Title 24 Energy Rules for Remodels

Many homeowners hear “Title 24” halfway through planning a remodel, usually when a designer mentions a compliance form or an inspector asks about light fixtures. The rules are real, but they are narrower than most people fear. For an existing home, California’s energy code generally applies to the parts of the house you change, not the whole building. This guide explains what Title 24 is, which remodel scopes trigger it, how additions and ADUs differ, and what to ask before your plans are final.

What Title 24 Is, and What It Is Not

Title 24 is the California Building Standards Code. Part 6, the Energy Code, sets energy efficiency requirements for buildings. Other parts cover other subjects. For example, the California Green Building Standards Code (CALGreen) is a separate part that addresses items like water use. This article covers the energy rules maintained by the California Energy Commission (CEC). You can read the agency’s overview on the CEC’s 2025 Building Energy Efficiency Standards page.

The code updates on a cycle. The 2025 edition took effect January 1, 2026, and the CEC says it applies to buildings whose permit applications are filed on or after that date. Projects permitted earlier fall under the previous edition. That detail matters if you are comparing advice from older articles or contractors.

When Does Title 24 Apply to a Remodel?

Title 24 applies to an alteration when the work changes an energy-related component of the home. The CEC treats an alteration as a change to the water heating, space-conditioning, lighting, electrical power distribution or building envelope that is not an addition. The code then applies to the altered portions, not to untouched ones.

The scope matters more than the room. A kitchen remodel that only changes cabinets and countertops is less likely to bring in energy requirements, while one that adds recessed lighting or new circuits is more likely to. Your local enforcement agency decides how the code applies to your permit, so treat this as general guidance rather than project-specific advice.

The Parts of Title 24 Homeowners Notice Most

Lighting

New or altered lighting must meet the Energy Code’s residential lighting requirements. In practice, that means high-efficacy sources and appropriate controls. For example, recessed downlights must use light sources certified for that purpose, and habitable spaces generally need wall-mounted dimmers or other required controls. Adding a few recessed cans is treated as a lighting alteration, not a ceiling alteration, according to CEC guidance, so it does not by itself trigger ceiling insulation work.

For kitchens and bathrooms, lighting is where most homeowners first meet Title 24. The cost implications are mostly about fixture selection and controls rather than structure. Our bathroom remodel cost guide and kitchen remodel cost guide for the San Fernando Valley explain where those items fit in a budget.

Windows

Replacement windows must meet limits on heat transfer and solar heat gain, with a performance-based alternative if a product does not meet the prescriptive values. Some small replacement scopes have exceptions. Because window lead times can be long, selecting compliant products early helps keep the schedule on track.

Heating, Cooling and Ductwork

Replacing a heating or cooling system brings equipment and duct requirements. Many HVAC alterations require field verification, such as duct sealing tests and refrigerant charge checks, performed by an independent HERS rater rather than the installer. When verification is required, the registered documentation is kept with the project’s compliance records. Heat pumps have a larger role in the 2025 code, which affects equipment choices in some projects.

Insulation and Roofing

Roof replacement can trigger cool roof requirements when more than half the roof is replaced, and insulation provisions may apply depending on what you are altering. The details depend on roof slope, climate zone, and materials, and published guidance differs on specifics. Confirm them with your roofer and the building department rather than relying on a general rule.

Additions and ADUs Follow Different Paths

An addition is treated differently from an alteration. New conditioned space must meet the Energy Code’s mandatory measures and either a prescriptive or performance compliance path. Heating and cooling for the new space typically require load calculations and proper sizing. Solar panels are generally not required for additions.

ADUs depend on how they are classified, according to the CEC’s ADU FAQs:

Local rules and state law change, so we confirm the classification and any exceptions before design starts. For more on ADU planning, see Can You Build an ADU in the San Fernando Valley? and our comparison of garage conversion versus a new ADU.

Who Checks Title 24 and How It Gets Documented

The state writes the code, but your local building department enforces it. In the City of Los Angeles, that is LADBS. Incorporated cities such as Beverly Hills, Santa Monica, Calabasas, and Thousand Oaks run their own departments, so the permit counter and paperwork differ by address.

Documentation depends on the scope. Many permitted projects include a compliance form prepared at design, installer certificates completed after the work, and, where verification is required, rater documentation. For some alterations, such as water heater or window replacements, enforcement agencies can choose to waive certain installation paperwork. Keeping these records matters at resale, because they show the work was permitted and inspected.

Trying to Figure Out What Your Project Triggers?

Whether a lighting change, a window replacement, or an addition pulls Title 24 into your project depends on the scope, your property, and the jurisdiction. Superior Home Builders can review your plans, coordinate the compliance documentation with your designer and the building department, and keep the project moving.

Planning Around Title 24 Before Plans Are Final

Compliance is easiest when it is part of the design, not a correction during plan check. Practical steps include:

• List the components you will touch. Lighting, windows, HVAC, roofing and insulation are the common ones.
• Select windows and equipment early. Compliance depends on product ratings, and lead times can affect the schedule.
• Ask about verification. If HVAC work is included, ask whether rater testing is required and who schedules it.
• Budget for fixtures and controls. High-efficacy lighting and required controls are part of the scope.
• Keep the paperwork. Compliance records and inspection sign-offs are useful at resale.

Our design process page explains how plans, engineering, and permits fit together, and our general contracting service covers the coordination.

Which Code Edition Applies to Your Project?

The permit application date determines the edition. Applications filed on or after January 1, 2026 fall under the 2025 Energy Code, and earlier filings fall under the previous one. If your project was submitted before that date and later revised, ask the building department how it is being reviewed.

For specific projects, see our services for kitchen remodeling, home additions and ADU construction, or browse our Signature Projects.

Frequently Asked Questions

Does Title 24 apply to my kitchen remodel?

It can. Cosmetic work like paint or new cabinet fronts generally does not. Adding or replacing lighting, changing circuits or altering ventilation or windows usually brings the relevant energy requirements into the project. Your local building department confirms how it applies to your permit.

Do I need a Title 24 report for a remodel?

Sometimes. Whether you need a compliance report depends on the scope and on how your local agency handles the permit. Projects with new lighting, windows or HVAC often involve compliance documentation, while purely cosmetic work does not. Ask your contractor or the building department early.

Does replacing windows trigger Title 24?

Generally yes. Replacement windows must meet limits on heat transfer and solar heat gain, or comply through the performance method. Small replacement scopes may qualify for exceptions, so confirm the details with your window supplier and the building department before ordering.

Do ADUs need solar panels?

It depends on the type. According to the CEC, a new detached ADU is treated as a newly constructed building and generally needs solar panels unless an exception applies, while attached ADUs and garage conversions are treated as additions and do not. Confirm your case before design.

How do I know which version of the energy code applies?

The permit application date decides. The 2025 Energy Code applies to applications filed on or after January 1, 2026, and the prior edition applies to earlier filings. Your building department can confirm which edition is being used for your project.