Green Building Chapter Summary / FAQs
What are Green Building Codes:
The state sets certain minimum building code standards every 3 years, which local jurisdictions must adopt and enforce. The Town Council adopts these codes by reference and they are generally contained in Fairfax Municipal Code. The 2025 state building code update will go into effect on January 1, 2026.
Green building codes are a certain type of building code that are designed to reduce environmental impacts. These requirements encourage practices such as:
• Using less energy and water,
• Reducing reliance on fossil fuels,
• Recycling construction waste,
• Improving indoor air quality, and
• Supporting healthier, more resilient communities.
California’s statewide green building code, known as CALGreen (Title 24, Part 11), was first adopted in 2010 and is updated every three years.
In addition to “green” building codes, “reach” codes, may be adopted locally to go beyond the state regulations to reflect local priorities, such as wildfire risk, seismic safety, or climate action goals.
Tier 1 of the Green Building Code
In 2019 and 2022, Fairfax has adopted Tier 1 of the Green Building Code. Tier 1 are voluntary measures that the state publishes that jurisdictions can opt-into and enforce. They go above and beyond at encouraging electrification, efficiency, and resilience.
AB 130 – A pause on all Green Building Code Updates Until 2031 Until recently, local jurisdictions have been authorized to adopt local amendments to the state building codes based on localized conditions and priorities. However, effective October 1, 2025, AB 130 pauses local jurisdictions’ ability to modify building codes (including green building and reach codes) in order to encourage housing development.
What can the town still do given AB 130?
As referenced in the staff report, there are a few exceptions to AB 130 like if jurisdictions have had similar codes in place before the October 1st deadline. Legal review has determined that adopting Tier 1 of the 2025 Code is substantially similar to the adoption of Tier 1 completed in 2022 and Town is implementing that exception to the assembly bill.
Flexible Compliance Options:
In 2022, Fairfax adopted local green building standards and reach codes including Marin County’s Flexible Compliance Pathway (FlexPath) for remodels. FlexPath allows projects to achieve a target score by selecting from a menu of energy efficiency and electrification measures, giving builders and homeowners flexibility to implement measures that best suit their project.
Feedback from the building community and building department staff since adoption in 2022 indicates that the Flex Path is reasonable to comply with and to enforce. In a recent meeting, Marin Builders Association expressed appreciation for the flexibility the policy offers, valuing that it lets homeowners and builders choose what measures make the most sense for the home, as opposed to prescriptive requirements that may not make sense within the project scope. Flex Path offers cost-effective options that contribute to Fairfax’s Town Council adopted climate goals.
All remodel projects over 200 square feet are required to go through the Flexible Compliance Pathway, EXCEPT certain hardship and infeasibility variables such as:
- Compliance disproportionate to overall project cost;
- Strict compliance with the standards would create or maintain a hazardous condition(s) and present a life safety risk to the occupants;
- Conflicts with State standards;
- Measures impair a listed historic structure.
What’s in the Flex Path Code:
The Flex Path menu contains a mix of energy efficiency and electrification measures. Generally, the electrification measures such as heat pump water heater or heat pump HVAC conversion from gas have a high point value and can be a simple way to achieve the target score. The policy has proven to be an effective tool to encourage home appliance electrification, in conjunction with the Electrify Marin rebate program. Bay Area Air District zero-NOx appliance rules are scheduled to ban the sale of gas water heaters and furnaces in 2027 and 2029, respectively, so the Flex Path’s encouragement of heat pumps makes Marin homeowners and building professionals better prepared for the transition.
What’s in the 2025 Tier 1 Code:
- EV-ready wiring for single-family homes
- Electric Vehicle Supply Equipment (EVSE) requirements for multifamily and nonresidential buildings
- Embodied carbon compliance for large projects
- Bicycle parking (multifamily & nonresidential)
- Heat pump and photovoltaic baselines in the energy code Comparison to other Marin Jurisdictions
Jurisdiction
2022
CALGreen Tier
1 Adopted?
Flexible Compliance
Pathway adopted
pre 2025?
Planning to adopt
2025 Tier 1?
Readopt
FlexPath?
Unincorporated
Marin Yes Yes
Yes, only nonenergy and EV
measures
Yes
Corte Madera No, just some
EV reach codes Yes No Yes
San Anselmo Yes Yes No Yes
Larkspur Yes No Yes —
Mill Valley Yes No Yes Yes
Novato Yes No Yes —
San Rafael No Yes No Yes
Sausalito No No In conversation —
Tiburon Yes Yes but never
enforced Yes Yes