Investigation

How local Zone 0 rules actually spread in California

Fact-checked August 24, 2026·Sources at the end of this article

What we thought was happening

We built the register one jurisdiction at a time, and for months the picture it produced was of scattered local initiative: a fire district here, a city council there, each responding to its own fires and its own politics. That is how the coverage describes it too, when it describes it at all.

On August 24, 2026 the register went from twenty to twenty-six entries in a single day. Not one of those six adopted anything that day. What changed is that we stopped searching for the names of cities and started searching for the operative sentences, and the moment we did, the rules stopped arriving one at a time and started arriving in families.

The Riverside family: one fence rule, fourteen Riverside jurisdictions, and the county went eleventh

Riverside County's version lives at Section 604.11 of the wildland-urban interface code, added locally in three short parts. Its scope clause covers fences and gates within five feet of a building, which the text itself labels "(Zone 0)." Then:

"604.11.2 New fencing. New fencing and gates shall be constructed of a non-combustible material."

"604.11.3 Existing fencing. Fencing installed prior to January 1, 2026, may remain. Exception: The entire fencing not parallel and within 5 feet of the Building, including gates within the fencing, shall be constructed of a non-combustible material when any portion of the existing fencing within 5 feet is being replaced."

That exception reverses the state's own rule, which expressly permits combustible repairs to an existing combustible fence. And it is not one city's drafting quirk. The identical text is in force in:

• Unincorporated Riverside County, Ordinance 787 as amended through 787.11, effective January 7, 2026, which is the source of the language
• Moreno Valley, Ordinance 1033, adopted November 4, 2025
• Beaumont, Ordinance 1190, adopted November 4, 2025, the same day
• Jurupa Valley, Ordinance 2025-24, adopted November 6, 2025
• Wildomar, Ordinance 258, adopted November 12, 2025
• Banning, Ordinance 1613, adopted November 12, 2025, the same day
• Temecula, Ordinance 2025-14, adopted November 18, 2025
• Lake Elsinore, Ordinance 1521, adopted November 18, 2025
• Indio, Ordinance 1824, adopted November 19, 2025
• Menifee, Ordinance 2025-425, passed November 19, 2025
• Norco, Ordinance 1135, adopted November 19, 2025
• La Quinta, Ordinance 627, adopted December 16, 2025, inside a whole-code adoption rather than a fire ordinance
• Palm Desert, Ordinance 1439, adopted January 8, 2026
• Indian Wells, Ordinance 769, adopted February 5, 2026

Read the dates, because they carry the argument. Sort all fourteen by adoption and the county comes eleventh. Ten cities adopted this fence rule before the county adopted it: Beaumont and Moreno Valley on the same day, November 4, 2025, then Jurupa Valley on the 6th, Wildomar and Banning on the 12th, Temecula and Lake Elsinore on the 18th, and Indio, Menifee and Norco on the 19th. Ordinance 787.11, which this page identifies as the source of the language, was not adopted until December 9 and took effect on January 7, 2026. A rule cannot spread outward from an ordinance that has not been adopted yet, so something else was in circulation, and a county fire department's model text moving through a code cycle with each council taking its turn is what that looks like. Two of the ordinances say so almost explicitly: Moreno Valley's and Norco's both add "Riverside County Fire Department Guidelines" as a fifth item to the four state laws that the model code's own Section 604.3 already requires vegetation to comply with. Moreno Valley's advisory notice goes further, stating that the department "has local Zone 0 requirements currently in effect for new buildings and additions to existing buildings." The county page carries the full text. Every city we had named as a lead has now been read from its adopted or codified text, and every one of them had adopted earlier than we assumed.

The San Diego family, which is three years older than the statewide rule

San Diego County's version is a different sentence at a different number, and it is considerably older. The County of San Diego 2023 Consolidated Fire Code, eighth edition, effective April 13, 2023, which by its own description compiles "the County amendments to the 2022 California Fire Code and the ordinances of the unincorporated County fire protection districts," contains Section 4907.9 "Home Ignition Zones" and under it:

"Sec. 4907.9.1 Zone 0 'Immediate Zone' 0-5'. Meaning from exterior wall surface or patio, deck or attachment to building or structure extending 5 feet on a horizontal plane. This zone shall be constructed of continuous hardscape or non-combustible materials. Removal of combustible materials surrounding the exterior wall area and maintaining area free and clear of combustible materials. The use of mulch and other combustible materials shall be prohibited."

That is a Zone 0 rule in force in unincorporated San Diego County more than three years before the Board of Forestry adopted the statewide version. The same sentence appears in the separate ordinances of the Rancho Santa Fe Fire Protection District, effective January 1, 2026, and the Valley Center Fire Protection District, Ordinance 2025-68, finally adopted on October 16, 2025 by a five to nothing roll call. It also appears, word for word, in the City of Santee's separately added Section 603.5.

The dates here run backwards from the obvious story. The county's consolidated 2026 code had its first reading on February 10, 2026, but Valley Center adopted in October 2025 and Rancho Santa Fe was in force on January 1, 2026. The consolidation gathered up language that was already circulating; it did not originate it. The county page has the full account.

A warning if you go looking yourself: the section number is not the fingerprint

We found the Riverside family by searching for "604.11," which worked because every member kept the number. That method then nearly misled us. The 2025 code cycle renumbered San Diego's provision from Section 4907.9.1 to Section 604.12.1, so the same words now sit under a different number, and Rancho Santa Fe's own code-comparison table records the move. Meanwhile Rancho Santa Fe's Section 604.11 is not a fence rule at all; it is "Eucalyptus forests and oak woodlands."

Search the sentence, not the number. A model ordinance keeps its wording across adopters far more reliably than it keeps its numbering across code cycles.

Doing that turned up the thing we had wrong: Riverside did not write this rule

Added August 29, 2026. Everything above calls Section 604.11 a Riverside County model, because that is where we kept finding it. Then we read Ventura County Fire Protection District Ordinance 34 in full, in the packet the City of Port Hueneme's council was given, and found the same rule sitting under the same number, in the same three subsections, with the same titles. Set the operative exception side by side. Ventura first:

"The entire fencing not parallel and within 5 feet of the Building, including gates within the fencing, shall be constructed of a non-combustible material when any portion of the existing fencing within 5 feet is being replaced. Fencing beyond 5 feet from the Building is not required to be replaced with non-combustible material."

VCFPD Ordinance No. 34, Article 4, Section 604.11.3

Now Riverside, from Lake Elsinore's Municipal Code Chapter 15.58:

"The entire fencing not parallel and within 5 feet of the Building, including gates within the fencing, shall be constructed of a non-combustible material when any portion of the existing fencing within 5 feet is being replaced. Fencing beyond 5 feet from the Building is not required to be replaced with non-combustible material."

City of Lake Elsinore Municipal Code Chapter 15.58, Section 604.11.3, Ordinance 1521

Those are the same sentence. We compared them character by character after normalising whitespace and curly quotes, and there is no difference at all.

And Ventura's is the older one, by three years. Riverside's version grandfathers fencing installed before January 1, 2026. Ventura's grandfathers fencing installed before January 1, 2023, and Port Hueneme's staff report states that Section 604.11 has "been in effect within the Fire District since January 1, 2023." The date is not decorative: it is the hinge the whole rule turns on, and someone moved it forward three years.

The differences are small and they are the tell. Ventura scopes the rule to properties "in the WUI area"; Riverside scopes it to "an applicable Fire Hazard Severity Zone" as required by its Chapter 6. Ventura dates its new-fencing clause, requiring noncombustible material for fencing "installed on or after January 1, 2023"; Riverside drops the date and simply requires it of new fencing. Those are the edits of someone adapting a document to a different county, not of someone writing one.

What we are not telling you is that Riverside copied Ventura. Two documents sharing a sentence prove a common source, not a direction of travel, and both could descend from something we have not found. What the identity does establish is that this is not a Riverside County invention that spread to Riverside County cities. The same text was already law in another county, under another fire district, three years earlier. Whatever is circulating is circulating between county fire agencies, not out from one of them, and it is older than the statewide rule that is supposed to be introducing California to Zone 0.

And in San Diego County, the model ordinance is published with its blanks still in it

Added August 29, 2026. Everything on this page argues that these rules travel as model text rather than as thirty separate ideas. San Diego County supplies the least deniable version of that. Its 2026 Consolidated Fire Code, ninth edition, effective January 1, 2026, is a single document written for twelve fire protection districts to adopt, and its findings section is a fill-in template. The phrase "Insert your fire protection district" appears in it sixteen times:

"As required by Health and Safety Code section 17958 the Insert your fire protection district Board of Directors does herewith make express findings that amendments to the California Building Standards Code are necessary for the protection of the public health, safety and welfare due certain climatic, topographic or geological features existing in the County of San Diego."

County of San Diego 2026 Consolidated Fire Code, ninth edition, findings for revision. The emphasis is ours; the placeholder is theirs.

That is not an embarrassment and we are not presenting it as one. It is a template because it is meant to be a template: one county code office drafting findings that twelve boards will adopt, each inserting its own name. It just happens to be the clearest possible evidence for what this page has been arguing from adoption dates elsewhere. In Riverside you have to infer the shared source from identical sentences and a calendar. In San Diego the shared source is printed with the seams showing.

A third family, in Marin, and one town that forgot to fill in the blank

Added August 30, 2026. Riverside and San Diego are the two families this page was built on. Sweeping northern California turned up a third, and it behaves differently enough to be worth knowing about.

Marin County, the Town of Fairfax and the Town of Corte Madera share drafting that is plainly one document: an added Section 613.3 defining an "Exterior Wildfire Protection System", an amended Section 603.3.1 requiring a vegetation management plan to delineate "Zone 0 (0'-5'), Zone 1 (5'-30'), Zone 2 (30'-100') fuel management zones from all structures and Zone 3 (10' on either side of the road or driveway)", and an added Section 604.6 headed "Fire Hazard Reduction".

The opening sentence of that last section is identical in all three, and it contains one slot. Here is how each filled it:

Corte Madera's codified municipal code still has the bracket in it. "AHJ" is "authority having jurisdiction", and that is a drafting placeholder the adopting town was meant to replace with its own name. It is the same evidence as San Diego publishing a code that says "Insert your fire protection district" sixteen times, and in one way it is better: San Diego is openly distributing a template, whereas here somebody adopted one and enacted the blank.

We are not printing this to embarrass a town of ten thousand people. We are printing it because this page has spent a lot of words arguing from identical sentences and adoption calendars that these rules travel as model text, and an unfilled placeholder in an enacted code is that argument without any inference in it at all.

The part that matters if you live there: this family names Zone 0 and never regulates it

The Riverside and San Diego families impose Zone 0 duties. This one does not. Across all three Marin codes, "Zone 0" appears exactly twice and in only two roles: in the list of zones a vegetation management plan has to draw, and in the definition of the area an exterior sprinkler system is designed to wet. Neither prohibits anything in the first five feet. The word "fence" does not appear anywhere in the wildland-urban interface chapter of any of the three.

So a homeowner in Marin who searches the local code, finds "Zone 0", and concludes a five-foot rule binds their fence has reached the wrong conclusion from a real document. That is a specific way to be misled, it is easy to do, and it is why none of these three is on our register.

None of these rules explains itself, and the law is why that is worth noticing

Added August 29, 2026. A local agency cannot be stricter than the state building code because it feels like it. It has to make express findings that local climatic, geological or topographical conditions make the stricter standard reasonably necessary, and file them. Two statutes carry the requirement: Health and Safety Code section 13869.7 for fire protection districts, and section 17958.7 for cities and counties. Every fence rule on this page rests on a findings document somewhere.

We have now read three of them, covering the same fence rule under both statutes:

We counted over the findings sections themselves, not the whole documents, which do of course discuss fences later where they set out the code amendments.

The point is not that these findings are thin. They are the opposite of thin. Riverside's name two named faults and La Quinta's works through the metallurgy of household wiring. They are detailed, locally researched, and specific. They simply never arrive at the subject of the rule this site exists to explain. Nothing in any of the three says why a combustible fence within five feet of a house is a hazard, how a fence carries fire to a structure, or where the five feet comes from.

What we are not saying. We are not saying any of these ordinances is invalid. Findings are written to support a whole package of amendments, general findings can lawfully support a specific standard, and no one requires a paragraph per section. A homeowner should not read this as a reason to ignore a rule that binds them.

What it does mean is more modest and more useful. If you go looking for the reasoning behind the five-foot fence rule expecting to find the fire-behaviour case in the legal record, it is not there.

It is one document over. Ventura County Fire Department publishes Guideline 421, "Combustible Fencing in Defensible Space Zones," which reproduces Section 604.11 and then says plainly what the findings resolution never does: "Review of previous wildland fires, and newer laboratory testing, has shown that combustible fences are a contributing factor in fire spread to buildings." It cites IBHS, UCANR and NIST, including NIST's August 2022 study of residential fences and mulch beds. Ventura's fence rule took effect the following January.

So the reasoning is real, it is written down, and it is datable. It simply lives in a fire department's guidance rather than in the instrument the statute makes the rule's foundation. That is the gap worth knowing about: not an absence of thinking, but a separation between where the thinking is recorded and where the law says the justification goes. The Ventura County page quotes the guideline in full.

Where the rule is not, and what the empty space explains

Added August 30, 2026, and extended through the day. Everything above is about where these rules are. We went looking for where they are not, because a pattern you can only see in its hits is not really a pattern. We have now read ninety-four California cities this way: every one that publishes on the same code platform in the counties below, plus a spread of fire-exposed cities elsewhere in the state. For each we read the building, construction, fire, wildland, safety and health titles and searched the codified text.

One of the ninety-four had a Zone 0 rule in its own municipal code. It was Banning, and it is now on the register. The table below is the first three counties we did, and it is representative of all of them.

Every one of those codes is current through 2026, so this is not a case of reading stale volumes. Three more were attempted and returned no chapter matching our filter, so they are left out of the count rather than reported as negatives: Duarte, Tehachapi and Ridgecrest. The City of Orange does not publish on this platform at all.

The rest of the ninety-four, beyond the three counties tabled above, were: Blythe, Coachella, Eastvale, Hemet, Perris and the City of Riverside; Pasadena, Long Beach, Oakland, Richmond, San Rafael, Novato, Vallejo, Redding, Truckee, Portola Valley, Los Gatos, Saratoga, Lafayette, Moraga and Orinda; Carpinteria, Sonora, Colfax, Rocklin, Lincoln, Citrus Heights, Windsor, Willits, Weed, Yreka, Dunsmuir, Mammoth Lakes, Scotts Valley and Morgan Hill; Oceanside, San Marcos, Del Mar, La Mesa, National City, San Jose, Los Altos, Hillsborough, San Anselmo, Corte Madera, Tiburon, Pacifica, El Cerrito, Belmont and Milpitas; and Anderson, Arroyo Grande, Bishop, Chino, Clayton, Corning, El Paso de Robles, Fontana, Hollister, Ione, Lancaster, Monte Sereno, Portola and Rialto. We are listing them rather than summarising them so that anyone who wants to check our work knows exactly which codes we opened.

These are not low-risk places. Calabasas, Agoura Hills, Rancho Palos Verdes and Sierra Madre are among the most wildfire-exposed cities in California. Banning, which does have the rule, is not obviously more exposed than any of them. So whatever decides which cities have a local Zone 0 rule, it is not how much fire risk the city faces.

What it actually tracks is who writes your fire code

All eight Orange County cities above are served by the Orange County Fire Authority, a joint powers authority covering twenty-three of that county's thirty-four cities. The one Orange County city on our register is Laguna Beach, and Laguna Beach is one of the ten cities in that county that run their own municipal fire department. We had established that fact on the Orange County page for an unrelated reason, and it turns out to be the whole explanation.

Line the counties up and it holds. Riverside County Fire, the Ventura County Fire Protection District and San Diego County's twelve-district code office each produced model text, and the cities they serve carry it, in some cases identically. Los Angeles County, Orange County and San Bernardino County cities are served by agencies that have not produced such text, and they carry nothing at all.

One thing we got too enthusiastic about, corrected the same day. We first wrote that a city has its own rule either because its county agency wrote model text or because it runs its own fire department. The second half was reasoned from one case, so we tested it, and it does not hold. We read fifteen more cities the same way, all current through 2026: Pasadena, Long Beach, Oakland, Richmond, San Rafael, Novato, Vallejo, Redding, Truckee, Portola Valley, Los Gatos, Saratoga, Lafayette, Moraga and Orinda. Nothing in any of them. Oakland, Pasadena and Long Beach all run their own municipal fire departments, and Oakland's hills carry one of the most consequential wildfire histories in California.

So running your own fire department permits a city to write a Zone 0 rule; it does not predict that it will. Laguna Beach is an exception rather than a pattern. What survives is the first half, and it survives more strongly for having the second removed: what predicts a local Zone 0 rule is whether the county fire agency produced model text. Ninety-four cities read, one of them had the rule, and that one was Banning.

Riverside tests the same idea without leaving the county

Comparing counties is a weak way to argue this, because counties differ in climate, hazard mapping, politics and when they adopt a code cycle, and any of those could be doing the work instead of the fire agency. Riverside removes all of it: one county, one hazard map, one set of state deadlines, and two kinds of city inside it.

The Riverside County Fire Department serves the unincorporated county plus its contract partner cities. Nine cities in the county run their own fire departments outside that system: Blythe, Calimesa, Canyon Lake, Cathedral City, Corona, Hemet, Murrieta, Palm Springs and Riverside.

Section 604.11 is in force in fourteen places in this county, and not one of them is on that list of nine. We have now read eight of the nine from their codified text, and none has a Zone 0 rule of its own: Blythe, Hemet, the City of Riverside, Palm Springs, Corona, Murrieta, Canyon Lake and Cathedral City.

Corona is the case that settles it, and we read every word of it. Corona adopted the 2025 Wildland-Urban Interface Code as Chapter 15.25 of its municipal code by Ordinance 3421 in 2025. We walked all sixteen sections of that chapter. It amends the title, the code adoption, the administration, the definitions, the hazard-zone designation, the water supply, the fire protection plan and the penalties. It amends Section 604.3. It never adds Section 604.11.

And look at what it did to 604.3, because this is the part that is hard to explain any other way. Corona rewrote it to require hazardous vegetation to be maintained under four state laws plus a fifth item: "City of Corona Vegetation Management Guidelines." Moreno Valley and Norco made exactly the same structural edit to exactly the same section, and their fifth item reads "Riverside County Fire Department Guidelines." Same model code, same amendment, same slot, and the name in it is whichever fire agency the city answers to. Corona's own department writes its guidelines, so Corona named itself, and Corona did not take the fence rule.

Palm Springs makes the same point more briefly: it adopted the 2025 code with all appendices and did not add the fence section either.

Murrieta is the other exhaustive one. Its fire code chapter runs to seventy-seven sections and we read every one of them, some seven hundred thousand words of code between them. Two came back as bot challenges on the first pass and were retried; they turned out to be about sprinkler supervision and elevators. Nothing in any of the seventy-seven touches fencing in the first five feet.

Canyon Lake took the same exhaustive treatment as Murrieta: seventy-nine sections of its fire code chapter, every one read, nothing about fencing in the first five feet. Cathedral City answers the question a different way. Its codified fire code is still the 2022 edition. It contains no Section 604.11, and the word "wildland" does not appear in it at all, which is what you would expect of a city that has not yet moved to the code cycle the fence rule lives in.

One of the nine is left. Calimesa publishes on a host that refuses automated requests, and the only archived copy we can reach is from 2022, three years before the cycle in question, so it would not answer anything. Eight out of nine, and we are saying which one is missing rather than rounding up to a clean number.

Put the two halves together and the county answers the question on its own. Section 604.11 is in force in fourteen places here and every one of them is served by the Riverside County Fire Department. Eight cities run their own fire departments and not one of them has the rule, including two that adopted the very same 2025 code and one that made the identical amendment to the neighboring section. Same county, same maps, same statutory deadlines, same model code. The variable that moves is which fire department writes the code.

We tested our own search against rules we already knew about, and it misses some

A sweep is only worth as much as its ability to find things. So we pointed the same search at a dozen entries already on our register that publish on the same platform, where we know the answer in advance, and counted.

Seven found, four missed. The four it missed have something in common: they are the older rules, written before the 2025 code cycle and before "Zone 0" became the standard phrase. Butte County's chapter, as we have noted elsewhere, never uses the word "fence" at all. Paradise wrote its chapter after the Camp Fire in 2019. Our first search looked for the two model sentence families, for the section numbers those families use, and for the words "Zone 0" beside a noncombustible or hardscape term, and a rule that describes the first five feet in its own words slipped straight past it.

So we widened the search and ran everything again. It now also looks for "ember-resistant zone", for embers mentioned near a five-foot distance, for a five-foot distance near a noncombustible or ignition-resistant term in either order, and for citations of Public Resources Code section 4291. Against the same test set it now finds all of them, including the four it had missed. Re-run across every city, the answer did not change: one hit, Banning, and nothing anywhere else.

Two of those cities are worth naming for what they show. Moraga and Orinda both came back empty, and the fire district that serves them, Moraga-Orinda, is on our register with a Zone 0 rule of its own. Two cities with no Zone 0 rule in their municipal codes, inside a district that has one. That is the whole argument of this page happening inside a single county, and it is why searching your city's code is the wrong place to start.

Read the ninety-four accordingly. It is good evidence that these cities have not written Zone 0 rules of their own, in either the modern or the older idiom. It is not a claim that no rule reaches those addresses, because as Moraga and Orinda show, the rule that reaches you may belong to your fire district rather than your city. We would rather publish the miss rate and the correction than imply a completeness we have not earned.

A second note for anyone repeating this. Long Beach flagged twice on the phrase "not parallel" and neither was a fence: one is its street-numbering chapter describing "a curved street or street not parallel either to the base line or meridian", the other its earthquake retrofit chapter on "floor joists not parallel to foundations". We only found that by opening both. A three-word fragment is not a fingerprint. The whole sentence is.

The practical version, which is the reason to publish this: if you want to know whether a local Zone 0 rule reaches your address, the useful question is not how dangerous your neighborhood looks or even what your city council has done. It is who runs your fire department. If that is a county agency or a regional authority, look at what the agency has adopted rather than at your city's municipal code, because your city may never have written one. If your city runs its own department, its own code is where to look.

We are calling that a strong correlation and not a proof. Thirty cities is a sweep rather than a census, we read the fire and building titles rather than every chapter of every code, and one county fire agency could adopt model text next year and move a dozen cities at once. The advice survives either way.

The step almost nobody mentions: your council still has to vote

A fire district cannot simply impose building standards on the cities inside it. Health and Safety Code section 13869.7(a) lets a district adopt building standards more stringent than the state's, and subdivision (c) sets the price:

"The legislative body of the city, county, or city and county, may ratify, modify, or deny an adopted ordinance… No ordinance adopted by the district shall be effective until ratification by the city, county, or city and county where the ordinance will apply."

The districts know it and write it into their own text. Ventura County Fire Protection District's Ordinance 34, adopted October 14, 2025, provides that its provisions "shall apply upon the effective date of this Ordinance or upon the date of said ratification or adoption by the County or any city, whichever is later." The County of San Diego's 2023 Consolidated Fire Code recites the same rule from its side.

The clearest statement of it we have found belongs to the Moraga-Orinda Fire District, which adopted its own 2025 WUI code as Ordinance 26-02 on January 21, 2026 and published this with the notice of adoption:

"These Ordinances shall take effect thirty-five (30) days after their adoption; however, the building standards in these Ordinances shall not take effect within any municipality located in the District until ratified by the governing body of that municipality. The building standards in these Ordinances shall not take effect within the unincorporated areas of the District until ratified by the Board of Supervisors of the County of Contra Costa."

Moraga-Orinda Fire Protection District, Notice of Adoptions, issued January 28, 2026.

Note what the second sentence does. It is not only cities that have to vote: the unincorporated part of a district waits on the county board. So a district ordinance can be fully adopted, thirty-five days past its own effective date, and still be waiting on two or three separate legislative bodies before it binds anyone. That is the gap between "the district adopted a Zone 0 rule," which is what gets reported, and "a Zone 0 rule applies at this address," which is what a homeowner needs.

What gets ratified is narrower than the whole ordinance, and the narrowing is revealing. When the Ojai City Council ratified Ordinance 34 on October 28, 2025, it ratified exactly three pieces, the ones its resolution describes as amendments to building standards: Article 3 Section 903, Article 3 Appendix B, and Article 4 Section 604.11. Section 604.11 is the fencing section. The part of a district Zone 0 package that needs a city council's vote is the fence rule.

The practical consequence is uncomfortable but real: two houses a mile apart, in the same district, under the same district ordinance, can be under different law depending on how their councils voted and when. The Ventura County page tracks that roll call. We have now read four of them, though only one, Ojai's, is the adopted record rather than a council packet.

Why this is happening now, when almost nothing else local is allowed to move

There is a reason all of this is landing in the same eighteen months, and it is not only the triennial code cycle. Assembly Bill 130 of 2025 amended Health and Safety Code section 17958, effective June 30, 2025, so that:

"Commencing October 1, 2025, to June 1, 2031, inclusive, a city or county shall not make changes that are applicable to residential units in the provisions adopted pursuant to Section 17922 and published in the California Building Standards Code… unless one of the following conditions is met…"

That is a freeze on local residential building-standard amendments lasting nearly six years, passed as housing-cost policy. Six conditions escape it, and two of the six are these:

"(3) The changes or modifications relate to home hardening.
(4) The building standards relate to home hardening and are proposed for adoption by a fire protection district pursuant to Section 13869.7."

Every local rule described on this page was adopted after the freeze began on October 1, 2025, and every one of them legislates on precisely the subject the freeze leaves open. Condition (4) even names section 13869.7, the fire district route these ordinances keep travelling.

We are not the only ones reading it this way, which is worth saying because everything above is us reading a statute. When the Nevada County Board of Supervisors adopted the 2025 code package on December 16, 2025, the local coverage of that meeting summarized the same provision in one sentence: Assembly Bill 130 "provides some relief by imposing a six-year moratorium on most new residential code changes, with exceptions for fire hardening and emergencies." That is a county building department's working understanding of the freeze, reported from its own presentation, and it matches ours.

Two limits, and we would rather state them than let the tidy version stand. First, we are not telling you which of the six conditions any particular council relied on: the ordinances do not recite one, and we have not asked the cities. The claim here is about subject matter, not about the legal basis any individual ordinance rests on. Second, section 17958 never defines "home hardening," so which provisions qualify is untested, and we know of no case on it. The nearest thing to evidence is that Kensington Fire Protection District's ordinance uses the phrase itself, reciting "defensible space and home hardening measures that include Zone Zero standards," which is a drafter reading the exception the way we do and is not authority.

What this means for you

If you are trying to find out whether a Zone 0 rule reaches your house, the question most people ask is close to useless. "Has my city council passed something about fences" usually gets a blank look from whoever answers the phone, because the councillor did not write it and may not remember voting on it inside a package of building code adoptions.

Ask these two instead. They have answers a clerk can actually give:

1. What does my county fire agency's model ordinance say about Zone 0 and about fences? That is where the text comes from, and it is usually published.
2. Has my own city or fire district adopted the current code cycle, and if it is a district, has my city council ratified the building standards? That is the date your obligations start, and it is a public record.

And if you find that your jurisdiction has adopted one of these, read the replacement trigger before you hire anyone. In the Riverside family, replacing part of a fence run within five feet obliges you to bring the whole run back noncombustible, which is the reverse of the state rule that most coverage describes.

What we still do not know

• How many jurisdictions are in each family. We have named three more Riverside cities as leads, on meeting documents rather than codified text, and we do not add a row on a staff report.
• Whether other counties run model texts of their own. Two families in two counties is a pattern, not a survey. On August 24, 2026 we ran the same searches against Los Angeles, San Bernardino and Santa Barbara counties, looking for a shared operative sentence or a county fire code Zone 0 section, and nothing comparable came back. That is worth exactly what it is worth: a search of code libraries and agency publications is not the same as reading those counties' fire codes line by line, which is what we did for Riverside and San Diego, and it is how we missed Riverside the first time.
• Which city councils have ratified which district ordinances. We have read one in full.
• Whether these Zone 0 maintenance duties reach an existing, untouched building, which several of the texts simply do not answer.

We would rather publish those gaps than let a tidy story paper over them. Our standing open questions carry the rest.