For lighting in stairways and common halls in residential occupancy, what is the minimum wattage standard for incandescent light bulbs required per 200 square feet?

The minimum wattage standard for incandescent light bulbs in stairways and common halls in residential occupancy is based on the need to ensure adequate visibility and safety in these spaces. For every 200 square feet, the requirement is set at 60 watts. This wattage is considered sufficient to provide enough illumination to prevent accidents and improve safety for individuals moving through these areas, which are often used during both day and night.

Proper lighting in stairways and common halls is crucial as these are high-traffic areas where visibility can significantly impact safety. The 60-watt standard is a well-established guideline that balances the need for adequate lighting while also considering efficiency and energy usage. Using lower wattage could compromise visibility, increasing the risk of falls or other hazards.

Thus, adhering to the standard of 60 watts per 200 square feet helps to maintain a safe environment, demonstrating the importance of following established guidelines for lighting in residential settings.