What is the maximum allowable spacing in feet between lights for equivalent illuminance of stairways?

The maximum allowable spacing between lights for achieving equivalent illuminance on stairways is set at 30 feet. This standard is based on the need to provide adequate visibility and safety for individuals using the stairs, which can often be a high-risk area in terms of slips and falls. Adequate lighting ensures that all steps are clearly visible, reducing the likelihood of accidents.

Choosing a spacing more than 30 feet could result in dark spots and areas with insufficient light, increasing the potential for hazards. Hence, maintaining this spacing standard is crucial for ensuring safety while also following established building codes and lighting standards designed to enhance visibility in critical areas like stairways.