precast products can be conventionally reinforced or prestressed. The underground products EPD covers pipe, culverts, manholes, wastewater and stormwater tanks, chambers and related products such as electrical utility products. These documents provide architects, engineers, building owners and other project stakeholders insight on precast concrete’s environmental impacts across a wide range of end uses.
EPDs and the green building movement
Leadership in Energy and Environmental Design v4, the Architecture 2030 Challenge for Products and the International Green Construction Code either request EPDs or reward building product manufacturers for submitting them. LEED v4, which will replace the older version of LEED in October, provides two points for a project with 20 products with EPDs and 50% of products demonstrating lower impacts than industry baselines through EPDs. LEED v4 values different types of EPDs as follows:
- Self-declared EPDs (Type II) are worth 1/4 value (not third-party verified)
- Industry-average EPDs (Type III) are worth 1/2 value (third-party verified)
- Product-specific EPDs (Type III) are worth full value (third-party verified)
What does this mean for designers and specifiers?
The green construction industry is constantly growing. While it used to be confined primarily to California and the Northwest, it’s now spreading across the country. Last year, a customer even asked an NPCA member in Georgia for an EPD on a grease interceptor.
EPDs are a great tool for architects and designers looking to maximize sustainability while creating and building the best possible projects that earn industry certifications and LEED credits. Use them to your advantage as you consider your next building, bridge, sewer or road design. Familiarize yourself with these tools to make your material selection process simpler and your completed work more successful.
Copies of the EPDs referenced here can be downloaded for free at precast.org/epds.
For questions or comments, please contact Claude Goguen, director of sustainability and technical education, at [email protected] or (800) 366-7731.
Claude Goguen, P.E., LEED AP, is NPCA’s director of sustainability and technical education.
(1) Lenssen and Roodman (1995). Worldwatch Paper 124: A Building Revolution: How Ecology and Health Concerns are Transforming Construction. Worldwatch Institute.