FIELD NOTE · SUPPLEMENTAL SET
Chapter 7A was deleted: the ember tests a rebuild is specified against now
ISSUEDJULY 11, 2026DRAWN BY THE NIGHTLY SWEEP
A set of rebuild drawings crossing a Los Angeles plan check counter this summer will very often cite Chapter 7A of the California Building Code somewhere in its general notes, because that is where the wildfire construction requirements sat for the whole of two code cycles, and because everyone who learned them learned them there, from the roof classification down through the vents and the eaves to the underside of the deck. The Building Standards Commission's change record for the 2025 cycle disposes of that chapter in a single line. It was deleted from the CBC and its requirements relocated to the California Wildland-Urban Interface Code, a new Part 7 of Title 24, published July 1, 2025 and effective January 1, 2026. What sits at Chapter 7A now is a note directing the reader to CBC Section 101.4.8, and every ignition-resistant requirement a rebuild is specified against has moved into Chapter 5 of a code that did not exist two cycles ago.
The move deserves more attention than a renumbering would, because of what the new code declines to do. Its parent document, the International Wildland-Urban Interface Code, offers three graduated tiers of ignition-resistant construction, Class 1 through Class 3, so that a jurisdiction can set the standard against its own hazard; California reserved Sections 502, 505 and 506, took Class 1 alone, and left the menu on the table. An assembly meets the ignition-resistant requirement or it does not. There is no lower tier to specify down to.
The drawings still cite the deleted chapter.
What the requirement actually consists of is a stack, examined the way an envelope is always examined, outside in: the roof, then the vents, then the eaves, then the wall, then the openings, then the deck and everything under it. Each layer carries its own test, and the tests are not generic fire ratings. Each one simulates a specific way fire arrives at that specific layer.
The subsections after it are the interesting part, because they concern voids rather than materials. Section 504.2.1 requires the spaces between the roof covering and the deck to be closed; 504.2.1.2 specifies the underlayment; 504.2.2 details the valleys. A tile roof passes the brand test on the tile and then loses the building through the airspace under it, which is why the code spends three subsections on gaps and one on the covering.
ASTM E2886 is the clearest illustration of what the whole code is doing. The test drives embers into the vent and looks for flaming ignition on the other side; then it applies direct flame and looks for flaming during the integrity portion; then it measures the unexposed side and requires that it stay at or below 662 degrees Fahrenheit, which is 350 Celsius. Three exposures, in the order a fire delivers them, and the pass condition is that nothing on the interior side ignites.
There is a prescriptive route alongside it, in 504.5.2, and it is a coarser instrument: noncombustible material, ignition-resistant material labelled for exterior use, exterior fire-retardant-treated wood, fire-retardant-treated shingles or shakes qualified as a Class B roof covering over solid sheathing, or an approved assembly such as a one-hour rated wall, heavy timber, a log wall or Type X gypsum. Both routes end at the same wall. Only one of them tells anybody what the wall survives.
Section 504.5.2.1 then closes the seam. The wall covering runs from the top of the foundation to the roof and terminates at 2 inch nominal solid wood blocking between the rafters at every overhang, or at the enclosure where the eaves are enclosed. That detail is the entire argument in one line: a wall assembly rated for ten minutes of direct flame does nothing at all if the ember arrives through the open gap where the wall meets the eave.
Then there is the garage door, where the code stops describing materials and starts dimensioning air. Perimeter gaps may not exceed one eighth of an inch, controlled by weather-stripping, door overlaps or metal flashing, and an automatic opener requires battery backup so the door can still be closed with the power out. That gap is the requirement most likely to be conceded on a Friday afternoon, by a crew that has hung the door plumb and true and has three more to hang, and it is worth as much as the wall assembly behind it.
The draft is also narrower than its summaries. It permits a limited amount of well-maintained plants and trees in parts of Zone 0; it prohibits new combustible fences within the five feet while allowing existing ones to remain and be repaired in the same material; a fence or gate attached to an occupied structure needs a noncombustible section within five years. The landscaping side of that rule has its own trades and its own timeline.
WHERE THE REQUIREMENT MOVED July 1 2025 The 2025 Title 24 edition is published, creating Part 7, the California Wildland-Urban Interface Code January 1 2026 The 2025 edition takes effect; CBC Chapter 7A is deleted and left as a pointer to Section 101.4.8 June 16 2026 The Board of Forestry advisory committee forwards the Zone 0 draft by unanimous vote August 19 2026 The full Board of Forestry takes up Zone 0; nothing in it is in force before that
One boundary matters more than any of the tests, and it is not a building question. The stack applies where the State Fire Marshal's maps say it applies, parcel by parcel, not to every address that burned. A lot outside a designated zone may be built to the same standard voluntarily, and a lot inside one has no choice, and the two lots can face each other across a street.
Sixteen thousand two hundred fifty-one structures were destroyed in the Eaton and Palisades fires, which both started January 7, 2025 and were contained January 31. What comes back on those parcels is a roofing market measured in years, and the work itself is envelope work: roofing, siding, vents, eaves, decking, glazing and doors, which is a different set of trades than the sprinkler trade that the word fire tends to summon. Filings scored nightly for roofing contractors put those jobs in front of the trade while the assembly is still a specification rather than an installation.
The specification is where all of this is decided, and it is decided quickly. An assembly that passes 12-7A-1 and one that satisfies 504.5.2 prescriptively both clear plan check, and one of them was chosen because somebody read what the test does.
The move deserves more attention than a renumbering would, because of what the new code declines to do. Its parent document, the International Wildland-Urban Interface Code, offers three graduated tiers of ignition-resistant construction, Class 1 through Class 3, so that a jurisdiction can set the standard against its own hazard; California reserved Sections 502, 505 and 506, took Class 1 alone, and left the menu on the table. An assembly meets the ignition-resistant requirement or it does not. There is no lower tier to specify down to.
The drawings still cite the deleted chapter.
What the requirement actually consists of is a stack, examined the way an envelope is always examined, outside in: the roof, then the vents, then the eaves, then the wall, then the openings, then the deck and everything under it. Each layer carries its own test, and the tests are not generic fire ratings. Each one simulates a specific way fire arrives at that specific layer.
The roof, rated against a landing ember
The roof assembly must achieve a Class A fire classification, tested to ASTM E108 or UL 790, under Section 504.2. Those are the burning brand and spread-of-flame tests, which is to say the roof is rated against an ember that lands on it and a flame that then runs across the covering.The subsections after it are the interesting part, because they concern voids rather than materials. Section 504.2.1 requires the spaces between the roof covering and the deck to be closed; 504.2.1.2 specifies the underlayment; 504.2.2 details the valleys. A tile roof passes the brand test on the tile and then loses the building through the airspace under it, which is why the code spends three subsections on gaps and one on the covering.
A vent, and 662 degrees on the far side
Vents get two compliance paths under Section 504.10, and they are alternatives rather than a requirement and a detail. Either the vent is listed by the State Fire Marshal as a Wildfire Flame and Ember Resistant vent, or tested to ASTM E2886, under 504.10.1; or, for vents on a sloped roof, it carries noncombustible corrosion-resistant mesh with openings no smaller than one sixteenth of an inch and no larger than one eighth, under 504.10.2. Gable and dormer vents must sit at least 10 feet from a lot line.ASTM E2886 is the clearest illustration of what the whole code is doing. The test drives embers into the vent and looks for flaming ignition on the other side; then it applies direct flame and looks for flaming during the integrity portion; then it measures the unexposed side and requires that it stay at or below 662 degrees Fahrenheit, which is 350 Celsius. Three exposures, in the order a fire delivers them, and the pass condition is that nothing on the interior side ignites.
The wall, ten minutes under a 150 kilowatt burner
The performance path for an exterior wall assembly, under Section 504.5, is SFM Standard 12-7A-1 or ASTM E2707 subject to the conditions of acceptance in 504.9.3. A propane burner verified to 150 kilowatts, which the standard also gives as 8,535 Btu per minute, is held against the assembly for 10 minutes. The assembly passes if no flame penetrates it at any point and if no glowing combustion appears on the interior surface at the end of the 70 minute test. Three tests must pass, not one.There is a prescriptive route alongside it, in 504.5.2, and it is a coarser instrument: noncombustible material, ignition-resistant material labelled for exterior use, exterior fire-retardant-treated wood, fire-retardant-treated shingles or shakes qualified as a Class B roof covering over solid sheathing, or an approved assembly such as a one-hour rated wall, heavy timber, a log wall or Type X gypsum. Both routes end at the same wall. Only one of them tells anybody what the wall survives.
Section 504.5.2.1 then closes the seam. The wall covering runs from the top of the foundation to the roof and terminates at 2 inch nominal solid wood blocking between the rafters at every overhang, or at the enclosure where the eaves are enclosed. That detail is the entire argument in one line: a wall assembly rated for ten minutes of direct flame does nothing at all if the ember arrives through the open gap where the wall meets the eave.
An eighth of an inch, at the garage door
Openings are specified twice over, once for what they are made of and once for how they close. Glazing under 504.8 must be a multilayered panel with at least one pane of tempered glass, or glass block, or rated at least 20 minutes to NFPA 257 or UL 9, or tested to SFM Standard 12-7A-2. Doors under 504.9 must be noncombustible, or solid-core wood at least one and three quarter inches thick, or rated 20 minutes, or tested to ASTM E2707 or SFM 12-7A-1.Then there is the garage door, where the code stops describing materials and starts dimensioning air. Perimeter gaps may not exceed one eighth of an inch, controlled by weather-stripping, door overlaps or metal flashing, and an automatic opener requires battery backup so the door can still be closed with the power out. That gap is the requirement most likely to be conceded on a Friday afternoon, by a crew that has hung the door plumb and true and has three more to hang, and it is worth as much as the wall assembly behind it.
The ground plane, which is not law yet
Zone 0, the ember-resistant five feet around a structure, has been described as a current requirement for most of a year and is not one. The draft rule cleared its advisory committee by unanimous vote on June 16, 2026 and goes to the full Board of Forestry on August 19, 2026. If the Board approves it, staff submit an emergency rulemaking package to the Office of Administrative Law under AB 1455 expedited review, and staff expect it could take effect as early as September 2026: immediately for new construction, phased over five years for existing structures, in State Responsibility Areas and in Very High Fire Hazard Severity Zones inside Local Responsibility Areas.The draft is also narrower than its summaries. It permits a limited amount of well-maintained plants and trees in parts of Zone 0; it prohibits new combustible fences within the five feet while allowing existing ones to remain and be repaired in the same material; a fence or gate attached to an occupied structure needs a noncombustible section within five years. The landscaping side of that rule has its own trades and its own timeline.
WHERE THE REQUIREMENT MOVED July 1 2025 The 2025 Title 24 edition is published, creating Part 7, the California Wildland-Urban Interface Code January 1 2026 The 2025 edition takes effect; CBC Chapter 7A is deleted and left as a pointer to Section 101.4.8 June 16 2026 The Board of Forestry advisory committee forwards the Zone 0 draft by unanimous vote August 19 2026 The full Board of Forestry takes up Zone 0; nothing in it is in force before that
One boundary matters more than any of the tests, and it is not a building question. The stack applies where the State Fire Marshal's maps say it applies, parcel by parcel, not to every address that burned. A lot outside a designated zone may be built to the same standard voluntarily, and a lot inside one has no choice, and the two lots can face each other across a street.
Sixteen thousand two hundred fifty-one structures were destroyed in the Eaton and Palisades fires, which both started January 7, 2025 and were contained January 31. What comes back on those parcels is a roofing market measured in years, and the work itself is envelope work: roofing, siding, vents, eaves, decking, glazing and doors, which is a different set of trades than the sprinkler trade that the word fire tends to summon. Filings scored nightly for roofing contractors put those jobs in front of the trade while the assembly is still a specification rather than an installation.
The specification is where all of this is decided, and it is decided quickly. An assembly that passes 12-7A-1 and one that satisfies 504.5.2 prescriptively both clear plan check, and one of them was chosen because somebody read what the test does.