Total project values are weighted averages for each component calculated independently. Quantities are taken from
the bill of materials.
So, assuming the windows for a specific building are quantified on the general contractor’s Schedule of Values to cost
$500,000, and in this particular case, the pre- and postconsumer recycled content of each component fell near the
midpoint of the cited ranges, the LEED combined recycled
content would be calculated as 21. 3 percent.
Value of Recycled Content = ($500,000) ( 21.3%) =
$106,500. When added to recycled content values from other
building materials, this value possibly contributes to the 10
and 20 percent recycled content goals of the project seeking
Postconsumer Preconsumer
Recycled Recycled
Component Weight(lbs.) Content Content
Aluminum Extrusions 30,000 0 - 30 53 - 80
Aluminum Sheet 3,000 1 - 15 3 - 23
Glass 90,000 0 - 14 17 - 20
Elastomers 250 0 0
Hardware 1,500 0 - 25 35 - 80
Steel 5,000 23 - 59 7 - 33
LEED certification.
Note: Steel is the only product under LEED to also have a
default recycled content of 25 percent postconsumer, according to the Green Building Alliance.
Caveat: The USGBC and its certification affiliate, the Green
Building Certification Institute (GBCI), warn that it does not
certify materials alone, just people and buildings. The materials are evaluated in their applications and as a percentage
of purchase price.
The organization advises companies to do the following:
“Establish a project goal for recycled content materials, and
identify material suppliers that can achieve this goal. During construction, ensure that the specified recycled content
materials are installed. Consider a range of environmental,
economic, and performance attributes when selecting products and materials.
Editor Kate Bachman can be reached at kateb@greenmanufacturer.net.
American Institute of Steel Construction, www.aisc.org
American Iron and Steel Institute (AISI), www.steel.org
Steel Recycling Institute, www.recycle-steel.org
Wausau Window and Wall Systems Inc., www.wausauwindow.com
