Page 46 - Green Building Through Integrated Design

24 GREEN BUILDINGS TODAY

The LEED Rating Systems

LEED rates all buildings across five major categories of concern, using key environ-
mental attributes in each category. LEED collects and incorporates a wide variety of
“best practices” across many disciplines including architecture, engineering, interior
design, landscape architecture, and construction. It is a mixture of performance stan-
dards (e.g., save 20 percent of the energy use of a typical building) and prescriptive
standards (e.g., use paints with less than 50 grams per liter of volatile organic com-
pounds), but leans more toward the performance approach. In other words, LEED
believes that best practices are better shown by measuring results (outcomes) not by
prescribing efforts alone (inputs).
Each LEED rating system (see Table 2.5) has a different number of total points, so
scores can only be compared within each system; however, the method for rewarding
achievement is identical, so that a LEED Gold project for New Construction repre-
sents in some way the same level of achievement (and degree of difficulty) as a LEED
Gold project for Commercial Interiors (tenant improvements). Figure 2.3 shows how
the LEED-NC rating system splits points into the five major categories of concern.

TABLE 2.5 THE FOUR MAJOR LEED RATING SYSTEMS FOR LARGE
BUILDINGS, SPRING 2008
PERCENTAGE PERCENTAGE
OF TOTAL OF TOTAL
RATING SYSTEM TYPE OF PROJECT REGISTRATIONS* CERTIFICATIONS
LEED for New New buildings and 66.0 74.0
Construction major renovations;
(LEED-NC) housing more than
four stories
LEED for Tenant improvements 10.3 16.3
Commercial and remodels that do
Interiors not involve building
(LEED-CI) shell and structure
LEED for Buildings in which 13.7 4.5
Core and the developer or
Shell owner controls less
(LEED-CS) than 50% of tenant
improvements
LEED for Existing Ongoing building 10.0 5.2
Buildings operations, including
(LEED-EB) purchasing policies
*Data for LEED registrations and certifications are from the USGBC, furnished to the author, end
of March 2008.