Page 113 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

94 Cha pte r T w o

Exterior Lighting Part 2: This requirement is in addition to one of the interior lighting
requirement options and the exterior lighting requirement part 1, previously described.
It is intended to limit the lighting distribution beyond the site, both horizontally and
vertically. Since different uses have different lighting needs, the project site will have
different light distribution requirements according to where it is and how it is used.
There are four applicable groupings, and they are referred to as the outdoor lighting zones
as given in IESNA RP-33 and as defined by the International Dark-Sky Association
(IDA) and are given in Table 2.8.2.
The IDA is the International Dark-Sky Association and can be found at www.darksky.org.
The Illuminating Engineering Society of North America (IESNA) Recommended Practice
Manual: Lighting for Exterior Environments (RP-33) is the referenced standard for the
definition of the lighting zones. LEED-NC 2.1 gives the 1999 version as the standard, while
LEED-NC 2.2 does not reference the updated year. However, the LEED-NC 2.2 and
2009 Reference Guides specifically define the four lighting zones and the definitions as
so described from the IDA website are given in Table 2.8.2. Note that Table 2.8.2 also
gives examples for very dark lighting zones. These are not really applicable to new
construction as they represent undeveloped or specially developed (observatory) areas
only. Figure 2.8.1 is a photo of exterior lighting with shielding along the beach in Ft.
Lauderdale which reduces light escape beyond the site.

Zone Ambient Illumination Typical Examples
LZ0 Very dark “Critical dark environments, such as especially
sensitive wildlife preserves, parks, and major
astronomical observatories”
LZ1 Dark “Developed areas in state and national parks, recreation
areas, wetlands and wildlife preserves; developed
areas in natural settings; areas near astronomical
observatories; sensitive night environments; zoos;
areas where residents have expressed the desire to
conserve natural illumination levels”
LZ2 Low “Rural areas, low-density urban neighborhoods and
districts, residential historic districts. This zone is
intended to be the default condition if a zone has not
been established.”
LZ3 Medium “Medium to high-density urban neighborhoods and
districts, shopping and commercial districts, industrial
parks and districts. This zone is intended to be
the default condition for commercial and industrial
districts in urban areas.”
LZ4 High “Reserved for very limited applications such as
major city centers, urban districts with especially
high security requirements, thematic attractions and
entertainment districts, regional malls, and major auto
sales districts”

TABLE 2.8.2 Outdoor Lighting Zone Definitions from IDA Website (http://www.darksky.org/
ordsregs/l-zones.html) as Accessed May 10, 2008