Section 1: Twelve LEED Rating Scenarios
the targeted rating level. These higher cost
to be more clearly identified. A few isolated
credits were generally selected based on the
exceptions to the methodology occur when
added value they could bring to a project (e.g.,
synergistic credits are involved.
lower operating costs, improved indoor
Supporting Information
environmental quality). Synergistic cost
impacts were also a factor in moderate to high
Cost estimate summaries for each of the twelve
cost credit selections.
scenarios are included in Appendices A and B of
this report.
2) "Bracket" the Costs
The individual credit evaluations and costs are
In the Courthouse model, one "low cost" and
included in Section Two and Appendices C and D
one "high cost" scenario was defined at each
of this report.
rating level in order to bracket the potential
LEED costs. The low cost scenarios include a
The synergistic credit evaluations and costs are
number of no-cost credits that may not be
included in Section Three and Appendices E and F
attainable (or achievable at no cost) in all GSA
of this report.
projects. Examples of these "conditional" no-
cost credits include Site Selection (SS-1),
Development Density (SS-3), Reduced Site
Disturbance (SS-4), Water Efficient
Landscaping (WE-1), Recycled Content
Materials (MR-4), and Regional Materials (MR-
5). In the high cost scenarios, most of the
conditional no cost credits are excluded. The
high cost scenarios are therefore forced to
include additional credits with moderate or
high cost premiums.
In the Office Building model, a "minimal
faade renovation" and a "full faade
renovation" scenario was defined at each
rating level. The different faade renovations
reflect one of the most significant scope
variations in GSA's modernization projects; as
such, they were used as the basis for
bracketing the potential LEED Office
Building costs. The differences in the faade
renovations affect a number of credits in the
Energy and Atmosphere, Materials and
Resources, and Indoor Environmental Quality
sections of LEED.
3) Use an Additive Approach to Achieve Higher
Rating Levels
In both the Courthouse and Office Building
models, the higher rating levels were "built-
up" from the lower rating scenarios. For
example, Silver ratings were developed by
using the same credits included in the Certified
rating scenarios, plus seven additional credits.
Gold ratings were then built-up from the
Silver ratings. This methodology allows the
cost changes from one rating level to the next
GSA LEED COST STUDY
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