As the US Green Building Council finished its annual Greenbuild Conference in Washington, DC, last week, one somewhat unlikely organization came away touting better opportunities for its green and sustainable products: The Steel Market Development Institute.
Steel, you say? Doesn’t it burn a lot of fossil fuels just to get the iron ore out of the ground? Isn’t the process to turn it into structural beams and bars energy-intensive and dirty, as well? Perhaps, if you’re looking at mined and milled steel only, but if you look at less-obvious concepts like reusability, material reduction through smart design, recyclability, decreased maintenance cost and empowerment of adaptive reuse, steel and, even some other metals, are ahead of the game when it comes to construction specification.
The USGBC introduced will put its latest sustainable building certification, Leadership in Energy and Environmental Design version 4 (LEEDv4), into effect early next year. It approaches building materials content credits in a completely different way than previous editions of LEED.
“The new version of LEED, the primary changes are in the materials section and those changes are mostly around things like lifecycle assessment, environmental product declarations, transparency really,” said Mark Thimons, vice president sustainability at the SMDI. “What’s it take to make this product? What’s in it?”
Steel is North America’s number one recycled material. The US Geological Survey estimates that 72 million metric tons of ferrous scrap were purchased in 2012.
Thanks to electric arc furnaces being adopted as the default production process of major producers such as Nucor Corp., and the high US rate of scrap recycling, steel has a chance to do something many building materials cannot: show a consistent and transparent recycled supply chain.
What were once 8 materials and resources (MR) credits for LEED-certified buildings projects — for materials reuse, recycled content, regional materials, rapidly renewable materials, and certified wood — are now 6 credits (8 for the healthcare version of LEED). There are new information submittals and higher thresholds. The credits are:
- MR Credit: Building Product Disclosure and Optimization – Environmental Product Declarations
- MR Credit: Building Product Disclosure and Optimization – Sourcing of Raw Materials
- MR Credit: Building Product Disclosure and Optimization – Material Ingredients
- MR Credit: Furniture and Medical Furnishings (healthcare only)
All of these credits have at least one option that involves knowing the total cost of permanently installed products, collecting detailed information on all of those products, and calculating what percentage meets the criteria for the credit.
The minimum percentage is high — 25-50%. In addition, the criteria involve documentation that we in metals are all too familiar with, that is not widely available for other products: Environmental Product Declarations (EPDs).
“Steel construction products either already have these environmental product declarations or people will soon be producing them,” Thimons said. “When it comes to whole-building lifecycle assessment, our organization has the data available to allow architects and engineers to do those assessments. These requirements and prerequisites really require a different way of looking at building projects.”
Each of the MR Credits offers two paths, one relatively easy, the other potentially impossible. The first is referred to as “Disclosure.” The essence of disclosure is to use some products that have available the specified documentation, regardless of what the documentation says about the product. For instance, disclosure for the EPD credit involves using at least 20 different products for which environmental product declarations are available, from at least 5 different manufacturers.
In theory, a team of architects and specifying engineers could accomplish this through research and specifying proprietary products. The only criterion is whether the product has an EPD. It could still meet the disclosure criteria without being arbitrarily considered “green” as some products were under previous versions of LEED. The other MR credits have similar low-threshold options.
Optimized Building Projects
The second option is “optimization.” The essence of optimization is to use a certain percentage of products that comply with specific characteristics demonstrated by the disclosure option documentation. For EPDs, the optimization option requires that 50% of all installed products demonstrate environmental impact below industry averages for 3 out of 5 impacts that would be documented in an EPD, such as global warming potential.
Achievement of that option would first require that 50% had EPDs or equivalent documentation, then that they meet the criteria. The other MR credits have similar high-threshold options.
“Sourcing of raw materials” covers certified wood, recycled content (such as steel), bio-based content, and reused materials, and gives extra “credit” for local sourcing within 100 miles of the project. “Material Ingredients” covers content that could adversely affect human health, with various types of documentation never before considered by LEED.
Steel Gets a Leg Up
This is where steel, and other recycled metals, are in an enviable position compared to other building materials, a position they did not enjoy in previous versions of LEED.
“Wood has (in the previous versions of LEED) been getting a lot of traction from being a sustainable material,” Thimons said, “but we’ve said all along that it’s a shortsighted view. There are end of life issues. What happens if it gets burnt or put in a landfill? You’re probably aware of the war that’s been going on between the various wood certifications and, LEED, right now only accepts one.
Steel has virtually no VOCs and the recycled content credit can come from the steel of a building. It’s also possible to trace steel products origins, whether recycled or not, even if they don’t have EPDs as most already do. The supply chains of products such as rebar and curtainwall are an open book compared to products made of wood or plastics.
Who Will Record This Data?
It will be interesting to see how architects, engineers and construction professionals pursue the new transparency credits. Considering that the optimization thresholds are so high and the documentation for so many building products is not widely available, it probably is not possible at present to specify that the general contractor is to provide only products that meet the criteria for projects attempting LEED certification.
For instance, giving a GC a “goal” (requirement) to provide a minimum of 25% recycled content, even in combination with other types of content, could conceivably create an impossible specification requirement. Even if you do the research, find products, and estimate quantities and costs, you’ll still need data on the actual products used — information only the GC can collect. Products with available data, such as that from SDMI, can help a GC put into the situation of being data collector.