Page 111 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

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To verify that the requirement for interior lighting is obtained, it is necessary to get
illumination information from the manufacturer on all interior fixtures which may light
any windows or other openings in the building. This information should include a
lighting intensity photometric table or figure which shows the angle of maximum
lighting intensity.

Exterior Lighting Requirements There are two main parts, each with several criteria, to
the exterior lighting requirements that must be met. The first main part of the exterior
lighting requirements is based on the ASHRAE/IESNA Standard 90.1-2004 for LEED
2.2 and 90.1-2007 for LEED 2009, Energy Standard for Buildings Except Low-Rise
Residential—Lighting Section 9, Exterior Lighting Section, Table 9.4.5. This table is
essentially identical in both versions. However, LEED 2.2 required stricter requirements
than in Table 9.4.5 in 90.1, while LEED 2009 has modified the requirement to meet the
standards in this table. Note that this standard does not apply to any low-rise residential
uses including single-family homes. Therefore, this part is subject to interpretation for
low-rise residential facilities (three habitable stories or fewer above grade); nor does
this part apply to manufactured houses and buildings that do not use either electricity
or fossil fuel. In addition, this does not apply to equipment or portions of building
systems that use energy primarily for industrial, manufacturing, or commercial
processes. Any project with these items should be examined individually by way of the
USGBC CIR process and/or guidances as are being developed.
The second main part of the exterior lighting requirements limits the light
distribution, particularly beyond the site, and differs according to the location of the
site and the typical zoning uses in the neighborhood.

Exterior Lighting Part 1: For all construction other than low-rise residential uses and
as further exempted, the first part of the project exterior lighting requirement for LEED
2009 states that the ASHRAE/IESNA Standard 90.1-2007, Exterior Lighting Section,
with errata, but without addenda, Table 9.4.5 lighting powers densities (LPDs) are not
exceeded. (LEED 2.2 formerly restricted Table 9.4.5. LPD levels to 50 percent for building
facades and landscape features and 80 percent for all other exterior areas.)
The criteria in Table 9.4.5 of the ASHRAE/IESNA Standard 90.1 are given in units
of watts per square foot, watts per lineal foot, or watts per unit relating to a specific type
of site feature, and are all referred to as lighting power densities (LPDs). The criteria are
divided into two categories: those that can be traded (flexibility on the areas and exact
light locations) and those that cannot be traded. Those that can be traded apply to
outside areas in general. The nontradable allowances are in addition to the tradable
allowances. For instance, in LEED 2009, if there is an uncovered parking lot next to a
building façade, then this parking lot is allowed the parking lot allowance (the value for
the Uncovered Parking Lot LPD as given in Table 9.4.5 of the ASHRAE/IESNA Standard
90.1), plus the special building façade light fixtures (totaling, at maximum, the Building
Façades LPD as given in Table 9.4.5 of the ASHRAE/IESNA Standard 90.1).
Examples of these LPDs from the ASHRAE/IESNA Standard 90.1 are given in
Table 2.8.1. All the wattages for the fixtures in each area should be added up and divided
by the appropriate unit: square feet, lineal feet, or each specific item (i.e., drive-up window),
and then calculations should confirm that each does not exceed the requirement of the
values in Table 2.8.1 for LEED 2009. Again, there are some exemptions listed. Do not