<answer>Daylighting</answer> is the oldest method of interior lighting. <answer>Daylighting</answer> is simply designing a space to use as much natural light as possible. This decreases energy consumption and costs, and requires less heating and cooling from the building. <answer>Daylighting</answer> has also been proven to have positive effects on patients in hospitals as well as work and school performance. Due to a lack of information that indicate the likely energy savings, daylighting schemes are not yet popular among most buildings.
What is the oldest method of interior lighting? 
Daylighting