What Zone 0 Actually Requires: A Homeowner's Checklist While California Finishes the Rule
I get some version of this question constantly from customers who've heard "Zone 0" mentioned on the news: "Is this actually a law yet, or is everyone just talking about it?" Good question, and the honest answer is: both, sort of. The rule isn't finalized, but the requirements behind it are already well-defined, and nothing about waiting for the state to finish paperwork makes your first five feet less flammable in the meantime. So here's what the regulation actually asks for, where it really stands as of this week, and what I'd do regardless of which way the final date lands.
After the 2018 Woolsey Fire burned through the hills near my home in West Hills, I went through CERT training and spent a lot of time afterward trying to separate what the fire science actually says from what gets repeated secondhand. Zone 0 is one of the more misunderstood pieces of wildfire prep I run into, mostly because people have heard the name but not the specifics. Let's fix that.
What Zone 0 Actually Covers
Zone 0 is the "ember-resistant zone" — the first 5 feet measured out from your structure, including attached decks and stairs. It's a narrower, stricter cousin of the broader defensible space rules (Zones 1 and 2) that already apply at 30 and 100 feet. The thinking behind it comes from the same research I've mentioned before: most homes lost in wildland-urban interface fires don't go up because a wall of flame rolls through — they go up because a wind-blown ember lands on something ignitable right against the house and starts a small fire the structure can't survive.
Based on the current draft rule package the Board of Forestry and Fire Protection has been working through, Zone 0 is built around removing exactly that kind of material from the five feet closest to your walls:
- Combustible mulch and bark — swapped for gravel, pavers, or other non-combustible groundcover.
- Dry grass, dead vegetation, and most woody plants or shrubs growing directly against the structure.
- Stored firewood or lumber kept against the house instead of relocated further out.
- Synthetic turf, which the draft rule treats as a combustible for this purpose, not an exception.
- Anything stacked against the siding — patio cushions, doormats, debris in gutters, items that would otherwise catch an ember.
One detail that's easy to miss: the draft guidance also calls out a 6-inch vertical clearance between bare ground and the bottom of your siding as meaningfully better at keeping embers from finding a foothold. It's a small thing, but it's the kind of detail that separates "technically cleared" from actually ember-resistant.
Where the Rule Actually Stands Right Now
This is the part that causes most of the confusion, so I want to be precise about it rather than repeat a date I can't verify. Zone 0 traces back to AB 3074, and Governor Newsom's Executive Order N-18-25 directed the Board of Forestry to finish rulemaking by December 31, 2025. That deadline has already passed. As of the Board's most recent full meeting this year, the regulation package was still with the Office of Administrative Law for final review — meaning it has not yet been published as a final, effective rule.
What the draft framework does lay out, assuming it's finalized close to its current form:
- New construction in State Responsibility Area fire zones would need to comply immediately once the rule takes effect.
- Existing homes in State Responsibility Areas and Very High Fire Hazard Severity Zones within Local Responsibility Areas would get roughly a three-year phase-in period after the rule is finalized to come into compliance.
- Both the Board and most county fire officials have said publicly they expect enforcement to lean on education first, not citations — the goal is getting the work done, not catching people out.
None of that is a reason to wait. The three-year phase-in only helps you if you haven't already done the work; if you clear your five feet now, you're simply done early, on your own schedule, instead of during whatever crunch comes once a final date is on the books.
A Zone 0 Walk-Through You Can Do This Weekend
- Measure out 5 feet from every exterior wall, deck, and stairway — it's closer to the house than most people assume.
- Pull mulch, bark, and dead leaves back from that zone and replace with gravel, rock, or pavers where you can.
- Move firewood stacks, lumber, and anything flammable at least 5 feet off, and further if you have the room.
- Check what's growing directly against your siding — dry shrubs and overgrown landscaping are the most common miss.
- Clear gutters and roof valleys near the structure; embers collect there as readily as they do at ground level.
- Look under decks and stairs, not just around them — stored items underneath count as being in the zone.
What You Need to Know
- Zone 0 is not yet a final, enforceable state regulation as of this week — it's a draft rule package still finishing review with the Office of Administrative Law, after missing its original December 31, 2025 target.
- The substance of the rule is well-established even though the final date isn't — clearing combustibles from the first 5 feet around your structure is the work, regardless of when it becomes mandatory.
- New construction is expected to comply immediately; existing homes would get roughly a three-year phase-in once the rule is finalized — but doing the work now costs you nothing and starts you ahead.
- Some cities and HOAs already have their own defensible space requirements that go beyond the state minimum — check with your local fire department before assuming Zone 0 is the only rule that applies to you.
- Zone 0 reduces the odds your home ignites — it doesn't put a fire out. It's prevention, not suppression; equipment is what you reach for if an ember gets through anyway.
- Verify current status directly with CAL FIRE or the Board of Forestry before you plan around a specific compliance date — this is a moving regulatory process and I'd rather send you to the source than have you working off secondhand information.
Clearing your five feet is the cheapest, highest-leverage thing you can do for your home's wildfire odds, final rule or not. Once that's done, the other half of being ready is having a way to act if an ember still gets past it.
Sherwin Ross is the founder of Ace Fire Defense, based in West Hills, CA. After the 2018 Woolsey Fire, he became CERT-trained and started building wildfire defense equipment for homeowners.