The county's defensible space duty starts at 30 feet. Nothing in force here regulates the first five.

Zone 0 in Sonoma County: 5,636 structures lost in 2017, and no local ember-resistant zone rule

Fact-checked August 20, 2026·Sources at the end of this article

Two sets of rules, and the one in force has no first five feet

Guides in this series usually separate a local rule that already binds you from a state rule that does not. Sonoma needs a different opening: the local rule does not exist.

In force now: Sonoma County Code Chapter 13A in the unincorporated county, a hazardous vegetation ordinance whose duty starts at 30 feet, and in one city, Santa Rosa City Code Chapter 9-30. Both are enforceable. Neither contains an ember-resistant zone.

Adopted, not yet in effect: the statewide regulation approved August 19, 2026, still awaiting Office of Administrative Law review and publication by the Secretary of State, so no compliance clock is running. Our timeline and enforcement guide follows that process. Sonoma is not among the at least twelve jurisdictions we have verified with a Zone 0 rule of their own in force; the register lists those, and the local ordinance tracker shows what each requires. Sonoma Valley Fire District's homeowner page, written after the vote, puts it the same way: the rules were approved on August 19, and "they are not law yet."

Where the statewide rule will reach in this county

The regulation runs on two legal tracks. In the State Responsibility Area (SRA, land where the state carries financial responsibility for wildfire protection) it reaches every hazard class, under Public Resources Code section 4291. In the Local Responsibility Area (LRA, city and district-protected land) it reaches only mapped Very High Fire Hazard Severity Zones, under Government Code section 51182. A Moderate-zone house in the SRA is inside the rule; a High-zone house in a city is outside it. The county describes the same split, noting that its three jurisdictional areas carry different defensible space regulations.

Whether the LRA track touches your parcel depends on a map your own fire district adopts, since "local fire districts must adopt these maps per Government Codes 51179 and 51177(e)." Adoption is uneven.

Windsor is the case worth stopping on. The Town publishes that "no properties within Windsor are designated Very High FHSZ," all of it having been designated Moderate "in response to the Tubbs Fire that occurred in October 2017 and the Kincade Fire." Windsor is LRA, so on today's map no parcel there carries the designation that triggers the state rule. That is not a permanent exemption: the Town says it may recommend upgrading severity if justified. Windsor lost homes in Tubbs, and the hazard map and the legal trigger are separate questions. Ask the Town and Sonoma County Fire District, and place your parcel with our address lookup walkthrough.

The strongest evidence: a fire marshal's own list of what he can cite

A negative finding is only as good as its test. Ours is a document Sonoma Valley Fire District's Fire Prevention Bureau wrote for its own inspectors in 2026, an "Inspection Area Violation Standards Comparison" tabulating every citable defensible space violation across five parcel and area combinations, including the one covering the City of Sonoma. Its authorities line names Chapter 13A as amended in December 2025, Public Resources Code section 4291, 14 CCR section 1299 and the 2025 California WUI Code. We re-downloaded and re-searched it on August 20, 2026. A full-text search returns zero occurrences of "Zone 0," "Zone Zero," "five feet," "5 feet," "5 ft," "fence," "noncombustible," "non-combustible" or "mulch." It has two zones, headed "ZONE 1 (0-30 ft from structure)" and "ZONE 2 (30-100 ft from structure)." There is no zone before Zone 1.

Characterize it accurately: an internal enforcement chart, not a regulation, binding nobody. Its value is that it is the enumerated list of what a Sonoma fire marshal can actually write you up for, compiled by the person who writes the citations, and there is no ember zone on it. The county's advisory material agrees. The Home Resilience Guide treats the first five feet as advice, saying "noncombustible rock, gravel, concrete and pavers should be used in this zone." Note the "should."

What Chapter 13A requires, and why nothing new was added

In the unincorporated county the duty on an improved parcel is a list of ten numbered items. It opens with "Maintain a thirty-foot defensible space around all structures," with grass cut to six inches or less and branches limbed up six feet, and allows more clearance "outward to one hundred feet (100') from all structures" depending on slope and fuel. The rest covers roadside and chimney clearance, spark arresters, roof debris, address numbers and dead vegetation. The list ends at item (10), and nothing in it touches the first five feet, mulch, or fences. On unimproved parcels the duty is narrower still, a ten-foot strip around structures and road frontage.

The county refreshed this code recently and added no ember zone. It adopted its 2025 building and fire code update on December 9, 2025, effective January 8, 2026, and Sonoma Valley's fire marshal summarized the Chapter 13A changes as "limited to three categories: correcting typographical errors, expanding the definition of authorized enforcement representatives, and broadening enforcement discretion." The same board packet attributes the thin cycle to state law, "California SB 1255 (2024), which significantly constrained the ability of local jurisdictions to amend the California Building Standards Code." The one new local wildfire provision is a fire separation distance table for SRA construction: a new-building standard, not a retrofit duty.

Enforcement is real even though the substance stops short of the house. Permit Sonoma and the districts run "approximately 4,000+ defensible space inspections" a year, and a Windsor citation "carries with it a fine of up to $500 per day." None of it is a fence penalty.

Santa Rosa: the ordinance that goes further, and the question underneath it

Santa Rosa City Code Chapter 9-30, added by Ordinance ORD-2023-016 and adopted December 12, 2023, is the only Sonoma city ordinance we found reaching beyond state defensible space law. State law reaches only WUI properties also mapped Very High, while "the ordinance requires defensible space to be maintained on ALL properties in the WUI, not just those identified by the State." Its closest thing to a Zone 0 item is a mulch clause, and it is a 30-foot rule. Section 9-30.060(3) bans mulch within 30 feet of a structure in the WUI Fire Area where "the mulch is fibrous and stringy in nature" or where it "is dyed and based on its chemically altered composition promotes the spread of fire as determined by the Fire Chief or designee." Two categories, out to 30 feet: ordinary bark mulch is not banned, and the chapter says nothing about the first five feet. A full-text search returns no occurrence of "Zone 0," "five feet," "5 feet" or "fence."

One open question sits underneath it, and it is the most consequential thing a Santa Rosa homeowner can ask. Chapter 9-30 incorporates "Title 14, Section 1299. 3" by reference and applies it to every WUI Fire Area parcel, including LRA parcels the state rule would not reach on its own. The statewide Zone 0 provisions for the SRA are being added at 14 CCR section 1299.03. Whether that local reference is static, frozen to the 2023 text, or dynamic, moving with the state regulation, is a matter of local code construction no source we loaded answers. Do not assume Zone 0 switches itself on citywide in the Santa Rosa WUI; put it to the Fire Marshal, and see our open questions page for others like it. The city is also redrawing that WUI area, with a first reading on May 12, 2026 and a second reading scheduled June 2, 2026 that its legislative file does not record as taken. We will not tell you it passed, and we will not give you an effective date.

The loss record, and the gap the two tracks leave

The 2023 Community Wildfire Protection Plan records that the 2017 Sonoma Complex fires "caused 22 confirmed fatalities, and destroyed 5,636 structures and damaging another 317," and that the 2019 Kincade Fire "burned over 77,000 acres; 374 structures were lost in that fire and 60 were damaged." The Tubbs breakdown speaks directly to how Zone 0 is scoped.

In the Tubbs Fire, 3,708 structures were lost in the following FHSZs: Urban Unzoned (areas outside of SRA): 1984 structures, 54%; Moderate: 519 structures, 14%; High: 782 structures, 21%; Very High: 423 structures, 11%.

Sonoma County Community Wildfire Protection Plan 2023 Update, using the hazard classes as mapped at the time

Set that against the two tracks. On the face of these figures, a majority of Tubbs structure losses, the 54 percent recorded as "Urban Unzoned (areas outside of SRA)," fell in territory the LRA track would not reach unless mapped Very High. We will not turn that into a tidy percentage the rule "would miss": the table does not split SRA from LRA inside the other rows, and the 2025 update mapped Moderate and High in the LRA for the first time. The gap is visible without arithmetic.

One county page tells residents something we could not support

Permit Sonoma's Wildfire Resilient Communities page, re-verified live on August 20, 2026, tells residents that "beginning in early 2026, the California Building Code will require a non-combustible 'Zone 0' (typically five feet) around homes in high fire hazard severity zones."

Do not act on that sentence. Zone 0 is a Board of Forestry defensible space regulation under Public Resources Code section 4291 and Government Code section 51182, not a Building Code provision. The statewide package was adopted August 19, 2026 and is not yet effective, so nothing took effect under it in early 2026. And in the LRA it reaches Very High zones only, not high hazard zones generally. One check we have not closed, listed below, is why we call the sentence unsupported rather than flatly wrong. We report it because Sonoma residents are being sent to that page.

The money, and the dates attached to it

Sonoma's homeowner assistance was built largely on federal grants and a county financing program, and both are closing. Read the dates rather than the headings.

• Curbside chipper: open. The page reads "Accepting Reservations for Chipper Program 2026." Free chipping for properties "located in the unincorporated areas of Sonoma County," up to two hours with pre-approval for a second visit. Limbs no more than 10 feet, piles no more than 3 feet, and "no construction-type wood (fence posts, 2x4s, etc.)." Two catches: requests have "gone up significantly" and the county may suspend applications, and chips are "blown back onto the property" rather than removed. Chips are combustible mulch, so do not let them settle against the house.
• SoCo Adapts assessments: free, and time-limited. Inspectors give "a no cost defensible space assessment of vegetation and combustible material within 100 feet of buildings and within 10ft of roadways," and these "are not part of a code enforcement program." Two published dates mean different things: the assessment window runs "April – August 2026," while September 30, 2026 is the "End of federally funded wildfire mitigation activities." Do not assume you have until September 30 to book. Phone (707) 565-8575.
• The $10,000 implementation rebate: discontinued. Permit Sonoma's page carries the heading "Phase 2: Implementation (Discontinued)," citing delays in FEMA funding, though the county's wording is not uniform, saying "pausing" in one paragraph and "discontinuing" in another. Sonoma County Fire District's page still advertises "a rebate of approximately $10,000 per parcel." Prefer the administering agency, and call before spending in reliance on it.
• SCEIP financing: residential side closed. The residential program "is ending on March 1, 2026," with "no new residential applications… accepted after Jan. 12, 2026," existing contracts unaffected and the commercial portion continuing. Permit Sonoma's resources page still lists it for residential projects with no closure notice.

Nobody local pays for fence work. Not one Sonoma county, city, district or nonprofit program we loaded names fence replacement, gates, or noncombustible ground cover in the first five feet as an eligible item, and Fire Safe Sonoma's grants page is addressed to community groups rather than homeowners. The statewide door worth watching is the Safe Homes grant program created by AB 888, the California Safe Homes Act, effective January 1, 2026 and written to fund home hardening including mitigation within five feet of homes. Amounts have not been determined and we could not confirm the portal is open, so watch for it at the California Department of Insurance rather than budgeting against it. Our guide to who pays tracks this statewide.

Claims we could not verify

• The codified, in-force text of Chapter 13A. Municode returns an empty shell to automated fetchers and the county's other mirror timed out. Our clauses come from a county-hosted attachment headed "ORDINANCE NO. ( )", unnumbered and unsigned, corroborated by the December 2025 amending ordinance, the Sonoma Valley chart and the 2023 CWPP. All four agree there is no Zone 0 provision.
• Whether the 2025 California Wildland-Urban Interface Code contains any 0 to 5 foot noncombustible requirement. We did not read Title 24 Part 7. This is the check that would decide whether Permit Sonoma's Building Code sentence is defensible, and until it is closed we call that sentence unsupported rather than wrong.
• Whether Santa Rosa's reference to 14 CCR section 1299.3 is static or dynamic, and whether its WUI map ordinance passed the June 2, 2026 second reading. The record shows only the May 12 first reading, final action blank.
• The contents of Sonoma County Fire District Ordinance 2025-01. Both posted PDFs are image scans with no text layer. The title is verified; the text is not.
• Whether the City of Sonoma adopted its FHSZ ordinance, and whether the Board of Supervisors adopted one for unincorporated LRA. Neither was found.
• Sonoma SRA acreage, and the current number of local fire agencies. The CWPP acreage table extracts with scrambled columns, so we publish no county figure, and its count of 21 agencies is dated "as of 2023" with consolidation under way.
• Vote tallies, a Petaluma chipper program and a Healdsburg assessment program. No tally was verified for any ordinance here, and the other two appear in site navigation only, so we list neither as open.

What this means for you

• Nothing in force in Sonoma County requires you to replace a wood fence. If someone says otherwise, ask which ordinance section says so, and read it before you sign.
• Book the free assessment this month, not next. The published SoCo Adapts window closes at the end of August 2026 even though federal funding runs to September 30. Call (707) 565-8575.
• Do not budget against the $10,000 rebate, whatever a district page still says.
• Doing the work anyway? Sequence it. Walk the first five feet with our Zone 0 self-assessment, work the Zone 0 checklist, and read what the adopted rule asks of fences in our fence requirements guide and our explainer on the five-foot transition.
• Buy the material, not the label. Aluminum, steel, wrought iron, chain link, masonry, concrete and stone are the families to price; our guide to noncombustible fence materials explains the test behind them.

How often CAL FIRE inspects here

CAL FIRE has 611 parcels in Sonoma County in its defensible space inspection program in July 2026, the month the dashboard is currently reporting. Of the 590 inspected, 462 were compliant, which is 78 percent. 9 properties have already been found non-compliant more than once.

Two things this does not tell you. These counts cover inspections by CAL FIRE and Contract Counties inside the State Responsibility Area only, so work done by local fire agencies in the Local Responsibility Area is absent entirely. And none of these inspections is checking Zone 0: they are inspections against the defensible space rules in force today, which reach from the structure out to one hundred feet and contain no ember-resistant zone requirement. See the full inspection figures and what they mean, read from CAL FIRE's public dashboard on August 20, 2026.