We periodically field questions from architects and contractors about the percentage of recycled content and the U.S. Green Building Council's LEED rating of Unistrut materials.
The US Green Building Council’s Leadership in Energy and Environmental Design (LEED®) rating system has 6 categories each with a unique number of attainable credits. The maximum number of attainable LEED® credits is 69, while the minimum number of credits required to be LEED® certified is 26. The category “Materials & Resources” has two credit sections (Credit 4.1 and 4.2) for materials with recycled content each with an attainable credit of 1.
- Credit 4.1 - Recycled Content, 10% (post-consumer + ½ pre-consumer)
- Credit 4.2 - Recycled Content, 20% (post-consumer + ½ pre-consumer)
As a steel product, UNISTRUT® Metal Framing has a recycled steel content. However, the amount (percentage) of recycled steel depends on the steelmaking process used. There are two different steelmaking processes. These processes and the calculation for LEED® credit are discussed in the documents “2006 The Inherent Recycled Content of Today’s Steel” and “Steel Takes LEED® with Recycled Content – June 2006” as published by the Steel Recycling Institute (www.recycle-steel.org). The steelmaking processes are the Basic Oxygen Furnace (BOF) and Electric Arc Furnace (EAF). According to the Steel Recycling Institute, BOF uses 25% - 30% recycled steel, while EAF uses more than 80%. The table below provides more detailed information from 2006.
Based on this 2006 data, the Recycled Content % of UNISTRUT® Metal Framing for LEED® is:
Both of the Recycled Content % values exceed the 10% and 20% LEED® goals. Therefore, if UNISTRUT® Metal Framing was the only steel in the building, the LEED applicant would get a total of 2 credits (1 each for meeting the 10% and 20% goals) towards the 26 point minimum required for certification. Most likely there are other products in addition to UNISTRUT® in the building, so the LEED® applicant must consider all steel products in the building when evaluating for Credits 4.1 & 4.2.UNISTRUT® does not specify the steelmaking process when ordering steel. Therefore, when applying for LEED® credits, the applicant should use 25.3% Recycled Content for UNISTRUT® Metal Framing.