What is Title 24?

Posted on February 6, 2023February 6, 2023 by Jason Somers

When you want to construct a new building for your company or renovate your existing one, you must comply with the Title 24 regulations that were put in place as part of the California Energy Code. Title 24 outlines requirements that are designed to make companies more Eco-friendly, energy efficient, and cost effective. By keeping these regulations in mind during development, you shouldn’t encounter any energy code problems that cause unnecessary delays.

The list of Title 24 requirements is a lengthy one that can be difficult to understand. However, reading about the Title 24 guidelines should help you gain a better idea of what they mean and how they should be applied when you develop your next building. This guide offers a detailed summary of California’s Title 24 requirements.

Why is Title 24 Important?

Title 24 is a set of energy efficiency standards that are maintained by California. The purpose of these standards is to make sure that existing and new buildings are able to achieve a certain level of efficiency. They are also meant to help businesses preserve indoor and outdoor environmental quality.

These specific measures are described in the California Code of Regulations, which was implemented by the California Energy Commission. This commission is directly responsible for implementing, adopting, and updating energy efficiency in buildings. Local county and city enforcement agencies are given the authority to make sure that developers and owners comply with building codes that pertain to energy efficiency.

Energy efficiency standards have been in place since 1978. Their purpose is to reduce energy costs, lower greenhouse gas emissions, and make buildings more comfortable. These standards ensure that developers are able to use energy-efficient construction and technologies.

Why are Energy Standards Constantly Updated?

The California Energy Commission is required to adopt new standards for their electrical code every three years. These standards must be cost-effective for homeowners during the typical 30-year lifespan that buildings have. The main reason why these standards are updated regularly is because of how quickly advancements are made when it comes to technology and construction method efficiency.

Who Supports Energy Standards?

The energy standards that have been set by the California Energy Commission are currently supported by the Natural Resources Defense Council and the California Building Industry Association. Other environmental groups also support these standards.

What Buildings are Covered by Title 24?

The Title 24 regulations apply to all new construction of nonresidential and residential buildings. Additions and alterations to the same buildings are also covered. The only exceptions involve jails, prisons, and correctional centers.

Why Do Energy Standards Vary by Climate Zone?

Energy standards can vary depending on the climate zone since different measures are more cost effective in different climates. For instance, regulations that are cost-effective in extreme climates might be too expensive in milder climates. By separating measures by climate zone, it’s possible to guarantee that a specific building will be outfitted with features that are the most energy efficient for that area. In California, there are 16 separate climate zones.

California’s Title 24 Lighting Requirements

The indoor lighting power allowances have dropped by nearly 40% for entire buildings and 30% for certain areas in existing buildings. As for outdoor lighting power allowances, they have dropped by around 23%. It’s believed that changing to LED lighting can help buildings reduce their power consumption by a considerable amount to reach these guidelines.

Power adjustment factors (PAF) are also available. These adjustments are designed to offset the wattage in a specific space while completing compliance calculations. Developers are encouraged to use light shelves and horizontal slats for better efficiency. The exact lighting requirements are detailed below.

1. Luminaire Classification and Power

Luminaires situated in California buildings are required to come with a wattage and classification labeling. The max wattage needs to be placed on a permanent label.

2. Independent Manual Controls

Title 24 control requirements for lighting indicate that luminaries must contain controls that are independent from the controls found in other areas of the building. All rooms need to have separate manual switches for lighting. These switches should be outfitted with on-off functionality. Exceptions to this specific rule include:

• Arenas
• Auditoriums
• Malls
• Retail sales areas
• Wholesale showrooms
• Convention centers
• Work and storage areas in commercial and industrial buildings
• Psychiatric areas in health care facilities

General lighting should have controls that are separate from controls of any other lighting systems in the building. By keeping each type of lighting on a separate control, businesses are able to illuminate certain areas of the building while leaving the other lights off, which reduces total energy consumption.

3. Multilevel Lighting Controls

Multilevel lighting is regulated based on several different aspects of Title 24. This type of lighting needs to contain controls that provide businesses with the ability to reduce the lighting they use by a specific amount, which will make the buildings more comfortable and conserve energy.

Light fixtures like LED luminaires and low-voltage incandescent systems must have continuous dimming that ranges from 10-100%. Fixtures that are used in downlighting can come with dimming that ranges from 20-100% power. Fixtures like compact fluorescent lights and track lighting need to have a minimum range of 30-70%.

The fixtures that are regularly used in surface mount and recessed lighting can have one step in the following ranges:

• 20-40%
• 50-70%
• 75-100%
• 100% power

The purpose of these requirements is to bolster energy efficiency by delivering options that allow for energy use to be minimized. If businesses are able to dim some of their lights, they’ll use less energy and consume less resources.

4. Shutoff Controls

Shutoff controls are designed to reduced lighting automatically in unoccupied spaces. These controls are available as occupant-sensing controls or automatic time switches. A single control can only cover 5,000 square feet of space or less. Loading areas and parking garages can use partial-off strategies instead, which means that lighting needs to be reduced by 50% when vacant. The only type of lighting that’s exempt from these guidelines is emergency lighting.

5. Outdoor Lighting

The outdoor lighting specifications outlined in Title 24 depend on the lighting zone that a building is in. Lighting zones are meant to indicate the level of light that the surrounding environment provides. These ratings can range from LZO to LZ3. An LZ0 area is one where there’s a very low level of light in an undeveloped area. LZ3 is used to indicate a high level of light in an urban area.

All outdoor lighting is based off the backlight, uplight, and glare (BUG) system. The purpose of this system is to identify how well the surrounding lighting minimizes glare and backlight to reduce energy consumption and light pollution. The worst ratings are G5, U5, and B5. In comparison, the best ratings are G0, U0, and B0.

6. Daylighting Controls

Title 24 requirements govern daylighting as well. Daylighting involves strategically placing windows and similar openings to allow natural light to illuminate building interiors during the daytime hours. These regulations are separated into three zones, which include skylit zones, primary sidelit zones, and secondary sidelit zones.

Skylit zones are areas that are mainly lit by skylights. These zones are equal to the area the skylight illuminates plus an overall distance of 0.7 times the skylight’s height extending out from the skylight’s edge.

Primary sidelit zones are areas that obtain light in the immediate vicinity of adjacent windows. This zone is equal to one window height deep as well as half the window height on both sides.

Secondary sidelit zones are distant areas that are still able to obtain some illumination from these windows. This zone is equal to two window heights deep as well as one window width plus around half of the window height wide.

Any areas that obtain daylighting need to be equipped with automatic daylighting controls, which can reduce energy consumption. These requirements are maintained in different situations, which include:

• The room comes with 24 square feet or more of glazing
• The room has a total lighting power of at least 120 watts
• Part of the area is in a primary sidelit zone or skylight zone
• The lights offer general lighting as opposed to display or decorative lighting

Daylighting in the above areas needs to come with multilevel lighting. Large enclosed places must also include a specific amount of daylighting. In the event that the floor area below a roof is larger than 5,000 square feet and the height of the ceiling is more than 15 feet, 75% or more of the area needs to be positioned in a primary daylit or skylit zone.

PAF credits are available for buildings that are outfitted with modern daylighting systems, which include dimming and off controls, clerestory windows, horizontal slats, and light shelves. The credit can be either 5% or 10% depending on which systems you install.

Keep in mind that Title 24 regulations require precise calculations to determine which areas of your building are in daylighting zones. Since these calculations are complex and the layout of every building is unique, you may need to obtain assistance from a professional contractor to make these calculations.

Regardless of the type or size of commercial building you’re developing, Title 24 regulations must be followed during development. Fines could be assessed if the building doesn’t adhere to these guidelines.