Unlike artificial electric lighting, natural interior daylight requires no energy.
    Kids do better in the school where well-designed natural interior daylight is used for lighting the classroom. (Image: Henning Larsen Architects)

A campaign to reduce our carbon emissions (and enjoy nicer lighting) in our buildings.

Natural Interior Daylight Initiative encourages homeowners, architects and building owners to use daylight as a primary light source.


Natural interior daylight offers a multitude of benefits beyond energy savings. It is the highest quality light source available for interior environments, it is flicker-free and it provides excellent color rendering and color balance. And natural interior daylight is one of the fastest greenhouse gas reducing paybacks you can buy, because it shrinks both energy bills and re-lamping maintenance costs. The fact is, introducing daylight into buildings provides energy savings, excellent lighting quality and more beautiful interior spaces. 

  1. Does natural interior daylighting pay for itself?

    Lighting accounts for roughly one third of electricity used by commercial or educational facilities in the United States. Whereas natural interior daylight requires no energy beyond sunlight. And Natural interior daylight is about 10-times more efficient then rooftop PV cells for lighting a room. 

  2. How do students preform under natural interior daylight?

    There is also plenty of evidence that daylighting improves occupant productivity in both schools and offices. Especially in learning environments, skylit classrooms provide a natural and stimulating space for teacher and student. While studies show that poor lighting adversely affects learning, daylighting has been proven to increase student performance in math and reading scores, as well as improving attendance. 

  3. How do office workers preform under natural interior daylight?

    Studies show that office workers have few sick days. The human performance numbers in daylighting systems are important because the ROI for daylighting installations can sometimes be a difficult sell. In fact, the human performance gains can outweigh the energy savings, where human performance can be measured in financial terms.

  4. What are the daylighting benefits for industrial buildings?

    Studies show that factories that employ natural interior daylight experience few product defects. The human productivity gains from daylight harvesting alone are significant, which has been proven to raise morale, increase productivity of students and workers, decrease product defects for numerous industries, and even increase retail sales.