for implementation of proper daylighting design that reduces energy
usage for electric lighting by 50 to 80%, provides occupants a
connection between indoor spaces and the outdoors, and increases
occupant productivity with reduced illness and absenteeism.
OPTION 1 - Glazing Factor Calculation: Complete the Glazing factor
calculation specified in the LEED reference guide to prove a
minimum 2% glazing factor is achieved in 75% of all regularly
OPTION 2 - Daylight Simulation Model: Create a computer simulation
demonstrating a minimum daylight illumination level of 25
footcandles in at least 75% of all regularly occupied areas.
OPTION 3 - Daylight Measurement: Record indoor light measurements
that prove a minimum daylight illumination level of 25 footcandles
in at least 75% of regularly occupied areas.
- Use of effective solar control strategies (overhangs) and high
performance glazings limit associated solar gains.
- Achieving this daylight credit will likely increase energy
savings in the Energy and Atmosphere credits. This is largely due
to savings in the electric lighting that results from well daylit
- Daylighting strategies can have synergies with other energy
efficiency strategies such as displacement ventilation.
- The USGBC calculation methods (requiring a two percent daylight
factor) can require prohibitively high interior illuminance levels
in climates with high exterior illuminance levels.
- Exclude spaces where tasks would be hindered by the use of
daylight, e.g., photography dark rooms and x-ray viewing
- Daylight glazing (above 7'-6") offers the most benefit for
harvesting daylight deeper into the space (although they do not
count towards IEQc8.2).
- This credit may have synergies with the lighting control
strategies required in IEQc6.1 and IEQc6.2.
- Consider non-tangible benefits of increased daylighting design,
including increased productivity, decreased absenteeism and errors,
reduced salaries for appealing work environments, etc.
- 58% of all California LEED Certified projects achieved this
credit for LEED v2.1.
Additional EDR Resources
Case Studies: High Quality Learning Environment Yields 38 Percent
Case Studies: Multi-Agency Library Benefits from Daylighting
Case Studies: An Integrated Campus Benefits From Its Desert
Case Studies: Skylighting Helps a Manufacturing Company Retain
Studies: Skylighting in Schools - A Healthy Advantage
Design Briefs: Building
Guidelines: Daylighting Guidelines
Guidelines: Skylighting Guidelines