Page 61 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

42 Cha pte r T w o

Based on a CIR dated September 22, 2006 and included in LEED 2009, an exemplary
performance point can be earned over and above Option 1 for a project which meets
one of the two following requirements after all the requirements of Option 1 are met:

• The project itself must have a density of at least double that of the average
density within the calculated area [see Eq. (2.2.4)].
or
• The average density within an area twice as large as that for the base credit
2
achievement must be at least 120,000 ft /acre. [To double the area, use Eq. (2.2.3),
but double the property area first.]
Therefore, to obtain an EP point for SSc2 in addition to the point earned for Option 1,
one of the following two options must be valid. Either the inequality in Eq. (2.2.4) must
be achieved given the development density of the area as defined in Eq. (2.2.2)

DD = (GFA /A ) ≥ 2 = DD (2.2.4)
site P T area
or both Eqs. (2.2.5) and (2.2.6) must hold. These are based on the two additional variables
the development density of double the surrounding area (DDD ) as defined by the
area
density radius for double the area (DRD).
∑ GFA
DDDarea= i ≥ 120 000, ft /acre for all applicable buildings and
2
∑
lots within the DRD, including
AT
i
the subject project (2.2.5)
DRD = 3 × 2 × A T (2.2.6)

There are several additional definitions of the variables involved that must be
explained. The following definitions are per LEED-NC version 2.2 when noted in
quotation marks:
Project site area “For projects that are part of a larger property (such as a campus),
define the project area as that which is defined in the project’s scope. The project area
must be defined consistently throughout LEED documentation.” This will typically be
represented as A for most of the credit equations.
T
Density radius The density radius (DR) is determined by Eq. (2.2.3). A circle of a
radius equal to the density radius is then drawn on an area map with its center near the
center of the project site.
Density boundary This is the area within the circle as determined by drawing the
density radius. “For each property within the density boundary and for those properties
that intersect the density boundary, create a table with the building square footage
(GFAs) and site area of each property. Include all properties in the density calculations
except for undeveloped public areas such as parks and water bodies. Do not include
public roads and right-of-way areas.” Include the subject project, and include site areas
of vacant lots except as previously noted. These GFAs and site areas are used in the