Outbuildings

Sheds and outbuildings within 5 feet of the house: what California's adopted Zone 0 rule requires

Fact-checked August 19, 2026·Sources at the end of this article

The one-sentence shed rule

The Zone 0 regulation mostly deals in conditions and exceptions. Its shed provision does not. The Local Responsibility Area text at 14 CCR 1298.04(b)(10) reads in full:

Outbuildings are not permitted in Zone 0 unless they are constructed entirely of Noncombustible materials.

Board of Forestry Zone 0 rule text, 14 CCR 1298.04(b)(10), unchanged from the July 2026 draft through the August 19, 2026 package the Board approved

Two details worth knowing. First, the Board's plain-language summary in the same document says only "non-combustible exterior roofs and walls." The rule text, the enforceable part, says "entirely," and the rule text is what we quote. Second, the two tracks are not word for word the same. The State Responsibility Area rules at 14 CCR 1299.03 run parallel to the Local Responsibility Area rules quoted here, but the SRA text uses "Building or Structure" where the LRA text uses "Occupied Structure," and at least one provision (the fence rule) differs in substance between them. Everything quoted on this page is the LRA text.

"Noncombustible" has a formal definition in the regulation: materials that pass the ASTM E136 furnace test, which measures whether a material itself can burn. In practice, what passes: aluminum, steel, wrought iron, chain link, masonry, concrete, and stone. Wood, vinyl, composite, and fire-retardant-treated wood do not pass. Our materials guide covers the test in detail; the same standard runs through the regulation's fencing provisions.

What counts as an "outbuilding": the 120-square-foot line

The regulation defines the term precisely:

Outbuilding. Buildings or structures that are less than one hundred-twenty (120) square feet in size and not used for human habitation.

Board of Forestry Zone 0 rule text, proposed 14 CCR 1298.03(i), unchanged from the July 2026 draft through the August 19, 2026 package

So the typical backyard storage shed (under 120 square feet, nobody sleeps in it) is an outbuilding. The definition also states that an outbuilding is not an "Occupied Structure," which matters below.

Does a shed get its own 5-foot zone?

Zone 0 is measured around each "Occupied Structure": 5 feet out from the exterior wall, roof, attached deck, stairs, or pergola, or to the property line, whichever comes first. The August package narrowed that definition, and the narrowing matters for measurement: an attached deck, stairs, or pergola counts as part of the structure even when it is built of noncombustible materials, and only noncombustible patios sit outside the definition. Zone 0 is still not measured around outbuildings, so a qualifying outbuilding does not carry its own Zone 0.

The flip side: a shed of 120 square feet or larger, or one used for habitation, is not an "Outbuilding." The regulation defines an Occupied Structure as "Any constructed building or structure that is intended or used for support, enclosure, shelter, or protection of persons, animals, or property, having a permanent roof that is supported by walls or posts." A larger shed meeting that definition would carry its own 5 feet of Zone 0.

Other rulebooks answer the measurement question differently. Berkeley's in-force ordinance requires clearance within 5 feet of "any structure, outbuildings, attached deck or stairs"; Moraga-Orinda's Zone 0, one of the earliest all-structures ordinances in California, also runs from outbuildings. San Diego measures from the primary habitable structure only. IBHS gives each qualifying accessory structure its own zone (more below). Which rulebook applies depends on where you live; start with does Zone 0 apply to my home.

When this would start to apply

Nothing is running today. The regulation is adopted but not in effect, and every deadline in it keys off an effective date that does not exist yet. Once the rule takes effect, new construction complies immediately. For existing homes, the outbuilding provision sits in the final phase, alongside fences and gates:

Existing Occupied Structures must comply with provisions 1298.04(b)(6)-(10) within three (3) years of the effective date of these regulations, or within five (5) years from the effective date of these regulations, on a timeline set by the local agency responsible for fire protection.

Board of Forestry Zone 0 rule text, 14 CCR 1298.04(c)(4), unchanged from the July 2026 draft through the August 19, 2026 package

That is the longest runway in the rule. Once the clock does start, a shed in Zone 0 is a years-out problem rather than a months-out one. Full phasing details are in our timeline and enforcement guide.

Your three options

1. Relocate the shed beyond 5 feet. The Zone 0 shed provision stops at 5 feet from the occupied structure. Move the shed past that line and it no longer applies. Two caveats: the regulation's Zone 1 and Zone 2 rules would require a clearance ring around outbuildings themselves (10 feet to bare mineral soil, plus no flammable vegetation for another 10), and stricter voluntary standards want more distance (see the IBHS and insurance sections below).

2. Replace it with an all-metal shed. The rule never uses the words "metal shed"; no agency document blesses any product category. The test is the material standard: entirely noncombustible, every component passing ASTM E136. Aluminum and steel are materials generally used to meet that test. "Entirely" is doing real work: a steel-panel shed with a wood floor, framing, or trim does not qualify. Check the floor, frame, trim, and door hardware, not just the walls.

3. Rebuild in noncombustible materials. A masonry, concrete, or fully metal structure meets the same standard, the permanent version of option 2.

And a fourth option: if the shed already sits more than 5 feet from every occupied structure, the rule's shed provision does not touch it. Measure before you spend anything. Our Zone 0 checklist walks the whole 5-foot zone item by item.

San Diego and Berkeley: shed rules already in force

Two cities are already enforcing their own versions, and neither copies the state text. More in our local ordinance tracker.

San Diego. The city's Zone 0 guidelines (implementing SDMC §512.0604 in Very High Fire Hazard Severity Zones within city limits) applied to new structures on February 28, 2026 and apply to existing structures beginning February 28, 2027, with a full-compliance target of February 28, 2029. On sheds, the guidelines say detached non-habitable structures such as gazebos, pergolas, and sheds in Zone 0 "must be non-combustible" (though the requirements section allows "non-combustible or ignition-resistant construction," slightly broader than the state rule). Detached outbuildings also get the longest runway of any Zone 0 item: a compliance plan extending beyond 2029, with an affidavit option for homeowners who cannot comply. Details in our San Diego guide.

Berkeley. In the Grizzly Peak and Panoramic mitigation zones, Berkeley's WUI code amendments took effect January 1, 2026, and take a different path than the state rule:

Outbuildings are not permitted in Zone 0, unless constructed according to the standards in Chapter 7A (commencing with Section 701A.1) of Part 2 of Title 24 of the California Code of Regulations. Outbuildings that meet these standards shall be considered part of the Building or Structure for the purpose of measuring Zone 0.

City of Berkeley, 2025 WUI Code Adoption Ordinance, amended CWUI Code Section 604.3.2(1)(f)

Two differences: the standard is Chapter 7A construction rather than "entirely noncombustible," and a compliant outbuilding becomes part of the structure for measurement, meaning Zone 0 extends around the shed itself. Enforcement had a grace period, with inspections reported ramping up through 2026; confirm current practice with Berkeley Fire.

The voluntary layer: IBHS and your insurer

The IBHS Wildfire Prepared Home standard, voluntary but tied to insurance discounts at some carriers, is far stricter. Its base tier requires removing combustible items including sheds from the first 5 feet outright; any structure of 15 square feet or more within 30 feet of the home must sit at least 10 feet away, meet the same wildfire-resilience requirements as the home, and keep its own 0–5-foot noncombustible zone, not overlapping the home's. The Plus tier pushes accessory structures to at least 30 feet. See our IBHS explainer.

Separately, California's Safer from Wildfires insurance regulation (10 CCR §2644.9, in force since 2022) makes sheds one of the mandatory mitigation factors insurers must credit in their rating plans:

Immediate surroundings – removal or absence of combustible structures, including sheds and other outbuildings, from the area within thirty (30) feet of the building being evaluated…

California Department of Insurance, Mitigation in Rating Plans Questionnaire, Section IV(d), implementing 10 CCR §2644.9

Note the direction of that rule: it binds insurers. It requires carriers to offer a rating credit; it does not require you to remove anything, and it does not authorize an insurer to demand it.

What this means for you

As of August 19, 2026, the statewide rule is adopted but not yet in effect, so it requires nothing of your shed today. The practical sequence:

• Check whether Zone 0 would apply to your address. The rule covers State Responsibility Areas and Very High Fire Hazard Severity Zones in local areas, about 17% of California structures. Check your address first.
• Measure. If every wall of the shed is more than 5 feet from the house (and any other occupied structure), the rule's shed provision does not reach it.
• Size it up. Under 120 square feet and non-habitable means "outbuilding": the flat rule applies, but no zone of its own. Larger or habitable means the 5-foot zone may wrap around the shed too.
• If it sits inside 5 feet, plan; don't panic. The provision runs on the 3-to-5-year phase for existing homes, and that clock does not start until the regulation takes effect. Watch the status tracker for the OAL filing and the effective date.
• In San Diego or Berkeley's mitigation zones, the local clock is already running: the local rule, not the state rule, is what an inspector will apply.