Common areas in multi-family buildings include areas like interior hallways, lobbies, entertainment rooms, pool houses, club houses, and laundry facilities.
Buildings of three stories or fewer are classified as low-rise. For buildings higher than three stories the Nonresidential Standards apply to all of the common areas.
A. In low-rise multi-family buildings with four or more dwelling units where common areas are 20% or less of the building area, lighting for common areas must be high efficacy, or controlled by an occupant sensor. Occupant sensors used in common areas may have the capability of turning the lights on automatically.
B. In buildings where common areas are more than 20% of the building area, lighting in those common areas must comply with the nonresidential lighting requirements in §110.9, §130.0, §130.1, §140.6, and §141.0.
The quality of light provided in common areas of apartments, condominiums, and townhouses should be particularly high, because older or visually impaired residents must be able to find their way safely through spaces that may contain unexpected obstacles. Providing a sufficient level of light is essential.
C. Lighting in corridors and stairwells of multi-family buildings must be controlled by occupant sensors that reduce the lighting by at least 50%.
The lighting of staircases and stairwells is a particular safety concern; the best way to light stairs is with directional light from above, to maximize the contrast between treads and risers.
Example 6-31: Multifamily common areas: Low rise
Question
Does the lighting for an interior common-area hallway of a low-rise residential building with four or fewer dwelling units have to comply with the Residential or Nonresidential Lighting Standards?
Answer
No, the lighting of an interior common-area hallway of a low-rise residential building with four or less dwelling units must comply with the residential lighting Standards.
Example 6-32: Multifamily common areas: High rise
Question
Does the lighting for an interior common-area hallway of a high rise residential building have to comply with the Residential or Nonresidential Lighting Standards?
Answer
The lighting of an interior common-area hallway of a high rise residential building must comply with the Nonresidential Lighting Standards. All the lighting in common areas must comply with the Nonresidential Standards; lighting inside the dwelling units must comply with the residential lighting Standards.
Hallways and stairwells are required to have partial on/off occupancy sensors that switch off at least half the lighting load when the hallway or stairwell is unoccupied.