While the requirements for the various codes and regulations remain the same, the reorganization and consolidation into the Unified CWUI Code, adopted as Title 24, Part 7, is a major milestone for California making a simpler process for builders and local officials across the state.
CalFire’s long-standing Wildland-Urban Interface (WUI) Workgroup (Office of the State Fire Marshal) completed a proposal for the CWUI Code, modeled after the International Wildland-Urban Interface Code. Then the California Building Standards Commission created and adopted the CWUI Code, effective January 1, 2026, with counties and cities expected to adopt the CWUI Code by January 2027.
The new California Wildland-Urban Interface Code (CWUI Code) was adopted as Title 24, Part 7, which consolidated wildfire-related provisions that had been scattered throughout the California Building Code, Residential Code, Fire Code, and other California documents and adoptable regulations, such as the State Minimum Fire Safe Regulations.
The various wildfire-related sections include the following, with the arrangement and format of the CWUI Code in Title 24, Part 7 defined on the ICCSafe.org website. The various wildfire-related sections include:
1. Existing Chapter 7A of the Building Code,
2. Chapter 49 of the Fire Code
(vegetation management around structures),
3. Chapter 337 of the Residential Code, and the
4. State Minimum Fire Safe Regulations.
The CWUI Code presents an opportunity for cost-effective compliance with critical codes and regulations for new construction, hardening of existing construction and defensible space through clarity, oversight and enforcement.
While the requirements for the various codes and regulations remain the same, the reorganization and consolidation into the Unified CWUI Code, adopted as Title 24, Part 7, is a major milestone for California making a simpler process for builders and local officials across the state.
CalFire’s long-standing Wildland-Urban Interface (WUI) Workgroup (Office of the State Fire Marshal) completed a proposal for the CWUI Code, modeled after the International Wildland-Urban Interface Code. Then the California Building Standards Commission created and adopted the CWUI Code, effective January 1, 2026, with counties and cities expected to adopt the CWUI Code by January 2027.
The requirement that California cities and counties adopt a California Wildland-Urban Interface Code (CWUIC) by January 2027 is actually the result of several pieces of legislation and regulatory actions, rather than a single bill.
AB 38 (Wood, Chapter 391, Statutes of 2019): This bill required a comprehensive review of wildfire mitigation standards following the devastating 2017–2018 wildfire seasons. It directed state agencies to strengthen home hardening and defensible space requirements and led to recommendations for a more unified wildfire code.
AB 3074 (Friedman, Chapter 259, Statutes of 2020): The most significant legislation as It set in motion many of the regulatory changes that were later incorporated into the new CWUI Code. This bill required the Board of Forestry to develop regulations for the 5-foot ember-resistant "Zone 0," expanded wildfire prevention requirements around structures and accelerated updates to Fire Hazard Severity Zone mapping.
AB 211 (Committee on Budget, Chapter 574, Statutes of 2022): This bill substantially revised Government Code §51179 by requiring local agencies to:
- adopt by ordinance the State Fire Marshal's updated Moderate, High, and Very High Fire Hazard Severity Zones within 120 days after receiving the State's recommendations; - prohibit local governments from lowering State-designated hazard classifications; and
- authorize only equal-or-greater hazard designations. Once those hazard maps are adopted, the applicable Title 24 building standards—including the CWUIC—apply within those designated zones.An updated set of State Minimum Fire Safe Regulations (FSR) were adopted in April 2023. The California Board of Forestry and Fire Protection (BOF) originally adopted the State Minimum Fire Safe Regulations in 1991. And, as of July 2021, the regulations are required in the Very High Fire Hazard Severity Zones (VHFHSZ) for Local Responsibility Areas (LRA), as well as in the State Responsibility Area (SRA).
The State Minimum Fire Safe Regulations set standards designed to save lives by focusing on three criteria:
unimpeded access by large firefighting apparatus;
concurrent evacuation of residents and workers; and
unobstructed traffic circulation during ongoing wildfire emergencies.
The CWUI Code reorganized the State Minimum Fire Safe Regulations into multiple chapters included in Appendix H of the CWUI Code:
Chapter 1 Administration (California Board of Forestry and Fire Protection, California Code of Regulations Title 14, Purpose, Scope, Definitions, Exceptions to Standards, Same Practical Effect, Modifications, Exemptions, Oversight and Enforcement)
Chapter 2 Definitions (California Code of Regulations Title 14, Definitions)
Chapter 4 Wildland-Urban Interface Area Requirements (California Code of Regulations Title 14, Access, Water Supply, Road Standards, Signage)
Chapter 6 Fire Protection Requirements (Strategic Ridgelines, Public Resources Code (PRC) 4290, Fire Safe Development Regulations)
The State Fire Marshal’s long-standing Wildland-Urban Interface (WUI) Workgroup will continue to review and propose revisions and improvements to the CWUI Code. Given California will continue to adopt fire focused legislation, this reorganization and consolidation will facilitate integration of new standards.
Additional Resources:
CalFire’s Information Bulletin 26-004 informs the public about the 2025 California Building Standards Code (CBSC) the publication – its effective date, availability, and significant changes. The CBSC compiles building standards from three origins: building standards that have been adopted by State agencies without change from national building standards, building standards adopted and adapted from national model codes, and building standards authorized by the California legislature constituting amendments not covered by national model code.
The CBSC is published as Title 24 of the California Code of Regulations and is made up of 13 parts, including the new Part 7 – California Wildland-Urban Interface Code (CWUIC).
CalFire provides guidance and resources in Building in the Wildland. Existing communities located in wildfire-prone areas need to take extra measures to improve public safely. There are many ways to prepare communities and properties for wildfire that include creating and maintaining adequate defensible space and hardening structures. Using building construction methods that are rated for the wildland, can help reduce the likelihood of building ignition. Protecting structures by selecting, locating, and maintaining vegetation and other combustible materials can reduce the chance of a structure ignition.
CalFire PowerPoint 2025 pdf: California Wildland-Urban Interface: Navigating New Part 7 of Title 24, California Building Standards Code. This course is approved by The American Institute of Architects (AIA) for 6 Learning Units and International Council Preferred Provider Program.