What is Title 24?

The Energy Code is updated every three years to reflect advances in building technology and energy performance. The most recent update, known as the 2025 Energy Code, took effect January 1, 2026 and continues California’s efforts to improve building efficiency and reduce greenhouse gas emissions.

Because energy efficiency reduces energy costs for homeowners and impacts on the environment, building standards are an important part of California’s future. Before a city or county in California will grant a building permit, the current energy code requires submission of a Title 24 Energy Report (also called Title 24 energy calculations) to verify that the building design complies with the Energy Code.

The good news is that California’s goal of reducing home energy consumption can be achieved without sacrificing architectural design or settling for undesired products. For architects, dealers, and homeowners in California who prefer the clean aesthetic and performance of products from Western Window Systems, one compliance pathway offers additional flexibility: the Performance Method.

The Performance Method Advantage

There are two primary methods of compliance under Title 24: Prescriptive and Performance. Both require detailed information about the construction and energy efficiency of the building, but the Performance Method offers several advantages for projects that prioritize architectural flexibility.

The Prescriptive Method

The Prescriptive Method is typically the simplest approach to Title 24 compliance. However, it is also the least flexible because each building component must meet prescribed minimum energy requirements individually.

This approach may require design compromises, additional insulation, or potentially expensive energy upgrades to meet code requirements. In some cases, this can also increase construction costs or limit glazing options.

The Performance Method

The Performance Method requires more effort to demonstrate compliance but offers the greatest level of flexibility and often the most accurate representation of a building’s energy performance.

Using state-approved energy modeling software, the minimum level of energy efficiency required for compliance is calculated based on the overall building design. Because compliance is based on the total performance of the home rather than individual components, the Performance Method allows for more design flexibility and greater trade-offs between systems.

For example, this method may allow architects to incorporate larger areas of glass or unique window configurations while maintaining compliance through improvements elsewhere in the building design.

For this reason, the Performance Method is commonly used for custom homes, architect-driven designs, and larger additions.

Three Easy Steps for Compliance

1. Determine the compliance method being used for the project.Most new construction homes, custom homes, and large additions will utilize the Performance Method.
2. Work with an energy consultant to model the project.Quote the project using Western Window Systems products and coordinate with an energy consultant in your area to complete the Title 24 calculations. Costs will vary depending on square footage and project complexity.
3. Contact your Western Window Systems representative. Your local Western Window Systems representative can provide additional guidance and help coordinate with your design and energy consulting teams throughout the Title 24 process.

Energy Consultants

Learn More About Title 24

To learn more about the California Energy Code and the latest Title 24 updates, visit the California Energy Commission website at energy.ca.gov.