Common areas in multi-family buildings include areas like interior hallways, lobbies, entertainment rooms, pool houses, club houses, and laundry facilities. Lighting requirements for these spaces depend on the characteristics of the buildings, as described below. Buildings three stories or less are classified as low-rise, and buildings four stories or more are classified as high-rise.

6.4.1          Low-Rise Multifamily

Lighting requirements in common areas of low-rise multifamily buildings depend on the percentage of the total interior common area in each building. Buildings where interior common area equals 20 percent or less to the floor area have one set of requirements, and buildings where the total interior common area is greater than 20 percent of the total floor area have different requirements.

A.   If the common area equals 20 percent or less of the total building floor area

In low-rise multifamily buildings where the total interior common area in a single building is 20 percent or less of the total floor area, all permanently installed lighting in interior common areas must be high efficacy and controlled by occupancy sensors.

B.   If the common area is greater than 20 percent of the total building floor area

In low-rise multifamily buildings where the total interior common area in a single building is greater than 20 percent of the total floor area, permanently installed lighting in common areas must meet the applicable nonresidential lighting requirements, and corridor and stairwell lighting must be controlled by occupant sensors.

The relevant nonresidential lighting requirements that apply in these cases are:

1.  §110.9 – Mandatory Requirement for Lighting Control Devices and Systems, Ballasts, and Luminaires

2.  §130.0 – Lighting Systems and Equipment, and Electrical Power Distribution Systems – General

3.  §130.1 – Mandatory Indoor Lighting Controls

4.  §140.6 – Prescriptive Requirements for Indoor Lighting

5.  §141.0 – Additions, Alterations, and Repairs to Existing Nonresidential, High-Rise Residential, and Hotel/Motel Buildings, to Existing Outdoor Lighting, and to Internally and Externally Illuminated Signs

These sections cover allowable equipment, controls requirements for various space types, allowable lighting power densities for various space types, and requirements for additions and alterations to existing buildings. More information about the nonresidential lighting requirements that apply in these scenarios can be found in Chapter 5 of the Nonresidential Compliance Manual.

In addition to meeting the applicable nonresidential lighting requirements listed above, lighting in corridors and stairwells in these buildings must meet the following occupancy control requirements:

1.  Occupancy controls must reduce stairway and corridor lighting power by at least 50 percent when the spaces are unoccupied.

2.  Occupancy controls must be capable of turning stairwell and corridor lighting fully On and Off from all designated paths of ingress and egress.

The lighting of staircases and stairwells is a significant safety concern; the best way to light stairs is with directional light from above, to maximize the contrast between treads and risers.

6.4.2          High-Rise Multifamily

Common areas in all high-rise multifamily buildings (four stories or greater) must meet all applicable nonresidential lighting requirements in the following sections:

1.  §110.9 – Mandatory Requirement for Lighting Control Devices and Systems, Ballasts, and Luminaires.

2.  §130.0 – Lighting Systems and Equipment, and Electrical Power Distribution Systems – General.

3.  §130.1 – Mandatory Indoor Lighting Controls.

4.  §130.4 – Lighting Control Acceptance and Installation Certificate Requirements.

5.  §140.6 – Prescriptive Requirements for Indoor Lighting.

6.  §141.0 – Additions, Alterations, and Repairs to Existing Nonresidential, High-Rise Residential, and Hotel/Motel Buildings, to Existing Outdoor Lighting, and to Internally and Externally Illuminated Signs.

These sections cover allowable equipment, controls requirements for various space types, allowable lighting power densities for various space types, and requirements for additions and alterations to existing buildings. More information about the nonresidential lighting requirements that apply in these scenarios can be found in Chapter 5 of the Nonresidential Compliance Manual.

Dwelling units within high-rise multifamily buildings must comply with the residential lighting requirements.