Design & Engineering · San Diego

Does San Diego’s New Energy Code Apply to Your Remodel or Addition?

California’s 2025 Energy Code took effect on January 1, 2026, and San Diego enforces it exactly as written, with no local amendments. Here is what the code actually covers, when it applies to a remodel or addition instead of only new construction, and where to check the requirements yourself.

1. What the 2025 Energy Code is

California’s Energy Code is Part 6 of Title 24 of the California Code of Regulations — the statewide energy-efficiency standard for buildings, covering things like insulation, lighting, water heating and window performance. The California Energy Commission (CEC) updates it on a regular cycle, and the current version is officially called the 2025 Energy Code, even though homeowners often refer to it by the year it took effect, 2026.

The CEC states plainly that the standards “include requirements in the Energy Code (Title 24, Part 6)” and apply to “newly constructed buildings and alterations and additions to existing buildings.” That second half is the part many homeowners miss: this is not only a new-construction rule.

The code is administered at the state level by the CEC, but it is enforced locally, project by project, by the building department that reviews your permit application. For a San Diego project, that’s the Development Services Department — which is also the office that issues your building permit, checks your plans, and collects the fees discussed later in this guide.

2. When it took effect, and what applied before

The California Energy Commission ties the applicable code version to the date a building permit application is submitted, not the date construction starts or finishes. The prior cycle, the 2022 Energy Code, applied to permit applications submitted on or after January 1, 2023. The current cycle replaced it on January 1, 2026.

Practically, that means a remodel or addition permit filed in December 2025 could still be reviewed under the 2022 Energy Code, while the same project filed a few weeks later falls under the 2025 Energy Code. If your project has been sitting in the design phase for a while, it’s worth confirming with your design team which cycle your specific permit application will fall under.

3. Does it apply to remodels, or just new construction?

Yes. The Energy Code’s stated scope covers new buildings and alterations and additions to existing ones, so a whole-home remodel, a room addition or a new single-family home are all within scope of the same code — they are just reviewed differently depending on what the project touches.

4. How San Diego enforces it locally

Some California cities adopt the state code with local amendments that make it stricter in certain areas. San Diego does not do that with the Energy Code: the city’s Development Services Department lists it as enforced “as published, with no local amendments.” That means a San Diego project follows the same statewide rules as anywhere else in California — there is no separate San Diego energy chapter to research on top of it.

The same 2025 code update cycle also touched other codes the city enforces, including the Building Code, Residential Code, and Green Building Standards Code (CALGreen), on that same January 1, 2026 effective date. If your remodel or addition also involves structural work or new plumbing fixtures, ask your design team whether any of those companion updates affect your plan set, since they moved on the same calendar as the Energy Code.

• Energy Code (Title 24, Part 6): 2025 edition, effective January 1, 2026
• Building, Residential, Electrical, Mechanical, Plumbing and Fire Codes: also updated for 2025, effective January 1, 2026
• Green Building Standards Code (CALGreen): part of the same 2025 update cycle

5. Permit fees tied to state code compliance

A few of the fees on San Diego’s construction permit fee schedule exist specifically because the state requires them on every permit, separate from the city’s own plan check and inspection charges. These are calculated off your project’s permit valuation, not a flat number, so the dollar amount changes with project size.

None of these fees are Energy Code fees specifically — the CEC does not charge a separate state fee for energy compliance review. They’re listed here because they show up on the same permit application that carries your Energy Code compliance documents, and homeowners are sometimes surprised to see state-level line items mixed in with San Diego’s own plan check and inspection fees.

6. What this means for your project

If you’re planning a whole-home remodel or a home addition in San Diego and haven’t submitted for permit yet, your project will very likely be reviewed under the 2025 Energy Code rather than the 2022 version. That’s worth raising with your design and engineering team early, before floor plans and window schedules are finalized, since energy compliance documentation is prepared as part of the plan set you submit with your permit application — it isn’t an afterthought added later.

If your project is specifically about adding solar for a new home, that’s governed by a related but separate part of the code; see our guide to Title 24 solar requirements for new construction for that angle. This guide is about the broader 2025 update and how it reaches remodels and additions, not just new homes.

The practical takeaway for most homeowners is timing, not fear: nothing about the 2025 Energy Code should stop a remodel or addition from moving forward, and it does not, on its own, tell you what your project will cost. What it does mean is that your architect or engineer needs to design to the current standard from the first set of drawings, rather than updating plans mid-project because an older code cycle was assumed. Raising the question with your design and engineering team at the permit-planning stage, alongside the fees you’ll owe, keeps the schedule predictable.