PM-502.1 Common corridors and stairways: Every common corridor, interior stairway and exterior stairway shall be provided with artificial light capable of providing a minimum of 1 footcandle (11 lux) at floors, landings and treads. Continuous operation of the lighting system is required during all hours of occupancy except during those hours when there is sufficient natural light to comply with these requirements.

PM-502.2 Other spaces: All other spaces shall be provided with natural or artificial light sufficient to permit the maintenance of sanitary conditions, and the safe occupancy of the space and utilization of the appliances, equipment and fixtures.