California’s Building Code Shift: Key Changes Starting in 2026
Every three years, California updates Title 24; the set of building standards that govern energy, structural safety, fire protection, indoor air quality, and more.
The 2026 cycle introduces sweeping changes, especially for residential and low-rise construction. Many of these changes reflect California’s goals around electrification, climate resilience, and healthier homes.
Below is a breakdown of the key changes and what they might mean for architects, builders, homeowners, and jurisdictions.
What’s Driving the Update
California faces growing pressure to reduce carbon emissions, respond to climate impacts (wildfires, heat, drought), and transition away from fossil fuels. The 2025 Energy Code update, which begins Jan. 1, 2026, is projected to result in about $4.8 billion in energy savings over time and reduce millions of metric tons of greenhouse gas emissions.
Also notable: recent legislation AB 306 places a six-year pause on further residential code updates (i.e. the 2028 residential cycle) unless narrowly exempted. That means the 2026 code is especially consequential, because it will govern residential standards through 2031 (with some exceptions).
Key Changes for Residential / Low-Rise Projects
1. Electric-First / Fossil-Fuel Limitation
New homes are expected to use all-electric systems; no natural gas hookups for major systems (heating, water heating) in many jurisdictions.
Heat pumps (for space heating/cooling) and electric water heaters become the standard.
Even for commercial kitchens or multifamily buildings, the code includes “electric-ready” requirements so switching to electric later is easier.
Implication: From early schematic design, you’ll need to size electrical infrastructure (main panels, circuits, backup or battery systems) and plan appliance layouts accordingly.
2. Solar-Ready / Net-Zero Energy Readiness
New homes must either be solar-ready or include photovoltaic (PV) systems.
Roof framing will need to be designed with PV (and likely battery) loading and orientation in mind.
Enhanced energy modeling and tighter thermal envelope requirements will be enforced.
3. Wildfire & Climate Resilience
In Wildland-Urban Interface (WUI) zones, stricter fire-resilient requirements will replace the older Chapter 7A rules.
New rules may require more fire-rated materials, upgraded venting and protection systems, and “home hardening” measures.
The code’s climate resilience ambitions also touch on heat mitigation, water strategies, and durability in extreme weather.
4. EV Charging Infrastructure
Every new multifamily building must be EV-ready.
If parking is assigned, a Level 2 receptacle per unit is required. If parking is shared/unassigned, receptacles must be installed at every spot.
For single-family homes, rough-in or wiring capacity will likely be required so future EV charging upgrades are simpler. (This is a trend under the new energy code.)
5. Structural & Seismic Adjustments
The seismic site classification method is being streamlined: only shear wave velocity will now be used. The old three-method approach is dropped.
Foundation and structural requirements may vary more precisely by site conditions under the new classification scheme.
High-rise classification is changing: now based on any occupied roof elevation (not just top occupied floor), which may reclassify some buildings and change life-safety system needs.
6. Accessibility, Indoor Air Quality & Healthy Home Measures
The code is strengthening accessibility requirements (especially for new homes, modifications, and ADUs).
Tighter ventilation, moisture control, and indoor air quality (IAQ) rules will be required to address health and comfort.
The Green Building Standards (CalGreen, Title 24 Part 11) continue to push requirements around low-VOC materials, water efficiency, and sustainable design; sometimes with voluntary “tiers” that local jurisdictions may adopt.
7. Embodied Carbon (Nonresidential)
For large nonresidential and school projects, California now requires addressing embodied carbon, either through reuse, life-cycle assessments, or material choices.
While this is more relevant for nonresidential buildings, its adoption signals the broader intent to extend carbon-consciousness across all building types.
The building code changes are intended to reduce cost pressures, bring predictability to housing development, and respond to needs for wildfire recovery, while balancing safety, climate, and environmental goals.
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Photo: Loren Elliott for CalMatters