What Is AB 3074?
AB 3074 is a California law that creates Zone 0 — a mandatory ember-resistant 5-foot perimeter around homes in fire hazard severity zones. Signed by Governor Gavin Newsom in October 2020 and authored by then-California Assemblymember Laura Friedman, it amends Public Resources Code 4291 and is being phased into enforcement between 2025 and 2028.
Zone 0 must be ember-resistant: no combustible materials, no flammable plants, no wood mulch, no wood fences attaching to the structure within 5 feet. Enforcement is phased between 2025 and 2028.
The law was created in direct response to research from CAL FIRE, the National Fire Protection Association (NFPA), and the Insurance Institute for Business & Home Safety (IBHS) showing that embers — not direct flames — cause the majority of home losses during California wildfires.
For San Bernardino County homeowners, AB 3074 is the most significant change to defensible space rules in a generation. Understanding it now — before 2027 — is the difference between gradual planning and an emergency rush.
Why does Zone 0 matter for wildfire defense?
Embers Are the Real Threat
Embers — not direct flame contact — cause an estimated 60–80% of home losses during California wildfires, according to research from CAL FIRE, the National Fire Protection Association, and the Insurance Institute for Business & Home Safety (IBHS). A burning ember the size of a fingernail can travel a mile or more ahead of the fire front, land in dry mulch or against a wood fence, and ignite a structure long before flames arrive.
- Studies show 60–80% of home losses during wildfire result from ember intrusion, not direct flame contact
- Embers can travel a mile or more ahead of the main fire front
- Embers ignite vegetation, debris, and combustibles within feet of structures
- The first 5 feet around your home is where ember ignition most directly threatens the structure itself
What the Research Shows
Research from NFPA, IBHS, and CAL FIRE consistently shows ember-driven home ignition is the dominant loss mechanism. Without Zone 0 compliance, even properties with strong defensible space at 30+ feet remain vulnerable to ember-driven losses. Zone 0 closes the most dangerous gap in California's old defensible space framework.
Real-World Examples
The Camp Fire (2018), Tubbs Fire (2017), and the recent 2025 Eaton and Palisades Fires destroyed thousands of homes — many on properties with significant defensible space at distance, but combustible material right against the structure. The local lesson is the 2003 Old Fire and the 2020 El Dorado Fire, both of which produced massive ember casts across San Bernardino County.
What's the difference between Zone 0, Zone 1, and Zone 2?
PRC 4291 now defines three concentric zones around your home. Each has different rules.
Zone 0 (0–5 feet)
- Ember-resistant zone
- No combustible materials
- No flammable plants or wood mulch
- Hardscape only (gravel, pavers, stone, concrete)
- Most stringent requirements — AB 3074's primary contribution
Zone 1 (5–30 feet)
- Lean, clean, and green zone
- Maintained landscape allowed
- Vegetation must be spaced and pruned
- Drought-tolerant fire-resistant plants encouraged
- Existing PRC 4291 requirement
Zone 2 (30–100 feet)
- Reduced fuel zone
- Vegetation thinning required
- Spacing per slope and species
- Existing PRC 4291 requirement
See our defensible space service for full-property compliance and our Zone 0 hardening service for ember-resistant work specifically.
When Does AB 3074 Apply to You?
Geographic Application
- Very High Fire Hazard Severity Zones (VHFHSZ): subject to AB 3074
- High Fire Hazard Severity Zones in State Responsibility Areas: subject to AB 3074
- Properties outside designated fire hazard severity zones: generally not subject
Use CAL FIRE's online Fire Hazard Severity Zone map at egis.fire.ca.gov to confirm your property's designation. Most foothill and mountain properties in San Bernardino County fall inside one of these zones.
Enforcement Timeline
AB 3074 enforcement is phased by property type and fire hazard zone. The table below summarizes who is affected, what deadline applies, and what action makes sense to take now.
| Property Status | Fire Hazard Zone | Compliance Deadline | Action Recommended |
|---|---|---|---|
| New Construction | VHFHSZ | Certificate of Occupancy (current) | Build to Zone 0 standards from day one |
| New Construction | HFHSZ in SRA | Certificate of Occupancy (current) | Build to Zone 0 standards from day one |
| Existing Structure | VHFHSZ | Phased through 2027 | Begin compliance work now |
| Existing Structure | HFHSZ in SRA | Phased through 2028 | Begin compliance planning |
| Existing Structure | Outside FHSZ | Not subject | Best-practice voluntary compliance |
| Pre-Sale Property | Any FHSZ | AB 38 inspection required | Document compliance before listing |
Implementation timing has shifted during the regulatory process. Verify current deadlines for your jurisdiction at fire.ca.gov before making major decisions.
- 2025–2026: New construction in VHFHSZ must comply with Zone 0 at certificate of occupancy
- 2027: Existing structures in VHFHSZ must achieve Zone 0 compliance
- 2028: Existing structures in HFHSZ within State Responsibility Areas must achieve Zone 0 compliance
Implementation timing has shifted during the regulatory process. Verify current information with fire.ca.gov before making major decisions based on a specific date.
What is required in Zone 0 under AB 3074?
Materials That Must Be Removed
- Wood mulch and bark mulch
- Combustible groundcover plants
- Wood fences attached directly to structures within the 5-foot zone
- Combustible decking that connects to structures
- Wood piles, lumber, firewood
- Vegetation directly contacting the structure
- Combustible furniture, planters, decorations within 5 feet
- Combustible doormats and outdoor rugs
Materials That Are Allowed
- Gravel (preferred for most properties)
- Decomposed granite (DG)
- Concrete and concrete pavers
- Stone, brick, masonry pavers
- Bare soil
- Non-combustible hardscape generally
- Some succulent plants — with conditions and spacing requirements
Special Considerations
- Fences: wood fences attaching to the structure within 5 feet must be replaced with non-combustible material (metal, masonry, or fire-rated composite). Wood fences entirely outside the 5-foot zone are not affected.
- Decks: combustible decks that contact or attach to the structure within 5 feet require evaluation; many require replacement or upgraded materials.
- Vents and eaves: AB 3074 includes provisions for ember-resistant vents (1/8-inch metal mesh) on existing structures during phased compliance.
- Trees overhanging Zone 0: branches over the 5-foot zone may need pruning or tree removal depending on species and condition.
Get a Free Zone 0 Walkthrough
A vetted licensed San Bernardino County contractor will assess your first 5 feet and provide a written estimate. No obligation.
Free Zone 0 assessment
Vetted licensed contractors • Typically respond within 24 hours
What are common ways to comply with Zone 0?
Approach 1: Gravel Conversion
- Most common and lowest cost
- Replace all combustibles with crushed gravel or decomposed granite
- Industry-standard pricing typically a moderate range
- Quick to implement
- Maintenance-light long-term
Approach 2: Hardscape with Limited Plantings
- Pavers, stone, or concrete with carefully selected fire-resistant succulents
- Higher upfront cost
- More aesthetically appealing
- Requires ongoing maintenance to preserve plant fire-resistance characteristics
Approach 3: Comprehensive Fire-Resistant Landscape Design
- Full landscape redesign for both compliance and aesthetics
- Fire-resistant plant selection in adjacent Zone 1
- Smart irrigation, ember-resistant hardscape, professional installation
- Higher cost range, often combined with property value upgrades
- Best for properties planning to sell or seeking insurance discounts
How does AB 3074 affect home insurance?
Zone 0 Compliance and Insurance Discounts
- Under California Insurance Code Regulation 2644.9, insurers must offer rate considerations for properties implementing specific mitigation measures
- Zone 0 compliance is one of the qualifying mitigation measures
- Specific discounts vary by carrier
- Documentation typically required (before-and-after photos, written compliance reports)
Zone 0 and Non-Renewal
- Insurance carriers increasingly require documented mitigation for renewals in fire hazard zones
- Properties with documented Zone 0 work generally have better insurance options
- Some carriers will not renew without Zone 0 compliance regardless of statutory timeline
- See our Insurance Non-Renewal Help guide.
How should you prepare for AB 3074 enforcement now?
If 2027 Enforcement Applies to You
- Confirm your property's fire hazard severity zone designation at egis.fire.ca.gov
- Document current Zone 0 conditions with photos
- Get an on-site walkthrough from a vetted contractor
- Plan compliance work within budget — most homeowners benefit from spreading work over 12–18 months
- Maintain ongoing compliance as natural changes occur
If You're Building or Renovating
- Zone 0 compliance is required at certificate of occupancy starting 2025–2026
- Incorporate Zone 0 design into initial landscape planning
- Many builders now include Zone 0 specifications in standard plans
- Consult fire-resistant landscape designers for guidance
If You're Selling
- Zone 0 compliance can be a significant property differentiator
- Buyers in fire hazard zones increasingly weigh mitigation work
- Documentation suitable for AB 38 disclosure available from licensed contractors
How much does Zone 0 compliance cost?
- Basic gravel conversion in Zone 0: typically lower hundreds to a moderate range
- Hardscape with limited plantings: typically a moderate to higher range
- Comprehensive fire-resistant landscape design: significantly higher, depending on scope
- Free on-site estimates from vetted contractors typically standard
Free assistance is available through the Mountain Rim Fire Safe Council for qualifying mountain community residents — particularly in Forest Falls and surrounding mountain communities. Apply at firesafenow.org.
What are common misconceptions about AB 3074?
"Zone 0 means I can't have any plants near my house"
Some plants are acceptable, particularly succulents and well-spaced fire-resistant species. The requirement is no combustibles within 5 feet — vegetation evaluation is part of compliance assessment.
"I have until 2027, so I can wait"
Most homeowners benefit from spreading compliance work over time rather than rushing in 2027. Insurance carriers may require Zone 0 work earlier than statutory deadlines. Property sales (AB 38) accelerate timelines further.
"My fence is fine, it's outside the 5-foot zone"
Only the portion of a fence directly attaching to your structure within 5 feet is affected. Wood fences entirely outside that zone are not directly impacted by AB 3074.
"AB 3074 only applies to new construction"
False. Phased enforcement covers both new construction (2025–2026) and existing structures (2027–2028).
Frequently Asked Questions
Enforcement is phased. New construction in Very High Fire Hazard Severity Zones (VHFHSZ) must comply with Zone 0 at certificate of occupancy starting 2025–2026. Existing structures in VHFHSZ are required to comply by 2027. Existing structures in High Fire Hazard Severity Zones within State Responsibility Areas follow by 2028. Implementation timing has shifted during the regulatory process — verify current dates with CAL FIRE at fire.ca.gov.
Yes. CAL FIRE and local fire authorities will inspect for Zone 0 compliance during routine PRC 4291 defensible space inspections. Specific inspection schedules and frequency vary by jurisdiction.
The same enforcement mechanisms as PRC 4291 apply: notices, compliance windows, potential fines, and forced abatement. Documentation requirements may also affect insurance renewals and AB 38 real estate transactions.
Some elements (mulch removal, gravel installation under licensing thresholds) are DIY-friendly. Larger work, fence replacement, deck modification, or comprehensive landscape redesign typically benefits from licensed contractors. Anything over $1,000 in combined materials and labor requires a properly licensed contractor under California law.
Compliance responsibility typically falls on the property owner, not the tenant. Landlords with properties in fire hazard zones should plan Zone 0 compliance directly and coordinate access with tenants.
Many California insurance carriers already factor Zone 0 conditions into renewal decisions, regardless of statutory enforcement deadlines. Carriers can require Zone 0 work as a condition of coverage today.
Gravel conversion in Zone 0 — removing combustible mulch, plants, and materials within the first 5 feet, replacing with crushed gravel or decomposed granite. Industry-standard pricing typically falls in the lower hundreds to a moderate range for residential properties.
Official information is at fire.ca.gov, the California Office of the State Fire Marshal, and via your local fire authority. CAL FIRE has dedicated AB 3074 resources at fire.ca.gov/programs/communications/defensible-space-prc-4291.
What should you do next?
- Confirm your fire hazard severity zone designation at egis.fire.ca.gov
- Document current Zone 0 conditions with photos
- Get an on-site walkthrough from a vetted licensed contractor
- Plan and budget compliance work over 12–18 months
- Submit the form on this page or call (909) 515-0885
Related: FAQ · Services · CAL FIRE Notice Help · Zone 0 Compliance Guide