CWUIC · California Wildland-Urban Interface Code

How must defensible space be maintained over time?

If your property is in an SRA or local WUI, CWUIC **§ 604** requires you to manage hazardous vegetation so fires don’t spread to buildings; maintain at least **10 ft** of bare mineral soil around outbuildings, make 10–20 ft zones fire‑smart, dispose of cleared fuels only with local approval, and follow the detailed maintenance schedules in the state laws CWUIC references (e.g., PRC § 4291).

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Last reviewed: July 6, 2026

What the code requires — 2–4 sentences

The California Wildland‑Urban Interface Code requires that hazardous vegetation and fuels be managed to reduce wildfire exposure to buildings and the risk of fire spreading to buildings; defensible space must be managed around buildings in State Responsibility Areas (SRA) and other designated WUI areas. The CWUIC § 604.1 and § 604.2 set the general requirement and where it applies, and § 604.3 directs property owners to maintain hazardous vegetation in accordance with existing state laws and regulations (for example Public Resources Code Section 4291).

The single most important rule: Manage and maintain defensible space around buildings in SRAs and designated WUI areas in accordance with CWUIC § 604 and the laws it references so vegetation does not increase wildfire exposure to structures.

Key defined terms (first mention)

Defensible space — the vegetation/fuel management area around a building the code requires be maintained (§ 604.1).
State Responsibility Area (SRA) — areas where the State is responsible for wildfire protection and CWUIC maintenance rules apply (§ 604.1–604.2).

Requirements in detail

Who must maintain defensible space

Owners and occupiers of buildings/structures located in:
- All unincorporated lands designated as a State Responsibility Area (SRA);
- Very High Fire Hazard Severity Zones designated by a city/local agency; and
- Local WUI ordinance areas.
  These applicability rules are in § 604.2.

What standards apply (how to maintain)

CWUIC does not restate every maintenance action; instead it requires hazardous vegetation and fuels around buildings to be maintained in accordance with underlying laws and regulations listed in § 604.3. Those include Public Resources Code Section 4291, Title 14 CCR Section 1299.03, Government Code Section 51182, and Title 19 CCR Section 3.07. Follow those statutes/regulations for the specific ongoing actions and frequencies the law requires. § 604.3.
Where CWUIC adds an explicit numeric maintenance requirement it is in § 604.4 for outbuildings: a minimum clearance of 10 feet (3048 mm) down to bare mineral soil in all directions; vegetation located more than 10 feet but less than 20 feet (6096 mm) from outbuildings must be fire‑smart vegetation.

Disposal and removal of cleared vegetation

Disposal (including burning or removal to an approved site) of flammable vegetation created by construction or clearing must be done in accordance with applicable laws and local-jurisdiction approval in consultation with the fire authority, per § 604.5.

Table — Decision‑relevant dimensions and values

Decision dimension	Required value / action	Code reference
Applicability (where rule applies)	SRA; local Very High Fire Hazard Severity Zones; city/local WUI ordinance areas	§ 604.2
General duty to manage hazardous vegetation	Maintain to reduce exterior wildfire exposure to buildings; follow listed laws/regs	§ 604.1, § 604.3
Laws/regulations to govern specific maintenance details	Follow PRC § 4291; Title 14 CCR § 1299.03; Gov. Code § 51182; Title 19 CCR § 3.07	§ 604.3
Outbuilding clearance	Minimum 10 ft (3048 mm) down to bare mineral soil in all directions	§ 604.4
Vegetation near outbuildings (10–20 ft)	Vegetation >10 ft but <20 ft must be fire‑smart	§ 604.4
Disposal of cleared fuels	Burning or removal only to sites approved by local jurisdiction in consultation with the fire authority; comply with laws	§ 604.5

Ongoing / over‑time maintenance: practical implications

CWUIC places the obligation to maintain defensible space but relies on the referenced statutes/regulations for the specific ongoing actions and frequency (for example branch trimming, removal of dead vegetation, ladder fuel management, etc.). See § 604.3. If you need the exact periodic schedule (annual, seasonal, etc.), consult Public Resources Code Section 4291 and the other referenced regulations because CWUIC points to them for details.
For voluntary homeowner best practices (cleaning roofs, gutters, decks, and keeping combustible materials away from openings), consult Appendix G guidance (G101.3.1). Appendix G is voluntary/best practices—not the mandatory § 604 requirements—but it is useful for practical maintenance.

Exceptions & special cases

CWUIC § 604.5 requires disposal to follow applicable laws and local approval; however, approved public/private dumping areas are an exception to some disposal restrictions (see related Appendix A exceptions). For details on allowed ash/coals handling and approved disposal exceptions consult Appendix A and local rules.
Where the CWUIC references other laws for specifics (e.g., PRC 4291), any narrower or additional local ordinance requirements also apply—CWUIC does not replace those local or state mandates. § 604.3.

Common mistakes

Treating Appendix G recommendations as mandatory code — Appendix G provides voluntary best practices; the mandatory duties come from § 604 and the statutes/regulations it references.
Assuming CWUIC gives complete step‑by‑step schedules (it doesn’t). CWUIC § 604.3 points to PRC § 4291 and other regulations for the operational specifics and frequencies. If you rely only on CWUIC text you may miss enforcement timeframes.
Forgetting outbuildings: owners sometimes apply house clearances to sheds incorrectly — § 604.4 requires 10 ft to bare mineral soil around outbuildings and different rules for 10–20 ft.
Burning or moving cleared vegetation without local approval: § 604.5 requires disposal comply with local jurisdiction approval and applicable laws.

Worked example — concrete scenario

Scenario: You own a house and a detached storage shed on an unincorporated parcel inside an SRA. The shed sits 12 feet from a patch of native brush.

Step 1 — Applicability: You are in an SRA, so § 604.2 applies and you must manage hazardous vegetation around structures.

Step 2 — Outbuilding clearance: Because the shed is an outbuilding, § 604.4 requires a minimum 10‑foot (3048 mm) clearance down to bare mineral soil around the shed. That means clear the 0–10 ft radius to bare mineral soil.

Step 3 — Vegetation in the 10–20 ft zone: Vegetation located more than 10 ft but less than 20 ft from the shed must be fire‑smart vegetation. Since the brush starts at 12 ft, you must ensure that brush in the 10–20 ft band is replaced or managed as fire‑smart (pruning, spacing, species selection as defined by the referenced regs). § 604.4.

Step 4 — Disposal: The cleared material must be disposed of following § 604.5 — e.g., removed to an approved site or otherwise handled per local rules and in consultation with the fire authority before burning.

Step 5 — Follow the detailed maintenance schedule and practices contained in the laws CWUIC references (PRC § 4291 and relevant CCR/Gov. Code sections) for continuing upkeep. § 604.3. Note: CWUIC points you to those statutes for the detailed, ongoing schedule.

Related provisions

Vegetation plan and planting/spacing rules: § 603 (Vegetation plan; shrub/tree spacing and fuel‑modification distances).
Storage of firewood and combustible materials: § 607 (storage rules referenced elsewhere; see index).
Disposal specifics and burning rules / Appendix A exceptions: Appendix A, including A106 (dumping/ashes) and A104 (ignition source control).
Maintenance of fuel breaks and funding/maintenance mechanisms: § 609.2.6 (where local jurisdictions require fuel breaks, maintenance mechanisms must be established).
Voluntary home‑hardening and maintenance best practices: Appendix G — G101.3.1 provides roof, gutter, deck, door/window, and firewood maintenance recommendations (voluntary guidance).

If you want, I can:

Pull and summarize the exact maintenance actions and frequencies from Public Resources Code § 4291 (that CWUIC references) so you have the full list of mandatory ongoing tasks, or
Produce a homeowner maintenance checklist and seasonal calendar that maps CWUIC § 604 obligations to practical monthly tasks.

Code references

Grounded in the retrieved California Wildland-Urban Interface Code — click a citation to read the verbatim passage:

CWUIC § 3.2 High relevance — show source text
Caulk or plug gaps greater than_ [1] / 8 inch (3.2 mm) in siding and replace any damaged boards, including those with dry rot. 8. Install weather stripping to fill gaps greater than [1] / 8 inch (3.2 mm) between garage doors and door frames to prevent ember intrusion. The weather stripping must be compliant with UL Standard 10C. 9. When it’s time to replace your windows, replace them with multipaned windows that have at least one pane of tempered glass. Choose products that have been approved and labeled as OSFM Wildland-Urban Interface (WUI) Products. 10. When it’s time to replace your siding or deck, use noncombustible, ignition-resistant, or other OSFM-approved Wildland- Urban Interface (WUI) Products. 11. Cover openings to operable skylights with noncombustible metal mesh screen with openings in the screen not to exceed [1] / 8 inch (3.2 mm). 12. Install a minimum 6-inch metal flashing, applied vertically on the exterior of the wall at the deck-to-wall intersection to protect the combustible siding material. 13. Enclose openings beneath decks or cantilevered construction with one of the materials required in Section 504.5. Openings beneath decks which are four feet (1219 mm) or less above grade can be covered with a noncombustible and corrosion- resistant mesh with [1] / 16 -inch (1.6 mm) to [1] / 8 -inch (3.2 mm) openings. 14. Remove or replace combustible fences within 5 feet (1524 mm) of the structure. Detached fences that are located within 5 feet (1524 mm) of the structure should be replaced with noncombustible or ignition-resistant building materials.

G101.3 Defensible space features. The maintenance and defensible space features listed in Section G101.3.1 were developed as a best practices guide to assist homeowners to increase the effectiveness of their defensible space and improve the effects of the home-harden- ing features to increase the survivability of their homes from wildfires.

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APPENDIX G—VOLUNTARY HOME-HARDENING RECOMMENDATIONS

G101.3.1 Maintenance and defensible space. The following maintenance and operational procedures assist to limit the impact on a home from an approaching wildfire. 1. Roofs—regularly clean your roof, including roof-to-wall intersections and skylights to remove accumulated fallen leaves, needles and other flammable materials; repair damaged or deteriorated sections of the roof or roof covering; remove all trees, branches, shrubs or other plants adjacent to or overhanging buildings. 2. Rain gutters—keep roof gutters free of combustible debris. 3. Decks—regularly clean your deck, including deck-to-wall intersections to avoid the accumulation of fallen leaves, needles and other flammable materials; ensure that all combustible materials are removed from underneath, on top of or within five feet (1524 mm) of a deck or balcony. _4.
CWUIC § 6-4 High relevance — show source text
structure.

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FIRE PROTECTION REQUIREMENTS

SECTION 604—MAINTENANCE OF DEFENSIBLE SPACE

604.1 General. Hazardous vegetation and fuels shall be managed to reduce the severity of potential exterior wildfire exposure to build- ings and to reduce the risk of fire spreading to buildings as required by applicable laws and regulations.

Defensible space shall be managed around all buildings and structures in State Responsibility Areas (SRA) as required in Public Resources Code 4291.

604.2 Application. Buildings and structures located in the following areas shall maintain the required hazardous vegetation and fuel management: 1. All unincorporated lands designated as a State Responsibility Area (SRA). 2. Land designated as a Very High Fire Hazard Severity Zone by a city or local agency. 3. Land designated in a city or local agency ordinance as a wildland-urban interface (WUI) area.

604.3 Requirements. Hazardous vegetation and fuels around all buildings and structures shall be maintained in accordance with the following laws and regulations: 1. Public Resources Code, Section 4291.

2. California Code of Regulations, Title 14, Division 1.5, Chapter 7, Subchapter 3, Article 3, Section 1299.03. 3. California Government Code, Section 51182.

4. California Code of Regulations, Title 19, Division 1, Chapter 7, Subchapter 1, Section 3.07.

604.4 Outbuildings. Outbuildings shall have a minimum clearance of 10 feet (3048 mm) down to bare mineral soil in all directions. Vege- tation more than 10 feet (3048 mm) but less than 20 feet (6096 mm) from outbuildings shall be fire-smart vegetation.

604.5 Disposal of flammable vegetation and fuels. The disposal, including burning or removal to a site approved by the local jurisdic- tion in consultation with the fire authority, of flammable vegetation and fuels caused by site, road and driveway construction shall be in accordance with all applicable laws and regulations. [CCR T14 §1276.05]

SECTION 605—SPARK ARRESTORS

605.1 General. Chimneys serving fireplaces, barbecues, incinerators or decorative heating appliances in which solid or liquid fuel is used shall be provided with a spark arrestor. Spark arrestors shall be constructed of woven or welded wire screening of 12 USA standard gage wire (0.1046 inch) (2.66 mm) having openings not exceeding [1] / 2 inch (12.7 mm).

605.2 Net free area. The net free area of the spark arrestor shall be not less than four times the net free area of the outlet of the chimney.

SECTION 606—LIQUEFIED PETROLEUM GAS INSTALLATIONS

606.1 General. The storage of liquefied petroleum gas (LP-gas) and the installation and maintenance of pertinent equipment shall be in accordance with the California Fire Code .

606.2 Location of containers or tanks. LP-gas containers or tanks shall be located within the defensible space in accordance with the California Fire Code .
CWUIC § 1.5 High relevance — show source text
structure.

(c) (1) The director shall establish a common reporting platform that allows defensible space and home hardening assessment data, collected by the qualified entities, to be reported to the department and shall establish any necessary quality control measure to ensure that the assessment data is accurate and reliable.

(2) The department shall compile the data submitted pursuant to paragraph (1). (d) The director may use the defensible space and home hardening assessment data to do any of the following: (1) Direct inspection and enforcement resources away from landowners who meet or exceed the department’s standards and regulations for maintaining defensible space.

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APPENDIX H—REFERENCED CALIFORNIA DOCUMENTS

(2) Direct inspection and enforcement resources toward landowners who do not meet the department’s standards and regulations for maintaining defensible space. (3) Direct educational resources toward landowners who own or maintain structures that can be hardened to make them more resistant to fire.

(4) Assist in estimating defensible space compliance in the state responsibility area. (e) The department may expand or amend existing programs for the implementation of this section. (f) This section does not grant any right of entry onto private land or regulatory or enforcement authority to participating quali- fied entities.

(g) Any local governmental entity that is qualified to conduct defensible space assessments pursuant to this section in very high and high fire hazard severity zones, as identified by the State Fire Marshal pursuant to Section 51178 of the Government Code or Article 9 (commencing with Section 4201) of this chapter or by a local agency pursuant to Section 51179 of the Government Code and reports that information to the department, shall report that information using the common reporting platform established pursuant to subdivision (c). (h) (1) On December 31, 2023, and annually thereafter, the department shall report to the Legislature all defensible space data collected pursuant paragraph (2) of subdivision (c). The report may include information on the proportion of unique parcels that were inspected, the degree of compliance with requirements set forth in Section 4291, any enforcement actions that may have been taken for noncompliant parcels, and the proportion of parcels that were found to be in compliance across jurisdictions. At minimum, the report shall include data with sufficient detail to facilitate comparisons of community compliance with the requirements of Section 4291 between local governmental entities qualified to conduct defensible space assessments pursuant to this section and local governmental entities that are not. (2) A report submitted pursuant to this subdivision shall be submitted in compliance with Section 9795 of the Government Code.

(i) This section shall remain in effect only until January 1, 2026, and as of that date is repealed.

SECTION H104—CALIFORNIA CODE OF REGULATIONS, TITLE 14, DIVISION 1.5

H104.1 Subchapter 2 State Minimum Fire Safe Regulations.

1270.01 Definitions.
CWUIC § 609.2.3 High relevance — show source text
609.2.3 Location of fuel breaks. Fuel breaks may be required at locations such as, but not limited to: (1) Directly adjacent to defensible space as defined by Title 14 CCR Section 1299.02 to reduce radiant and convective heat expo- sure and ember impacts, or support firefighting tactics. (2) Directly adjacent to roads to manage radiant and convective heat exposure and ember impacts, increase evacuation safety, or support firefighting tactics. (3) Directly adjacent to a hazardous land use to limit the spread of fire from such uses, reduce radiant and convective heat exposure, or support firefighting tactics. (4) Strategically located along ridgelines, in greenbelts, or in other locations to reduce radiant and convective heat exposure and ember impacts, or support community level firefighting tactics.

[CCR T14 §1276.03(d)]

609.2.4 Timing. Fuel breaks shall be completed prior to the commencement of any permitted construction. [CCR T14 §1276.03(e)]

609.2.5 Construction. Fuel breaks shall be constructed using the most ecologically and site appropriate treatment option, such as, but not limited to, prescribed burning, manual treatment, mechanical treatment, prescribed herbivory, and targeted ground applica- tion of herbicides. [CCR T14 §1276.03(f)]

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FIRE PROTECTION REQUIREMENTS

609.2.6 Maintenance of fuel breaks. Where a local jurisdiction requires fuel breaks, maintenance mechanisms shall be established to ensure the fire behavior objectives and thresholds are maintained over time.

The mechanisms required shall be binding upon the property for which the fuel break is established, shall ensure adequate main- tenance levels, and may include: written legal agreements; permanent fees, taxes, or assessments; assessments through a homeowners’ association; or other funding mechanisms. [CCR T14 §1276.03(g) and (h)]

609.2.7 Greenbelts, greenways, open spaces and parks. Where a greenbelt, greenway, open space, park, landscaped or natural area or portion thereof is intended to serve as a fuel break, the space or relevant portion thereof shall conform with the requirements in California Code of Regulations, Title 14, Section 1276.03. [CCR T14 §1276.04]

SECTION 610—FIRE SAFE DEVELOPMENT REGULATIONS

610.1 General. Pursuant to Public Resources Code, Section 4290, all residential, commercial and industrial building construction within state responsibility areas approved after January 1, 1991, and within lands classified and designated as an LRA Very High Fire Hazard Severity Zone, as defined in subdivision (i) of Section 51177 of the Government Code after July 1, 2021, shall comply with the SRA Fire Safe Development Regulations as specified in Title 14, Division 1.5, Chapter 7, Subchapter 2.
CWUIC § 3.1 High relevance — show source text
Detached fences that are located within 5_ feet (1524 mm) of the structure should be replaced with noncombustible or ignition-resistant building materials.

G101.3 Defensible space features. The maintenance and defensible space features listed in Section G101.3.1 were developed as a best practices guide to assist homeowners to increase the effectiveness of their defensible space and improve the effects of the home-harden- ing features to increase the survivability of their homes from wildfires.

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APPENDIX G—VOLUNTARY HOME-HARDENING RECOMMENDATIONS

G101.3.1 Maintenance and defensible space. The following maintenance and operational procedures assist to limit the impact on a home from an approaching wildfire. 1. Roofs—regularly clean your roof, including roof-to-wall intersections and skylights to remove accumulated fallen leaves, needles and other flammable materials; repair damaged or deteriorated sections of the roof or roof covering; remove all trees, branches, shrubs or other plants adjacent to or overhanging buildings. 2. Rain gutters—keep roof gutters free of combustible debris. 3. Decks—regularly clean your deck, including deck-to-wall intersections to avoid the accumulation of fallen leaves, needles and other flammable materials; ensure that all combustible materials are removed from underneath, on top of or within five feet (1524 mm) of a deck or balcony. 4. Chimneys—ensure spark arrestor is in place; remove all branches within 10 feet of any chimney or stovepipe outlet. 5. Windows—remove or relocate all combustibles away from windows. Older windows that are single-pane or double-pane without tempering can be vulnerable to direct flame contact or radiant heat exposure; remove vegetation or other combus- tible materials that are within five feet of windows.

6. Doors—inspect the door for dry rot, gaps, cracks and warping and caulk or plug gaps greater than [1] / 8 inch. Install weather stripping to fill gaps greater than [1] / 8 inch (3.2 mm) between garage doors and door frames to prevent ember intrusion; remove vegetation or other combustible materials that are within five feet (1524 mm) of doors. 7. Exterior walls—inspect exterior siding for dry rot, gaps, cracks and warping and caulk or plug gaps greater than [1] / 8 inch in siding and replace any damaged boards, including those with dry rot. 8. Firewood—exposed firewood is stored at least 30 feet (9144 mm) away from structures or completely covered in a fire-resis- _tant material that will not allow embers to penetrate.
CWUIC § 603.4.1 High relevance — show source text
603.4.1 Shrubs. All new plantings of shrubs shall comply with the following: 1. Shrubs shall not exceed 6 feet (1829 mm) in height. 2. Groupings of shrubs are limited to a maximum aggregate diameter of 10 feet (3048 mm). 3. Shrub groupings shall be separated from other groupings a minimum of 15 feet (4572 mm). 4. Shrub groupings shall be separated from structures a minimum of 30 feet (9144 mm). 5. Where shrubs are located below or within a tree’s drip line, the lowest tree branch shall be a minimum of three times the height of the understory shrubs or 10 feet (3048 mm), whichever is greater.

603.4.2 Trees. Trees shall be managed as follows within the 30-foot zone (9144 mm) of a structure: 1. New trees shall be planted and maintained so that the tree’s drip line at maturity is a minimum of 10 feet (3048 mm) from any combustible structure. 2. The horizontal distance between crowns of new trees and crowns of adjacent trees shall not be less than 10 feet (3048 mm). 3. Existing trees shall be trimmed to provide a minimum separation of 10 feet (3048 mm) away from chimney and stovepipe outlets per California Code of Regulations, Title 14, Section 1299.03.

603.4.2.1 Nonfire-smart vegetation. New trees not classified as fire-smart vegetation, such as conifers, palms, pepper trees and eucalyptus species, shall be permitted provided the tree is planted and maintained in accordance with one of the following: 1. The tree is planted so that the tree’s drip line at maturity is a minimum of 30 feet (9144 mm) from an applicable building. 2. The tree is planted so that the tree’s drip line at maturity is a minimum of 10 feet (3048 mm) from any combustible struc- ture, and is well pruned and maintained so as not to form a means of rapidly transmitting fire from other nearby vegetation to the structure or from the structure to nearby vegetation or to interrupt the advance of embers toward a

structure.

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FIRE PROTECTION REQUIREMENTS

SECTION 604—MAINTENANCE OF DEFENSIBLE SPACE

604.1 General. Hazardous vegetation and fuels shall be managed to reduce the severity of potential exterior wildfire exposure to build- ings and to reduce the risk of fire spreading to buildings as required by applicable laws and regulations.

Defensible space shall be managed around all buildings and structures in State Responsibility Areas (SRA) as required in Public Resources Code 4291.

604.2 Application. Buildings and structures located in the following areas shall maintain the required hazardous vegetation and fuel management: 1. All unincorporated lands designated as a State Responsibility Area (SRA). 2. Land designated as a Very High Fire Hazard Severity Zone by a city or local agency. 3. Land designated in a city or local agency ordinance as a wildland-urban interface (WUI) area.

CWUIC § 1.5 High relevance — show source text

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APPENDIX H—REFERENCED CALIFORNIA DOCUMENTS

2025 CWUIC—continued	Col2	Adopted Yes/No	IWUIC Section	CBC Section	CFC Section	Title 14, Division 1.5 Section	Title 19, Division 1 Section	Gov Code Section	PRC Section	HSC Section
Section	Title	Title	Title	Title	Title	Title	Title	Title	Title	Title
Chapter 6	Fire protection requirements	Fire protection requirements	Fire protection requirements	Fire protection requirements	Fire protection requirements	Fire protection requirements	Fire protection requirements	Fire protection requirements	Fire protection requirements	Fire protection requirements
603.4.1	Shrubs	Y			4906.4.1
603.4.2	Trees	Y			4906.4.2	1299.03	3.07(b)(3)
603.4.2.1	Nonfire-smart vegetation	Y			4906.4.2.1
604	Maintenance of defensible space	Y			4907
604.1	General	Y			4907.1					4291
604.2	Application	Y			4907.2
604.3	Buildings and structures	Y		701A.3.1	4907.3
604.4	Outbuildings	Y				1299.03(c)(1)
604.5	Disposal of flammable vegetation and fuels	Y				1276.05
605	Spark arrestors	Y		2113.9.2			3.07(b)(6)
605.1	General	Y		2113.9.2 #2 2113.9.2 #3	605.8.2
605.2	Net free area	Y		2113.9.2 #1
606	Liquefied petroleum gas installations	Y			6103
606.1	General	Y			6103.2.1
606.2	Location of contain- ers or tanks	Y			6104.3
606.3	Clear area	Y				1299.03(c)(1)
607	Storage of firewood and combustible materials	Y
607.1	General	Y				1299.03(a)(3) 1299.03(b)(2)(c)
607.2	Storage for off-site use	Y	607.2
608	Building siting and setbacks	Y				1276.00
608.1	Intent	Y				1276.01
_608.

CWUIC § A107 High relevance — show source text
Exception: Approved public and approved private dumping areas.

A106.2 Ashes and coals. Ashes and coals shall not be placed, deposited or dumped in or on wildland-urban interface areas.

Exceptions:
1. In the hearth of an established fire pit, camp stove or fireplace.
2. In a noncombustible container with a tightfitting lid, which is kept or maintained in a safe location not less than 10 feet (3048 mm) from nonfire-smart vegetation or structures.
3. Where such ashes or coals are buried and covered with 1 foot (305 mm) of mineral earth not less than 25 feet (7620 mm) from nonfire-smart vegetation or structures.
SECTION A107—PROTECTION OF PUMPS AND WATER STORAGE FACILITIES

A107.1 General. The reliability of the water supply shall be in accordance with Sections A107.2 through A107.5.

A107.2 Objective. The intent of this section is to increase the reliability of water storage and pumping facilities and to protect such systems against loss from intrusion by fire.

A107.3 Fuel modification area. Water storage and pumping facilities shall be provided with a defensible space of not less than 30 feet (9144 mm) clear of nonfire-resistive vegetation or growth around and adjacent to such facilities.

Persons owning, controlling, operating or maintaining water storage and pumping systems requiring this defensible space are responsible for clearing and removing nonfire-smart vegetation and maintaining the defensible space on the property owned, leased or controlled by said person.

A107.4 Trees. Portions of trees that extend to within 30 feet (9144 mm) of combustible portions of water storage and pumping facilities shall be removed.

A107.5 Protection of electrical power supplies. Where electrical pumps are used to provide the required water supply, such pumps shall be connected to a standby power source to automatically maintain electrical power in the event of power loss. The standby power source shall be capable of providing power for not less than 2 hours in accordance with Chapter 27 of the California Building Code, Section 1203 of the California Fire Code and the California Electrical Code.

Exception: A standby power source is not required where the primary power service to pumps is underground as approved by the code official.

SECTION A108—LAND USE LIMITATIONS

A108.1 General. Temporary fairs, carnivals, public exhibitions and similar uses must comply with all other provisions of this code in addition to enhanced ingress and egress requirements.

A108.2 Objective. The increased public use of land or structures in wildland-urban interface areas increases the potential threat to life safety. The provisions of this section are intended to reduce that threat.

A108.3 Permits. Temporary fairs, carnivals, public exhibitions or similar uses shall not be allowed in a designated wildland-urban interface area, except by permit from the code official.

Permits shall incorporate such terms and conditions that will reasonably safeguard public safety and property.

A108.4 Access roadways. In addition to the requirements in Section 403, access roadways shall be not less than 24 feet (7315 mm) wide and posted NO PARKING. Two access roadways shall be provided to serve the permitted use area.

Where required by the code official to facilitate emergency operations, approved emergency vehicle operating areas shall be provided.

APPENDIX A-6 2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE

CWUIC § 3.2.2 High relevance — show source text

3.2.2|Minimum clearance
to be maintained|N|||||||4293
4296|| |A102.3.2.3|Electrical power line
emergencies|N||||||||| |A102.4|Correction of
condition|N||||||||| |A103|Access restrictions|N||||||||| |A103.1|Restricted entry to
public lands|N||||||||| |A103.2|Trespassing on
posted private
property|N||||||||| |A103.2.1|Signs|N||||||||| |A103.2.2|Trespassing|N||||||||| |A103.3|Use of fire roads and
defensible space|N||||||||| |A103.3.1|Obstructions|N||||||||| |A103.4|Use of motorcycles,
motor scooters, ultra-
light aircraft and
motor vehicles|N||||||||| |A103.5|Tampering with
locks, barricades,
signs and address
markers|N|||||||||

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APPENDIX H—REFERENCED CALIFORNIA DOCUMENTS

2025 CWUIC—continued	Col2	Adopted Yes/No	IWUIC Section	CBC Section	CFC Section	Title 14, Division 1.5 Section	Title 19, Division 1 Section	Gov Code Section	PRC Section	HSC Section
Section	Title	Title	Title	Title	Title	Title	Title	Title	Title	Title
Appendix A	General requirements	General requirements	General requirements	General requirements	General requirements	General requirements	General requirements	General requirements	General requirements	General requirements
A103.5.1	Gates, doors, barriers and locks	N
A104	Ignition source control	N
A104.1	General	N
A104.2	Objective	N
A104.3	Clearance from igni- tion sources	N
A104.4	Smoking	N
A104.5	Equipment and devices generating heat, sparks or open flames	N
A104.6	Fireworks	N
A104.6.1	Authority to seize	N
A104.7	Outdoor fires	N
A104.7.1	General	N
A104.7.2	Permits	N
A104.7.3	Restrictions	N
A104.8	Incinerators, outdoor fireplaces, perma- nent barbecues and grills	N
A104.8.1	Maintenance	N
A104.

CWUIC § 3.2.2 High relevance — show source text

TABLE A102.3.2.2—MINIMUM CLEARANCES BETWEEN VEGETATION AND ELECTRICAL LINES TO BE MAINTAINED	Col2
LINE VOLTAGE	MINIMUM CLEARANCE (inches)
750–35,000	6
35,001–60,000	12
60,001–115,000	19
115,001–230,000	30.5
230,001–500,000	115
For SI: 1 inch = 25.4 mm.	For SI: 1 inch = 25.4 mm.

A102.3.2.3 Electrical power line emergencies. During emergencies, the utility shall perform the required work to the extent necessary to clear the hazard. An emergency can include situations such as trees falling into power lines or trees in violation of Table A102.3.2.2.

A102.4 Correction of condition. The code official is authorized to give notice to the owner of the property on which conditions regulated by Section A102 exist to correct such conditions. If the owner fails to correct such conditions, the legislative body of the jurisdiction is authorized to cause the same to be done and make the expense of such correction a lien on the property where such condition exists.

SECTION A103—ACCESS RESTRICTIONS

A103.1 Restricted entry to public lands. The code official is authorized to determine and publicly announce when wildland-urban interface areas shall be closed to entry and when such areas shall again be opened to entry. Entry on and occupation of wildlandurban interface areas, except public roadways, inhabited areas or established trails and campsites that have not been closed during such time when the wildland-urban interface area is closed to entry, is prohibited.

Exceptions:

Residents and owners of private property within wildland-urban interface areas and their invitees and guests going to or being on their lands.
Entry, in the course of duty, by peace or police officers, and other duly authorized public officers, members of a fire department and members of the Wildland Firefighting Service.

A103.2 Trespassing on posted private property. Where the code official determines that a specific area within a wildland-urban interface area presents an exceptional and continuing fire danger because of the density of natural growth, difficulty of terrain, proximity to structures or accessibility to the public, such areas shall be restricted or closed until changed conditions warrant termination of such restriction or closure. Such areas shall be posted in accordance with Section A103.2.1.

A103.2.1 Signs. Approved signs prohibiting entry by unauthorized persons and referring to this code shall be placed on every closed area.

A103.2.2 Trespassing. Entering and remaining within areas closed and posted is prohibited.

Exception: Owners and occupiers of private or public property within closed and posted areas; their guests or invitees; authorized persons engaged in the operation and maintenance of necessary utilities such as electrical power, gas, telephone, water and sewer; and local, state and federal public officers and their authorized agents acting in the course of duty.

A103.3 Use of fire roads and defensible space. Motorcycles, motor scooters and motor vehicles shall not be driven or parked on, and trespassing is prohibited on, fire roads or defensible space beyond the point where travel is restricted by a cable, gate or sign, without the permission of the property owners. Vehicles shall not be parked in a manner that obstructs the entrance to a fire road or defensible space.

Exception: Public officers acting within their scope of duty.

CWUIC § 2.1. High relevance — show source text
A103.2 Trespassing on posted private property. Where the code official determines that a specific area within a wildland-urban interface area presents an exceptional and continuing fire danger because of the density of natural growth, difficulty of terrain, proximity to structures or accessibility to the public, such areas shall be restricted or closed until changed conditions warrant termination of such restriction or closure. Such areas shall be posted in accordance with Section A103.2.1.

A103.2.1 Signs. Approved signs prohibiting entry by unauthorized persons and referring to this code shall be placed on every closed area.

A103.2.2 Trespassing. Entering and remaining within areas closed and posted is prohibited.

Exception: Owners and occupiers of private or public property within closed and posted areas; their guests or invitees; authorized persons engaged in the operation and maintenance of necessary utilities such as electrical power, gas, telephone, water and sewer; and local, state and federal public officers and their authorized agents acting in the course of duty.

A103.3 Use of fire roads and defensible space. Motorcycles, motor scooters and motor vehicles shall not be driven or parked on, and trespassing is prohibited on, fire roads or defensible space beyond the point where travel is restricted by a cable, gate or sign, without the permission of the property owners. Vehicles shall not be parked in a manner that obstructs the entrance to a fire road or defensible space.

Exception: Public officers acting within their scope of duty.

A103.3.1 Obstructions. Radio and television aerials, guy wires thereto, and other obstructions shall not be installed or maintained on fire roads or defensible spaces, unless located 16 feet (4877 mm) or more above such fire road or defensible space.

A103.4 Use of motorcycles, motor scooters, ultralight aircraft and motor vehicles. Motorcycles, motor scooters, ultralight aircraft and motor vehicles shall not be operated within wildland-urban interface areas, without a permit by the code official, except on clearly established public or private roads. Permission from the property owner shall be presented when requesting a permit.

APPENDIX A-4 2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

APPENDIX A—GENERAL REQUIREMENTS

A103.5 Tampering with locks, barricades, signs and address markers. Locks, barricades, seals, cables, signs and address markers installed within wildland-urban interface areas, by or under the control of the code official, shall not be tampered with, mutilated, destroyed or removed.

A103.5.1 Gates, doors, barriers and locks. Gates, doors, barriers and locks installed by or under the control of the code official shall not be unlocked.

SECTION A104—IGNITION SOURCE CONTROL

A104.1 General. Ignition sources shall be controlled in accordance with Sections A104.2 through A104.10.

A104.2 Objective. Regulations in this section are intended to provide the minimum requirements to prevent the occurrence of wildfires.

A104.3 Clearance from ignition sources. Clearance between ignition sources and grass, brush or other combustible materials shall be maintained at not less than 30 feet (9144 mm).
CWUIC § 5-3 High relevance — show source text
502 Reserved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-3

503 Ignition-Resistant Construction and Material. . . . . .5-3

504 Ignition-Resistant Construction. . . . . . . . . . . . . . . . . .5-4

505 Reserved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-9

506 Reserved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-9

507 Replacement or Repair of Roof Coverings. . . . . . . . .5-9

CHAPTER 6 FIRE PROTECTION REQUIREMENTS. . . . . . .6-3

601 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3

602 Fire Protection Plans . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3

603 Vegetation Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4

604 Maintenance of Defensible Space . . . . . . . . . . . . . . . 6-5

605 Spark Arrestors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5

606 Liquefied Petroleum Gas Installations . . . . . . . . . . . 6-5

607 Storage of Firewood and Combustible Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5

608 Building Siting and Setbacks . . . . . . . . . . . . . . . . . . . . 6-5

609 Ridgelines, Fuel Breaks and Greenbelts . . . . . . . . . . . 6-6

610 Fire Safe Development Regulations . . . . . . . . . . . . . . 6-7

611 Subdivision Review Survey . . . . . . . . . . . . . . . . . . . . . . 6-7

612 General Plan Safety Element . . . . . . . . . . . . . . . . . . . . 6-7

CHAPTER 7 REFERENCED STANDARDS . . . . . . . . . . . . . .7-3

APPENDIX A GENERAL REQUIREMENTS . . . . APPENDIX A-3

A101 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX A-3

A102 Vegetation Control. . . . . . . . . . . . . . . . . . . APPENDIX A-3

Frequently asked questions

Who is responsible for maintaining defensible space?

The property owner or occupier is responsible for maintaining hazardous vegetation and fuels around buildings located in SRAs, Very High Fire Hazard Severity Zones, or locally designated WUI areas as required by § 604.2 and § 604.3.

Is Appendix G mandatory?

No. Appendix G (including G101.3.1 maintenance tips) is voluntary best practice guidance. Mandatory maintenance obligations come from § 604 and the laws/regulations it references (e.g., PRC § 4291).

What clearance is required around outbuildings?

Outbuildings require a minimum 10‑foot (3048 mm) clearance down to bare mineral soil in all directions; vegetation >10 ft and <20 ft from outbuildings must be fire‑smart, per § 604.4.

Can I burn the vegetation I clear?

Not without following § 604.5: disposal (including burning) must comply with applicable laws and local jurisdiction approval in consultation with the fire authority. Check local rules before burning.

Where are the specific “how often” and “how much” rules?

CWUIC § 604.3 points to other state statutes and CCR/Government Code sections (for example PRC § 4291) for the detailed operational requirements and frequencies. CWUIC sets the duty and points you to those laws for specifics.

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California Wildland-Urban Interface Code