LEED AP with Operations and Maintenance (O+M ) Practice Exam

The illumination level measured with lights on must not exceed what percentage above the level measured with lights off for light pollution reduction credit?

1. 10%

2. 20%

3. 30%

4. 40%

The correct answer is: 20%

For the light pollution reduction credit in LEED, the requirement is based on limiting the illumination levels from a building to minimize glare and light trespass that can affect both the environment and neighboring properties. The criteria stipulate that the illumination level measured with the lights on should not exceed 20% above the level measured with the lights off. This 20% threshold is designed to ensure that the lighting has minimal impact on the surrounding ecosystem and human habitation. It strikes a balance between providing adequate lighting for safety and use while reducing excessive brightness that could contribute to light pollution. This standard reflects best practices in sustainable building operation and the importance of responsible lighting design. The other options suggest thresholds that would allow for greater light pollution, which does not align with LEED's goals of promoting sustainability and reducing environmental impact. By having a clear standard of 20%, LEED sets realistic parameters that encourage building owners and operators to assess and manage their lighting systems effectively.