CWUIC · California Wildland-Urban Interface Code
How are shrubs, trees and nonfire‑smart vegetation regulated?
New plantings in CWUIC fire hazard areas must be **fire‑smart** (see **§ 603.4**) — shrubs are limited to **6 ft** height, **10 ft** grouping diameter, **15 ft** between groupings and **30 ft** from structures (**§ 603.4.1**), while trees in the 30‑ft zone must keep the **drip line** at least **10 ft** from combustible structures and crowns **10 ft** apart (**§ 603.4.2**). Nonfire‑smart trees (e.g., eucalyptus, palms) are allowed only if the mature drip line is **30 ft** from a building OR it is **10 ft** from a structure and is kept well pruned/maintained (**§ 603.4.2.1**) .
Last reviewed: July 6, 2026
What the code requires — plain English
All new vegetation in applicable Fire Hazard Severity Zones must be fire‑smart vegetation unless an exception applies; the general requirement is in § 603.4 . Detailed limits for shrubs are in § 603.4.1 and for trees in § 603.4.2; nonfire‑smart trees are allowed only when they meet one of the siting/maintenance options in § 603.4.2.1 .
The single most important rule: new plantings next to structures must be fire‑smart — or, if they’re nonfire‑smart trees, they must meet the specific distance and maintenance options in § 603.4.2.1 .
Requirements in detail
Key defined term
- Fire‑smart vegetation — plants that have characteristics (high live moisture, little dead material, low resin/sap, etc.) that reduce likelihood of ignition and fire spread. The code gives methods to identify fire‑smart plants and supplemental examples in the informational appendix (see Appendix F) . The requirement to use fire‑smart plants is in § 603.4 .
High‑level rule (where it applies)
- Application: All new plantings in SRAs and LRAs designated as Fire Hazard Severity Zones must comply with Sections 603.3 through 603.4.2.1 (landscape plans and the vegetation rules) — see § 603.2 and § 603.3 for plan requirements and zone delineation; the vegetation rules below are applied within the 30‑foot and 100‑foot fuel management zones identified on plans .
Shrub requirements (§ 603.4.1) — plain rules and why they matter
- Maximum shrub height: 6 feet. § 603.4.1(1) .
- Maximum shrub grouping diameter: 10 feet (aggregate). § 603.4.1(2) .
- Minimum separation between shrub groupings: 15 feet. § 603.4.1(3) .
- Minimum separation from structures: 30 feet. Shrub groupings must be at least 30 feet from structures. § 603.4.1(4) .
- Under‑story under trees: where shrubs are under a tree’s drip line, the tree’s lowest branch must be at least three times the shrub height or 10 feet, whichever is greater, to prevent ladder fuels. § 603.4.1(5) .
Tree requirements (§ 603.4.2)
These rules apply within the 30‑foot zone around a structure (the code asks plans to delineate the 30‑ft zone). Key items:
- Minimum drip‑line clearance of new trees to combustible structures: 10 feet. New trees must be planted/maintained so the mature drip line is at least 10 feet from any combustible structure. § 603.4.2(1) .
- Minimum horizontal crown separation between new trees: 10 feet. The horizontal distance between crowns of new trees must be at least 10 feet. § 603.4.2(2) .
- Existing tree trimming near chimneys/stovepipes: 10 feet. Existing trees must be trimmed to provide at least 10 feet separation from chimney and stovepipe outlets, per referenced CCR Title 14 rules. § 603.4.2(3) .
Nonfire‑smart trees (exception pathway) — § 603.4.2.1
- Trees that are not classified as fire‑smart (examples listed include conifers, palms, pepper trees, eucalyptus) are permitted only if one of these is met:
- The tree’s drip line at maturity is a minimum of 30 feet from the applicable building (i.e., the edge of the canopy must be ≥ 30 feet from the building). § 603.4.2.1(1) .
- OR the tree’s drip line at maturity is a minimum of 10 feet from any combustible structure and the tree is well pruned and maintained so it will not rapidly transmit fire between vegetation and structure or interrupt ember protection. § 603.4.2.1(2) .
Note: the general vegetation requirement remains — new vegetation must be fire‑smart — with the above exception specifically for nonfire‑smart trees only when the siting/maintenance options are satisfied § 603.4 and § 603.4.2.1 .
Decision‑relevant dimensions at a glance (table)
| Decision / dimension | Required value | Why it matters | Code Reference |
|---|---|---|---|
| Shrub max height | 6 ft | Limits ladder fuels and flame contact to structures | § 603.4.1(1) |
| Shrub grouping max aggregate diameter | 10 ft | Prevents large continuous shrub fuel patches | § 603.4.1(2) |
| Separation between shrub groupings | 15 ft | Breaks horizontal continuity of fuels | § 603.4.1(3) |
| Shrub grouping to structure | 30 ft | Keeps shrub fuels away from buildings | § 603.4.1(4) |
| Under‑tree branch clearance above shrubs | ≥ 3× shrub height or 10 ft (whichever greater) | Prevents ladder fuels from shrubs to canopy | § 603.4.1(5) |
| New tree drip line to combustible structure | 10 ft (standard) | Reduce direct flame contact and ember pathways | § 603.4.2(1) |
| Crown‑to‑crown horizontal separation (new trees) | 10 ft | Limits crown‑fire spread between trees | § 603.4.2(2) |
| Existing trees to chimney/stovepipe outlets | 10 ft | Prevent ignition from appliance outlets | § 603.4.2(3) |
| Nonfire‑smart tree option A (drip line) | 30 ft | More conservative siting for high‑risk species | § 603.4.2.1(1) |
| Nonfire‑smart tree option B (drip + maintenance) | 10 ft + well pruned/maintained | Allows closer planting only with ongoing mitigation | § 603.4.2.1(2) |
Exceptions & special cases
- The code expressly permits trees classified as nonfire‑smart only if they comply with § 603.4.2.1 (the two options above). This is the stated exception to the general § 603.4 fire‑smart rule .
- Landscape plans: where required, plans must show the 30‑ft and 100‑ft fuel management zones and identify proposed species, sizes at maturity, and irrigated areas (see § 603.3.1). Site planning can affect how these shrub and tree rules are applied on a project .
- The code references trimming of existing trees to meet 10 ft from chimneys in § 603.4.2(3) and points to CCR Title 14 for the detailed clearance referenced there; local enforcement may apply that CCR guidance as well .
- Appendix F provides informational characteristics of fire‑smart vegetation (descriptive guidance, not additional mandatory distances) and may be used to justify plant choices; it is informational only .
If you need a ruling on whether a particular species is “fire‑smart” for your jurisdiction, the code allows identification by (a) an approved listing, (b) a licensed landscape architect with justification, or (c) local enforcing agency approval under § 603.4 .
Common mistakes
- Measuring from the tree trunk instead of the drip line when checking clearance distances. The code measures the drip line of the mature tree (not trunk‑to‑structure) for the 10 ft / 30 ft tests in § 603.4.2 and § 603.4.2.1 .
- Confusing shrub grouping diameter (aggregate size of a planting island) with single‑plant width — the code limits the grouping aggregate diameter to 10 ft in § 603.4.1(2) .
- Assuming nonfire‑smart trees are banned. They are allowed only by the two options in § 603.4.2.1 (30‑ft drip line or 10‑ft + strict maintenance) — don’t plant a eucalyptus 15 ft from the house and call it compliance unless you meet the maintenance option and local approval § 603.4.2.1 .
- Forgetting ongoing maintenance: option B for nonfire‑smart trees requires the tree be “well pruned and maintained” — that is an ongoing obligation, not a one‑time pruning § 603.4.2.1(2) .
Worked example — applying the rule with numbers
Scenario: You want to plant a nonfire‑smart eucalyptus in front of a home. The mature canopy radius (drip line distance from trunk) is expected to be 20 ft.
Option A (meet § 603.4.2.1(1)): the tree’s drip line at maturity must be at least 30 ft from the building. That means the trunk must be planted at least 30 ft + 20 ft = 50 ft from the building face so the canopy edge (drip line) is 30 ft away — this satisfies § 603.4.2.1(1) .
Option B (meet § 603.4.2.1(2)): if you cannot place the drip line 30 ft away, you may plant so the drip line is at least 10 ft from the structure (trunk must be 10 ft + 20 ft = 30 ft from the structure) but you must keep the tree well pruned and maintained so it will not rapidly transmit fire to/from the building; that continuing maintenance is required by § 603.4.2.1(2) .
Also check shrubs nearby: if you plan a shrub grouping under that tree, each shrub must be ≤ 6 ft tall and the grouping must be ≤ 10 ft aggregate diameter, and if the grouping is below the tree’s drip line the lowest tree branch must be at least three times shrub height or 10 ft (whichever is greater) per § 603.4.1 .
Related provisions
- § 603.2 — Application (scope: plantings in SRA/LRA Fire Hazard Zones) .
- § 603.3 / § 603.3.1 — Landscape plans and required contents (delineation of 30‑ft & 100‑ft zones, species, mature sizes) .
- § 603.4 — General vegetation requirement that new plantings be fire‑smart (controls shrub/tree rules and exception) .
- § 603.4.1 — Shrub-specific requirements (height, grouping, spacing, setback) .
- § 603.4.2 — Tree management within the 30‑foot zone (drip line clearance, crown spacing, chimney clearance) .
- § 603.4.2.1 — Specific requirements/options for nonfire‑smart trees (30‑ft or 10‑ft+maintenance) .
- Appendix F (informational) — Characteristics/examples of fire‑smart vegetation (informational guidance) .
- § 604 — Maintenance of defensible space (ongoing vegetation management obligations) — useful when interpreting the maintenance requirement in § 603.4.2.1(2) .
Code references
Grounded in the retrieved California Wildland-Urban Interface Code — click a citation to read the verbatim passage:
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.
6-4 2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE
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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 § 603.2 High relevance — show source text
603.2 Application. All new plantings of vegetation in State Responsibility Area (SRA) and Local Responsibility Areas (LRA) designated as a Fire Hazard Severity Zone shall comply with Sections 603.3 through 603.4.2.1.
603.3 Landscape plans. Landscape plans shall be provided when required by the code official. The landscape plan shall include devel- opment and maintenance requirements for the vegetation management zone adjacent to structures and roadways, and provide significant fire hazard reduction benefits for public and firefighting safety.
603.3.1 Contents. Landscape plans shall contain the following: 1. Delineation of the 30-foot (9144 mm) and 100-foot (30 480 mm) fuel management zones from all structures. 2. Identification of existing vegetation to remain and proposed new vegetation. 3. Identification of irrigated areas. 4. A plant legend with both botanical and common names, and identification of all plant material symbols. 5. Identification of ground coverings within the 30-foot (9144 mm) zone.
603.4 Vegetation. All new vegetation shall be fire-smart vegetation in accordance with this section.
Exception: Trees classified as nonfire-smart vegetation complying with Section 603.4.2.1.
To be considered fire-smart vegetation, vegetation must meet at least one of the following: 1. Be identified as fire-smart vegetation in an approved book, journal or listing from an approved organization. 2. Be identified as fire-smart vegetation by a licensed landscape architect with supporting justification. 3. Plants considered fire-smart vegetation and approved by the local enforcing agency.
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.
CWUIC § 6-3 High relevance — show source text
2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE 6-3
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FIRE PROTECTION REQUIREMENTS
602.3.2 Final fire protection plan. Final fire protection plan shall include items listed in Section 602.3.1 and the following: 1. A map identifying all proposed plants in the fuel modification zones with a legend that includes a symbol for each proposed plant species. The plan shall include specific information on each species proposed, including but not limited to: 1.1. The plant life-form;
1.2. The scientific and common name; and
1.3. The expected height and width for mature growth. 2. Identification of irrigated and nonirrigated zones. 3. Requirements for vegetation reduction around emergency access and evacuation routes. 4. Identification of points of access for equipment and personnel to maintain vegetation in common areas. 5. Legally binding statements regarding community responsibility for maintenance of fuel modification zones. 6. Legally binding statements to be included in covenants, conditions and restrictions regarding property owner responsibili- ties for vegetation maintenance.
SECTION 603— VEGETATION PLAN
603.1 General. Planting of vegetation for new landscaping shall be selected to reduce vegetation in proximity to a structure and to maintain vegetation as it matures.
603.2 Application. All new plantings of vegetation in State Responsibility Area (SRA) and Local Responsibility Areas (LRA) designated as a Fire Hazard Severity Zone shall comply with Sections 603.3 through 603.4.2.1.
603.3 Landscape plans. Landscape plans shall be provided when required by the code official. The landscape plan shall include devel- opment and maintenance requirements for the vegetation management zone adjacent to structures and roadways, and provide significant fire hazard reduction benefits for public and firefighting safety.
603.3.1 Contents. Landscape plans shall contain the following: 1. Delineation of the 30-foot (9144 mm) and 100-foot (30 480 mm) fuel management zones from all structures. 2. Identification of existing vegetation to remain and proposed new vegetation. 3. Identification of irrigated areas. 4. A plant legend with both botanical and common names, and identification of all plant material symbols. 5. Identification of ground coverings within the 30-foot (9144 mm) zone.
603.4 Vegetation. All new vegetation shall be fire-smart vegetation in accordance with this section.
Exception: Trees classified as nonfire-smart vegetation complying with Section 603.4.2.1.
To be considered fire-smart vegetation, vegetation must meet at least one of the following: 1. Be identified as fire-smart vegetation in an approved book, journal or listing from an approved organization. 2. Be identified as fire-smart vegetation by a licensed landscape architect with supporting justification. 3. Plants considered fire-smart vegetation and approved by the local enforcing agency.
CWUIC § 1270.01 High relevance — show source text
FIRE-RESISTANCE-RATED CONSTRUCTION. The use of materials and systems in the design and construction of a building or structure to safeguard against the spread of fire within a building or structure and the spread of fire to or from buildings or structures to the wildland-urban interface area.
FIRE-SMART VEGETATION. Plants, shrubs, trees and other vegetation that exhibit properties, such as high moisture content, little accu- mulation of dead vegetation and low sap or resin content, that make them less likely to ignite or contribute heat or spread flame in a fire than native vegetation typically found in the region.
( Note: The following sources contain examples of types of vegetation that can be considered as fire-smart vegetation: Fire-resistant Plants for Home Landscapes, A Pacific Northwest Extension publication; Home Landscaping for Fire, University of California Division of Agriculture and Natural Resources; Sunset Western Garden Book.)
[BG] FLAME SPREAD INDEX. A comparative measure, expressed as a dimensionless number, derived from visual measurements of the spread of flame versus time for a material tested in accordance with ASTM E84 or UL 723.
FUEL. Any combustible material, including petroleum-based products, cultivated landscape plants, grasses, weeds and wildland vegetation.
FUEL BREAK (applicable to CCR, Title 14 provisions only). A strategically located area where the volume and arrangement of vegetation has been managed to limit fire intensity, fire severity, rate of spread, crown fire potential and/or ember production. [CCR Title 14 §1270.01(n)]
FUEL MODIFICATION. A method of modifying fuel load by reducing the amount of nonfire-smart vegetation or altering the type of vegetation to reduce the fuel load.
FUEL MOSAIC. A fuel modification system that provides for the creation of islands and irregular boundaries to reduce the visual and ecological impact of fuel modification.
FUEL-LOADING. The oven-dry weight of fuels in a given area, usually expressed in pounds per acre (lb/a) (kg/ha). Fuel-loading may be referenced to fuel size or time-lag categories, and may include surface fuels or total fuels.
GREEN BELT (applicable to CCR, Title 14 provisions only). Open space, parks, wildlands, other areas or a combination thereof, as desig- nated by Local Jurisdictions, which are in, surround or are adjacent to a city or urbanized area, that may function as Fuel Breaks and where Building construction is restricted or prohibited. [CCR Title 14 §1270.01(o)]
GREENWAYS (applicable to CCR, Title 14 provisions only). Linear open spaces or corridors that link parks and neighborhoods within a community through natural or manmade trails and paths. [CCR Title 14 §1270.01(p)]
HAMMERHEAD/T (applicable to CCR, Title 14 provisions only). A “T” shaped, three-point turnaround space for fire apparatus on a road or driveway, being no narrower than the road or driveway that serves it. [CCR Title 14 §1270.01(q)]
CWUIC § 1299.04 High relevance — show source text
of defensible space clearance shall be maintained in two distinct “Zones” as follows: “Zone 1” extends thirty_ feet (30 ft.) out from each “Building or Structure,” or to the property line, whichever comes first; “Zone 2” extends from thirty feet (30 ft.) to one hundred feet (100 ft.) from each “Building or Structure,” but not beyond the property line. The vegetation treatment requirements for Zone 1 are more restrictive than for Zone 2, as provided in (a) and (b) below. The Department of Forestry and Fire Protection's “Prop- erty Inspection Guide, 2000 version, April 2000,” provides additional guidance on vegetation treatment within Zone 1 and Zone 2, but is not mandatory and is not intended as a substitute for these regulations. (a) Zone 1 Requirements: (1) Remove all dead or dying grass, plants, shrubs, trees, branches, leaves, weeds, and pine needles from the Zone whether such vegetation occurs in yard areas around the “Building or Structure,” on the roof or rain gutters of the “Building or Structure,” or any other location within the Zone. (2) Remove dead tree or shrub branches that overhang roofs, below or adjacent to windows, or which are adjacent to wall surfaces, and keep all branches a minimum of ten feet (10 ft.) away from chimney and stovepipe outlets. (3) Relocate exposed firewood piles outside of Zone 1 unless they are completely covered in a fire resistant material. (4) Remove flammable vegetation and items that could catch fire which are adjacent to or under combustible decks, balco- nies and stairs.
(b) Zone 2 Requirements: (1) In this zone create horizontal and vertical spacing among shrubs and trees using the “Fuel Separation” method, the “Continuous Tree Canopy” method or a combination of both to achieve defensible space clearance requirements. Further guidance regarding these methods is contained in the State Board of Forestry and Fire Protection's, “General Guidelines for Creating Defensible Space, February 8, 2006,” incorporated herein by reference, and the “Property Inspec- tion Guide” referenced elsewhere in this regulation. (2) In both the Fuel Separation and Continuous Tree Canopy methods the following standards apply: (A) Dead and dying woody surface fuels and aerial fuels shall be removed. Loose surface litter, normally consisting of fallen leaves or needles, twigs, bark, cones, and small branches, shall be permitted to a maximum depth of three inches (3 in.). (B) Cut annual grasses and forbs down to a maximum height of four inches (4 in.). (C) All exposed wood piles must have a minimum of ten feet (10 ft.) of clearance, down to bare mineral soil, in all directions.
(c) For both Zones 1 and 2: (1) “Outbuildings” and Liquid Propane Gas (LPG) storage tanks shall have the following minimum clearance: ten feet (10 ft.) of clearance to bare mineral soil and no flammable vegetation for an additional ten feet (10 ft.) around their exterior. (2) Protect water quality. Do not clear vegetation to bare mineral soil and avoid the use of heavy equipment in and around streams and seasonal drainages. Vegetation removal can cause soil erosion, especially on steep slopes. Keep soil distur- bance to a minimum on steep slopes.
1299.04 Additional clearance.
CWUIC § 4.1 Medium relevance — show source text
2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE APPENDIX A-5
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APPENDIX A—GENERAL REQUIREMENTS
A105.3 Explosives. Explosives shall not be possessed, kept, stored, sold, offered for sale, given away, used, discharged, transported or disposed of within wildland-urban interface areas, except by permit from the code official.
A105.4 Combustible materials. Outside storage of combustible materials such as, but not limited to, wood, rubber tires, building materials or paper products shall comply with the other applicable sections of this code and this section. A105.4.1 Individual piles. Individual piles shall not exceed 5,000 square feet (465 m [2] ) of contiguous area. Piles shall not exceed 50,000 cubic feet (1416 m [3] ) in volume or 10 feet (3048 mm) in height.
A105.4.2 Separation. A clear space of not less than 40 feet (12 192 mm) shall be provided between piles. The clear space shall not contain combustible material or nonfire-smart vegetation.
SECTION A106—DUMPING
A106.1 Waste material. Waste material shall not be placed, deposited or dumped in wildland-urban interface areas or in, on or along trails, roadways or highways or against structures in wildland-urban interface areas .
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:
- In the hearth of an established fire pit, camp stove or fireplace.
- 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.
- 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.
CWUIC § 1.11. Medium relevance — show source text
- The California Code of Regulations (CCR), Title 19, Division 1 provisions that are found in the California Wildland-Urban Interface Code are a reprint from the current CCR, Title 19, Division 1 text for the code user’s convenience only. The scope, applicability and appeals procedures of CCR, Title 19, Division I remain the same. The state agency does not adopt sections identified by the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.
The California Code of Regulations (CCR), Title 14, Division 1.5 provisions that are found in the California Wildland-Urban Interface Code are not listed in the Matrix Adoption Tables as they are not within the State Fire Marshal’s authority to adopt. These provisions are a reprint from the current CCR, Title 14, Division 1.5 text for the code user’s convenience only and are identified in the body of the code by square brackets containing references to applicable Title 14 sections.
2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE APPENDIX F-1
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APPENDIX F-2 2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE
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F CHARACTERISTICS OF FIRE-SMART VEGETATION
This appendix is for informational purposes and is not intended for adoption.
User notes:
About this appendix: Appendix F is an informational appendix provided for the convenience of the code user. It is simply a compilation of the eight characteristics of fire-smart vegetation that can be used effectively within wildland-urban interface areas to reduce the likelihood of fire spread through vegetation.
SECTION F101—GENERAL
F101.1 Characteristics of fire-smart vegetation. All plants will burn under extreme fire weather conditions, such as drought. However, plants burn at different intensities and rates of consumption. Fire-smart plants burn at a relatively low intensity, slow rates of spread and with short flame lengths. The following are characteristics of fire-smart vegetation:
- Growth with little or no accumulation of dead vegetation (either on the ground or standing upright).
- Nonresinous plants (willow, poplar or tulip trees).
- Low volume of total vegetation (for example, a grass area as opposed to a forest or shrub-covered land).
- Plants with high live fuel moisture (plants that contain a large amount of water in comparison to their dry weight).
- Drought-tolerant plants (deeply rooted plants with thick, heavy leaves).
- Stands without ladder fuels (plants without small, fine branches and limbs between the ground and the canopy of overtopping shrubs and trees).
- Plants requiring little maintenance (slow-growing plants that, when maintained, require little care).
- Plants with woody stems and branches that require prolonged heating to ignite.
2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE APPENDIX F-3
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APPENDIX F-4 2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE
CWUIC § 2-3 Medium relevance — show source text
EXTERIOR WALL COVERING. A material or assembly of materials applied on the exterior side of exterior walls for the purpose of providing a weather-resisting barrier, insulation or for aesthetics, including but not limited to veneers, siding, exterior insulation and finish systems, rainscreen systems, architectural trim, and embellishments such as cornices, soffits, facias, gutters and leaders.
[F] FIRE CHIEF. The chief officer or the chief officer’s authorized representative of the fire department serving the jurisdiction.
2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE 2-3
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DEFINITIONS
FIRE CODE OFFICIAL. The fire chief or other designated authority charged with the administration and enforcement of the California Fire Code, or a duly authorized representative.
FIRE FLOW CALCULATION AREA. The floor area, in square feet (square meters), used to determine the adequate water supply.
FIRE HAZARD SEVERITY ZONES. Geographical areas designated pursuant to California Public Resources Codes, Sections 4201 through 4204 California Government Code, Sections 51175 through 51189.
The map, approved by the Office of the State Fire Marshal, is hereby incorporated by reference and entitled “State Responsibility Area Fire Hazard Severity Zones,” dated September 29, 2023.
FIRE PROTECTION PLAN. A document prepared for a specific project or development proposed for the wildland-urban interface area. It describes ways to minimize and mitigate potential for loss from wildfire exposure.
FIRE WEATHER. Weather conditions favorable to the ignition and rapid spread of fire. In wildfires, this generally includes high temperatures combined with strong winds and low humidity. See “Critical fire weather.”
FIRE-RESISTANCE-RATED CONSTRUCTION. The use of materials and systems in the design and construction of a building or structure to safeguard against the spread of fire within a building or structure and the spread of fire to or from buildings or structures to the wildland-urban interface area.
FIRE-SMART VEGETATION. Plants, shrubs, trees and other vegetation that exhibit properties, such as high moisture content, little accu- mulation of dead vegetation and low sap or resin content, that make them less likely to ignite or contribute heat or spread flame in a fire than native vegetation typically found in the region.
( Note: The following sources contain examples of types of vegetation that can be considered as fire-smart vegetation: Fire-resistant Plants for Home Landscapes, A Pacific Northwest Extension publication; Home Landscaping for Fire, University of California Division of Agriculture and Natural Resources; Sunset Western Garden Book.)
[BG] FLAME SPREAD INDEX. A comparative measure, expressed as a dimensionless number, derived from visual measurements of the spread of flame versus time for a material tested in accordance with ASTM E84 or UL 723.
FUEL. Any combustible material, including petroleum-based products, cultivated landscape plants, grasses, weeds and wildland vegetation.
FUEL BREAK (applicable to CCR, Title 14 provisions only). A strategically located area where the volume and arrangement of vegetation has been managed to limit fire intensity, fire severity, rate of spread, crown fire potential and/or ember production. [CCR Title 14 §1270.01(n)]
CWUIC § 1.11. Medium relevance — show source text
Additionally, make sure you have 10 feet (3048 mm) of clearance_ around your wood piles. 9. Fences—remove or relocate all vegetation, combustibles and combustible debris adjacent to and underneath fences. 10. Replace wood mulch products within five feet (1524 mm) of all structures with noncombustible products such as dirt, stone, or gravel. 11. Remove all dead or dying grass, plants, shrubs, trees, branches, leaves, weeds, and pine needles within 30 feet (9144 mm) of all structures or to the property line. 12. Be sure to store combustible outdoor furnishings away from your home when not in use. 13. Remember to properly store retractable awnings and umbrellas when not in use so they do not collect leaves and embers.
APPENDIX G-4 2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
CALIFORNIA WILDLAND-URBAN INTERFACE CODE – MATRIX ADOPTION TABLE
APPENDIX H – REFERENCED CALIFORNIA DOCUMENTS
(Matrix Adoption Tables are nonregulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)
(Not adopted by the State Fire Marshal)
Adopting Agency BSC BSC-
CGSFM Col5 HCD Col7 Col8 DSA Col10 OSHPD Col12 Col13 Col14 Col15 Col16 BSCC DPH AGR DWR CEC CA SL SLC Adopting Agency BSC BSC-
CGT-24 T-19* 1 2 1/AC AC SS 1 1R 2 3 4 5 5 5 5 5 5 5 5 5 Adopt Entire Chapter Adopt Entire Chapter as
amended (amended sections
listed below)Adopt only those sections that
are listed below[California Code of Regulations,
Title 19, Division 1]Chapter / Section - The California Code of Regulations (CCR), Title 19, Division 1 provisions that are found in the California Wildland-Urban Interface Code are a reprint from the current CCR, Title 19, Division 1 text for the code user’s convenience only. The scope, applicability and appeals procedures of CCR, Title 19, Division I remain the same. The state agency does not adopt sections identified by the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.
CWUIC § A107 Medium 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:
- In the hearth of an established fire pit, camp stove or fireplace.
- 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.
- 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 § F101 Medium relevance — show source text
SECTION F101—GENERAL
F101.1 Characteristics of fire-smart vegetation. All plants will burn under extreme fire weather conditions, such as drought. However, plants burn at different intensities and rates of consumption. Fire-smart plants burn at a relatively low intensity, slow rates of spread and with short flame lengths. The following are characteristics of fire-smart vegetation:
- Growth with little or no accumulation of dead vegetation (either on the ground or standing upright).
- Nonresinous plants (willow, poplar or tulip trees).
- Low volume of total vegetation (for example, a grass area as opposed to a forest or shrub-covered land).
- Plants with high live fuel moisture (plants that contain a large amount of water in comparison to their dry weight).
- Drought-tolerant plants (deeply rooted plants with thick, heavy leaves).
- Stands without ladder fuels (plants without small, fine branches and limbs between the ground and the canopy of overtopping shrubs and trees).
- Plants requiring little maintenance (slow-growing plants that, when maintained, require little care).
- Plants with woody stems and branches that require prolonged heating to ignite.
2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE APPENDIX F-3
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
APPENDIX F-4 2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
CALIFORNIA WILDLAND-URBAN INTERFACE CODE – MATRIX ADOPTION TABLE
APPENDIX G – VOLUNTARY HOME HARDENING RECOMMENDATIONS
(Matrix Adoption Tables are nonregulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)
Adopting Agency BSC BSC-
CGSFM Col5 HCD Col7 Col8 DSA Col10 OSHPD Col12 Col13 Col14 Col15 Col16 BSCC DPH AGR DWR CEC CA SL SLC Adopting Agency BSC BSC-
CGT-24 T-19* 1 2 1/AC AC SS 1 1R 2 3 4 5 5 5 5 5 5 5 5 5 Adopt Entire Chapter X Adopt Entire Chapter as
amended (amended sections
listed below)Adopt only those sections that
are listed below[California Code of Regulations,
Title 19, Division 1]Chapter / Section
Frequently asked questions
Can I plant any tree if I keep it pruned?
Yes — but if the species is nonfire‑smart, you must meet one of the two options in § 603.4.2.1: either the mature drip line is ≥ 30 ft from the building or the drip line is ≥ 10 ft and the tree is maintained and well pruned to prevent rapid fire transmission § 603.4.2.1 .
How do I measure the required distances — from trunk or drip line?
Measure clearance from the drip line (the outer edge of the canopy) to the structure when the code specifies drip‑line distances (e.g., § 603.4.2(1) and § 603.4.2.1) and use trunk-to-structure + canopy radius arithmetic when planning placement .
Are small shrubs allowed right up to the house if they’re maintained?
No — shrub groupings must be separated from structures by 30 ft per § 603.4.1(4). Individual groundcovers and specific exceptions can be addressed in landscape plans and local enforcement, but the grouping/30‑ft rule applies to new shrub plantings .
Who decides whether a plant is “fire‑smart”?
The code allows three routes in § 603.4: an approved listing, a licensed landscape architect’s identification with justification, or approval by the local enforcing agency. Use Appendix F for informational guidance on typical characteristics of fire‑smart plants file.
If I already have existing nonfire‑smart trees, do I have to remove them?
The code requires trimming/clearance actions (for example 10 ft from chimneys per § 603.4.2(3)) and maintenance of defensible space (see § 604); removal is not automatic but enforcing agencies may require fuel modification or removal depending on hazard and local rules file.
More in California Wildland-Urban Interface Code
- Administration and Definitions
- Board of Appeals, Administration & Enforcement (permits, code official duties, appeals process)
- Wildland‑Urban Interface Area Designation & Mapping
- Fire Service Access & Water Supply (fire apparatus roads, driveways, hydrants, draft sites, standby power)
- Wildland‑Urban Interface Area Requirements (access, water, premises identification, key boxes)
- Referenced Standards & Test Methods
- Special Building Construction Regulations (ignition‑resistant construction, roof/vent/assembly requirements)
- Appendices and Model Ordinances (vegetation plans, severity‑zone adoption, home‑hardening guidance)
- Fire Protection Requirements (fire protection plans, systems, safety element provisions)
- Referenced California Documents & Matrix (CCR/Title 14 & 19 cross‑references, statutory references)
- Vegetation Management & Defensible Space (vegetation plans, maintenance, fire‑smart characteristics)
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