Page 321 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

LEED Indoor Envir onmental Quality 283

above 7.5 ft from the floor are usually designed for daylighting purposes (but not for
views). Many birds are injured each year by flying into glazed surfaces. Consideration
should be given to using etched glazing or other means of modifying glazing so that
the modified exterior reflectances aid in reducing these mishaps.

IEQ Credit 8.1: Daylighting and Views—Daylight (75% of Spaces)
IEQc8.1 is worth one point in both LEED 2.2 and LEED 2009. IEQc8.1 has major
differences between the two LEED versions (2.2 and 2009) and has some of the options
renumbered even though the intent remains similar between the two versions.
Therefore, a separate listing of the requirements for each is given. The intent is first
given in the version 2.2 section.
USGBC Rating System (LEED 2.2)
LEED-NC 2.2 lists the Intent, Requirements, and Potential Technologies and Strategies
for IEQc8.1 as follows:
Intent (LEED 2.2 and LEED 2009)
Provide for the building occupants a connection between indoor spaces and the outdoors
through the introduction of daylight and views into the regularly occupied areas of the
building.
Requirements (LEED 2.2)
LEED 2.2 OPTION 1—CALCULATION
Achieve a minimum glazing factor of 2% in a minimum of 75% of all regularly occupied areas.
The glazing factor is calculated as follows:
Glazing Factor = Window Geometry Factor × (Window Area [SF]/Floor Area [SF] ) ×
(Actual T / Minimum T ) × Window Height Factor
vis vis
OR
LEED 2.2 OPTION 2—SIMULATION
Demonstrate, through computer simulation, that a minimum daylight illumination level of
25 footcandles has been achieved in a minimum of 75% of all regularly occupied areas.
Modeling must demonstrate 25 horizontal footcandles under clear sky conditions, at noon,
on the equinox, at 30 inches above the floor.
OR
LEED 2.2 OR LEED 2009 OPTION 3—MEASUREMENT
Demonstrate, through records of indoor light measurements, that a minimum daylight
illumination level of 25 footcandles has been achieved in at least 75% of all regularly
occupied areas. Measurements must be taken on a 10-foot grid for all occupied spaces and
must be recorded on building floor plans. In all cases, only the square footage associated
with the portions of rooms or spaces meeting the minimum illumination requirements can
be applied towards the 75% of total area calculation required to qualify for this credit. In all
cases, provide daylight redirection and/or glare control devices to avoid high-contrast
situations that could impede visual tasks. Exceptions for areas where tasks would be
hindered by the use of daylight will be considered on their merits.
Potential Technologies and Strategies
Design the building to maximize interior daylighting. Strategies to consider include building
orientation, shallow floor plates, increased building perimeter, exterior and interior permanent