Indoor Recessed Lighting for a Staircase

Sources

• Standards for indoor recessed lighting of staircases are based on two sources. First are local and state building codes that come from the International Residential Code, which is managed by the International Code Council, a nonprofit member organization. These codes are legally binding, since constructions that do not meet them are not approved for use. These mandates do not specify illumination levels or recessed lighting specifications. Guidelines for those must either come from a second source, experience or lighting manufacturers. Guidelines from secondary sources are not legally binding and are unaffected by code inspections. As an example of the latter, the North Coast Lighting Outlet, a lighting store, offers several guidelines for recessed lighting.

Requirements

• IRC rule 303.7 requires illumination for all parts of a staircase, including the landings and treads. Interior stairs need artificial lighting near each landing. The IRC does not specify the type lighting needed. It does state that all areas must have light levels of at least 1 foot-candle or 11 lux, as measured from the center of the treads and landings. These artificial lights are not needed at the top and bottom landings if a light source is already located directly over each stairway flight.

Guidelines

• North Coast Lighting Outlet recommends lighting levels for staircases based on their location. For living rooms, which are the most common location, up to 35 foot-candles are useful. Bedroom illumination drops to 25 foot-candles, while stairs from kitchens need up to 50 foot-candles. For coverage, each recessed light brightens an area up to four times its mounting height. For example, recessed lights mounted in 10-foot ceilings over stairs can cover 40 square feet. These downlights typically use baffles or open reflector trims.

Tasks

• A staircase is technically a task area, since it is only used for the act of traveling between floors and not for casual lounging. Homeowners may prefer more stringent standard for recessed task lights. It states that using a light with a 30-degree beam covers only three times the mounting height at the surface of the task. Therefore, a recessed light mounted 10-feet above the tread can cover only 30 square feet. Parabolic or reflector lamps are most commonly used for such applications.