Page 243 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

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International Organization of Standards document, ISO 14021—Environmental labels and
declarations—Self-declared environmental claims (Type II environmental labeling). Post-consumer
material is defined as waste material generated by households or by commercial, industrial
and institutional facilities in their role as end-users of the product, which can no longer be
used for its intended purpose. Pre-consumer material is defined as material diverted from
the waste stream during the manufacturing process. Excluded is reutilization of materials
such as rework, regrind or scrap generated in a process and capable of being reclaimed
within the same process that generated it. (As noted in Table 5.0.0, LEED 2.2 has a now
modified MRc4.2 credit for accomplishing a 20% recycle rate.)
Potential Technologies and Strategies
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.

Calculations and Considerations (LEED 2009 MRc4)
The intention of these credits is to use items that are made from materials which have
been made from recycled materials to reduce the use and costs (economic, social, and
environmental) of using virgin material sources. In this case recycled differs from salvaged
in the sense that the salvaged items as addressed in the materials reuse subcategory
(MRc3) are recycled in their final functional form and recycled items in the recycled
content subcategory (MRc4) are made in part from materials recycled either after final use
(postconsumer) or from by-products of industrial processes (preconsumer). Materials
that are preconsumer but that could be put back into the industrial stream from whence
they came are not eligible. There is greater value given for the items recycled postconsumer,
since they have already gone through two types of material streams: manufacturing and
final product use.
As in many of the MR credit subcategories, these credits are based on material cost
and values. There are so many different types of materials and material assemblies
(items) installed in the built environment, and cost (or value) is really the only common
element that can be used for comparison in typical construction analyses. The credit
criteria are based on the percentage of total material costs that come from preconsumer
and postconsumer recycled materials. The values of the preconsumer and postconsumer
recycled portions of the materials can be defined as follows:

MATL$ Total value of postconsumer recycled portion of materials (CSI 3
RECPOC
through 10, 31.60, 32.10, 32.30, and 32.90) plus any value of
postconsumer recycled portions of furniture or furnishings if included
consistently in MR subcategories 3 through 7. Value determinations
are based on postconsumer recycled weight percent of the value of
each of the individual items.
MATL$ Total value of pre-consumer recycled portion of materials (CSI 3
RECPRC
through 10, 31.60, 32.10, 32.30, and 32.90) plus any value of
preconsumer recycled portions of furniture or furnishings if included
consistently in MR subcategories 3 through 7. Value determinations
are based on preconsumer recycled weight percent of the value of
each of the individual items.
MATL$ See definition under MRc3.
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