Electrical–Restrooms and classrooms are now exempt from multi-level dimmers. Conference rooms and restrooms must be controlled using vacancy sensors.

In terms of lighting control interaction with mechanical equipment, vacancy and occupancy sensors will transmit a signal to the mechanical system indicating occupancy status of certain spaces including small offices and conference rooms. These signals are typically sent via low-voltage data cable from the sensor to the BMS system or directly to the mechanical equipment controller.

"For smaller projects that consist of renovating a single meeting room or two, a contact closure relay device can be installed to avoid larger impact to the existing lighting control system," Vakil tells GlobeSt.com. "Furthermore, lighting-power density allowances in watts per square foot have decreased by more than one-third since 2016. This decrease in lighting allowances has forced all new lighting fixtures to be LED type with low wattages. It's a new era outside as well. Outdoor lighting changes include reduced lighting power allowance."

From 2016 to 2019, lighting power density watts per square foot have decreased by 36%.

"When considering design, LEDs are to be used as much as possible. LEDs with low-maximum-wattage ratings should be specified to comply with the new allowed lighting-power densities," Peck-Kriss tells GlobeSt.com. "Ornamental lighting, which can be used to gain a wattage allowance, should be considered. Some alterations to walls, new lighting or relocation of area controls will trigger Title 24."

Mechanical–The specifications on the mechanical side are far less extensive than the electrical. There are revised efficiencies for mechanical equipment and an upgraded filtration requirement for outside air to MERV-13 filters along with ventilation control changes.

Design considerations include HVAC and lighting controls integration. Certain space types–small offices and all conferences rooms among others–now require integration of lighting and HVAC controls to reduce airflow when spaces are unoccupied.

"This demands a higher upfront cost and requires more coordination between designers and contractors, but it will lower energy use when spaces are unoccupied," Goldberg tells GlobeSt.com.

Key Title 24 Takeaways

First, because of the greatly reduced lighting power density values, use LEDs across the job if possible.

Second, make sure to assess lighting compliance early in the project.

Finally, expect increased cost for controls due to HVAC/lighting-sensor integration.