The 2025 California Building Standards Code (Title 24) went into effect on January 1, 2026. If you submit permits in California, every application filed after that date has to comply with the new edition. And thanks to AB 130, which froze the state's ability to adopt mid-cycle amendments for residential construction, this code cycle is expected to remain in force through at least 2031. That makes it worth understanding thoroughly.
Most of the attention has gone to the energy code updates. Fair enough. But several of the changes that are generating plan check corrections right now have nothing to do with energy modeling. They affect structural calculations, height classification, fire protection requirements, and documentation expectations across every discipline.
Here are the eight Title 24 changes that I am seeing cause the most friction on California submittals.
1. ASCE 7-22 replaces ASCE 7-16 statewide
This is probably the biggest single change for structural engineers. California has adopted ASCE 7-22 as the referenced standard for seismic, wind, snow, and other environmental loads. That replaces ASCE 7-16, which had been the basis for the 2022 CBC.
What does that mean for your drawings? Revised seismic hazard maps and updated MCER values and site coefficients shift base shear and lateral system demands in several California regions. Wind speed maps and importance factors have changed too, which may increase or decrease wind pressures depending on project location. If you are carrying forward calculations from a 2022-code project and assuming the same design values, check them again. The inputs may have shifted underneath you.
On a practical level, this means any structural drawing set submitted after January 1 should reference ASCE 7-22 in the general notes, and the design values on the cover sheet need to reflect the updated maps. Referencing ASCE 7-16 values from the previous cycle is one of the fastest ways to get a correction notice that is entirely avoidable.
2. Occupied roofs count toward building height
Rooftop amenities have become standard on multifamily, hotel, and mixed-use projects across California. The 2025 CBC now addresses this directly: occupied roofs count toward building height calculations. That sounds straightforward, but the downstream effects catch people off guard.
If an occupied roof pushes a building into high-rise classification, it triggers stricter fire protection and structural requirements that may not have been part of the original design intent. Occupancy calculations now apply to usable roof areas, which affects egress width, plumbing fixture counts, and allowable occupant loads. Most occupiable roofs will need multiple means of egress, which has implications for stair design, exit pathways, and the overall layout.
For multifamily and hospitality projects with rooftop decks, pools, or outdoor dining, this is the kind of change that needs to be caught in schematic design. A correction notice during plan check can mean redesigning stairwells and fire protection systems when the structural steel is already ordered.
3. Battery Energy Storage Systems get their own classification
With the growth of lithium-ion battery installations across California, the 2025 CBC now classifies Battery Energy Storage Systems (BESS) more clearly and sets stricter fire and life safety standards for them. Projects that include BESS installations now need documentation for load management and coordination with the fire authority having jurisdiction.
This is new territory for a lot of design teams. If your project includes a battery room or rooftop BESS array, your drawing set needs to show the fire separation, ventilation, and suppression details that the new provisions call for. Plan reviewers are specifically looking for this documentation, and its absence is generating correction notices on projects that would have gone through without comment under the 2022 code.
4. Energy code baselines are tighter across the board
The California Energy Code (Title 24, Part 6) has always been more aggressive than the IECC, and the 2025 edition keeps pushing. Stricter building envelope requirements mean higher insulation R-values and tighter envelope performance targets. Fenestration limits on U-factor and Solar Heat Gain Coefficient (SHGC) have been revised downward. Mechanical system efficiency requirements, duct leakage limits, and ventilation rules have all gotten more demanding.
The practical impact is that energy modeling needs to happen earlier in design than many teams are used to. Assumptions about glazing ratios, insulation assemblies, and HVAC efficiency that worked under the 2022 code may blow your compliance margin under the 2025 edition. If you wait until construction documents to run the energy model and then discover you need to change your glazing spec or add continuous insulation, you are looking at the kind of late-stage redesign that kills project schedules.
5. Electrification readiness for new construction
New construction and major remodels now need to demonstrate all-electric readiness. That does not necessarily mean the building must be all-electric at occupancy, but the electrical infrastructure has to be designed to support full electrification. This requires electrical load calculations and verification of service capacity that account for future conversion of any gas systems.
On drawing submittals, plan reviewers are looking for electrical panel schedules and riser diagrams that reflect this future capacity. If your electrical drawings show a panel that is already near capacity with the current loads, the reviewer will flag it. The intent is that future electrification should not require a service upgrade, so the capacity needs to be designed in from the start.
6. Elevator lobby door locking provisions are relaxed
This one is actually good news. Under the 2022 CBC, the requirement for an exit within elevator lobbies limited flexibility in many floor plate configurations, especially in mid-rise and high-rise office and residential towers with compact layouts. The 2025 code allows locking devices on elevator lobby doors under specific conditions: visual notification of fire alarm activation in the lobby, automatic unlocking upon fire alarm activation, and specific hardware requirements.
For designers who have been contorting floor plans to accommodate lobby exit requirements, this opens up layout options that were previously non-compliant. It is worth reviewing your typical floor plate designs to see if this relief applies to any of your current projects.
7. Temporary structures face stricter oversight
The 2025 CBC strengthens oversight on temporary structures that remain in service for more than 180 days. Additional inspections are now required for extended-use temporary structures, with enhanced structural criteria for those that serve public occupancy. Usage duration, siting, and code compliance limits have been clarified.
This affects event spaces, modular offices, temporary facilities, and long-term installations that were previously treated as more or less permanent fixtures without the full code compliance review that a permanent structure would require. If your project includes temporary structures, check the new provisions before assuming the same permitting approach that worked last cycle.
8. Documentation standards are higher across the board
This is the change that does not have a single code section reference but shows up in correction notices across every discipline. The 2025 code emphasizes digital verification and stricter documentation checks. Plan reviewers in California are expecting more complete and precise documentation at submittal.
Practically, that means a few things: make sure your design criteria are clearly stated on the cover sheet and that they reference the correct code editions (2025 CBC, ASCE 7-22). Make sure your energy compliance documentation is included with the initial submittal, not promised as a follow-up. Make sure your structural calculations reference the correct site coefficients from the updated hazard maps.
The pattern I keep seeing on California projects is that plan check corrections are increasingly about incomplete or mismatched documentation rather than actual design deficiencies. The design might be fine, but if the drawings reference the wrong code edition or omit a required piece of documentation, the correction notice looks the same as a real compliance failure. And it costs the same amount of time to fix.
How this connects to jurisdiction amendments
California is a statewide code state, but local jurisdictions still adopt their own amendments. Cities and counties can add requirements on top of the CBC, and many do, particularly around energy, seismic, and fire protection. If you work across multiple California jurisdictions, you already know the difficulty of tracking which local amendments apply to each project.
This is the kind of problem that Callout's jurisdiction amendment feature was built for. You can upload a jurisdiction's local amendments as a PDF, and Callout will cross-reference them against the base model codes during your drawing review. Each finding is tagged with its source (model code, firm standard, or jurisdiction amendment) so you can see exactly where the requirement comes from.