CIB W116—Smart and Sustainable Built Environments - Test Input

90% by using recovered materials. One exception is the eutrophication potential, which creates a
negligible impact, and for which only a modest reduction is indicated.
6. A nationwide potential
Modelling one house reveals the potential to reduce environmental burdens by using recovered
building materials. A total national benefit can be approximated by extrapolating these results to the
residential C&D debris generated in the U.S. annually.
The U.S. EPA (2009a) estimates approximately 270,000 residential units, or approximately 576
million square feet (52.7 million square meter) of residential facilities, were demolished in 2003. This
activity generated 19 million tons of debris. (17.25 million metric tons) of debris.
If 567 million square feet (52.7 million square meters) of new residential units were constructed using
methods and materials similar to the recovered materials model, annual benefits across the U.S. would
be:
• 163 billion megajoules of energy would not consumed.
• 33 million metric tons of natural resources would not extracted.
• 8 million metric tons of carbon dioxide equivalent would not emitted.
• 5 billion moles of H+ (positive hydrogen atoms) equivalent would not be released into water
sources.
• 58,000 metric tons of particulate matter hazardous to human health would not emitted to air.
• 10 metric tons of ozone-depleting substances would not be emitted to the atmosphere.
• 64,000 metric tons of NOx equivalent (smog potential) would not emitted to the atmosphere.
One may question whether this quantity of recovered materials could be absorbed into the residential
construction market. The number of residential units demolished represents roughly 30% of the new
housing market. The U.S. Census Bureau (2009) recorded 905,000 housing starts in the U.S. in 2008,
which represents an extremely slow period in the U.S. housing market. Roughly twice that number
was recorded over the more prosperous 2003-6 period. Therefore, there should be ample opportunity
to use all materials that can be recovered from obsolete housing units.
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