Non-Residential Lighting and Title 24: Optimizing Energy Efficiency in Commercial Buildings

Indoor lighting is one of the largest consumers of energy in commercial buildings, accounting for about one-third of electricity use. The Title 24 California non-residential lighting standards aim to significantly reduce this energy consumption while maintaining high-quality lighting that supports effective task work. These standards are developed with input from lighting design professionals, manufacturers, and enforcement agencies across the state to ensure they are both practical and realistic.

Regulating Indoor Lighting Power

The primary mechanism for controlling indoor lighting energy use under the Title 24 energy standards is by limiting the allowed lighting power in watts installed in the building. Additionally, the standards require that all lighting equipment meet basic efficiency criteria and include controls to ensure that lighting operates efficiently.

Mandatory Lighting Controls

One of the simplest and most effective ways to improve lighting efficiency is by turning off lights when they are not in use. Under Title 24, all non-residential, high-rise residential, and hotel/motel buildings, whether in conditioned or unconditioned spaces, must have switching or control capabilities that allow lights to be turned off when unnecessary. Beyond simply turning lights off, the standards also emphasize reducing light output and power consumption when full light output is not required. Key mandatory lighting control requirements include:

• Light switches or controls in each room to allow manual control of lighting.
• Separate controls for general lighting, display lighting, ornamental lighting, and display case lighting.
• Occupant sensors in offices smaller than 250 square feet, multi-purpose rooms under 1,000 square feet, classrooms of any size, and conference rooms of any size.
• Partial ON/OFF occupant sensors in areas such as warehouses, library aisles, corridors, and stairwells.
• Multi-level control (dimming capability) for lighting systems with a density greater than 0.5 W/ft² in rooms larger than 100 square feet.
• Automatic daylighting controls in daylit areas over 100 square feet, unless the total installed general lighting is under 120 watts or the glazing area is less than 24 square feet.
• Demand responsive controls in buildings larger than 10,000 square feet, capable of automatically reducing lighting power by at least 15% in response to a demand response signal.

For a more detailed description of these and other mandatory control requirements, refer to the CEC Non-Residential Compliance Manual.

Lighting Trade-offs under Title 24

The Title 24 non-residential lighting standards impose restrictions on the total installed lighting power in a building, regardless of the compliance approach used. However, there is flexibility in where and how general lighting power is allocated within the building, as long as the total installed lighting power does not exceed the allowed limit. It’s important to note that trade-offs are not permitted between conditioned and unconditioned spaces.

Another type of lighting trade-off available under the Title 24 California standards is through the performance approach. This approach allows for trade-offs between the lighting system and the building envelope or mechanical systems. For example, if a building has a more efficient envelope or mechanical system than required by the prescriptive efficiency requirements, it may have a bit more flexibility in lighting power allowance to meet the overall energy budget. However, trade-offs are not allowed between indoor lighting and outdoor lighting or with lighting in unconditioned spaces.

Why Choose 5 Star Energy for Non-Residential Lighting Compliance?

At 5 Star Energy, we specialize in helping commercial buildings achieve Title 24 compliance by optimizing their lighting systems. Our team ensures that your lighting design meets all California Title 24 energy standards, from mandatory controls to lighting power allowances. Whether you’re designing a new building or retrofitting an existing one, we provide the expertise needed to ensure your project is energy-efficient, cost-effective, and compliant with all relevant standards.