CWUIC · California Wildland-Urban Interface Code

Shrub planting limits, group size and spacing near structures

Q: Do the numeric distances in § 603.4.1 apply to existing plantings or only to new plantings?

§ 603.4.1 specifically applies to all new plantings of shrubs ; the section text shown applies to new plantings. For existing vegetation, consult § 604 (maintenance of defensible space) and your local AHJ for enforcement and remediation guidance .

Q: How is “aggregate diameter” measured?

The text of § 603.4.1 states the 10‑ft aggregate diameter limit but does not provide a measurement procedure in the retrieved text. Ask your local code official how they measure (common practice: maximum overall width of the contiguous planting) .

Q: If my shrubs are fire‑smart species, can they be larger than 6 ft?

No — § 603.4.1(1) sets 6 ft (1829 mm) as the maximum height for all new shrub plantings. Other sections (e.g., Appendix F on fire‑smart vegetation) describe desirable plant characteristics but do not change the numeric limits in § 603.4.1 .

Summary: The CWUIC § 603.4.1 requires new shrubs to be no taller than 6 ft, keeps shrub clusters to a maximum 10 ft across, requires at least 15 ft between clusters and 30 ft from structures, and demands tree branches above shrubs be high enough (three times the shrub height or 10 ft). Confirm measurement method and any local interpretations with your code official.

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Last reviewed: July 6, 2026

What the code requires

All new shrub plantings must meet the size and spacing limits in § 603.4.1 of the California Wildland‑Urban Interface Code. In plain English: individual shrubs must remain low, shrub clusters are limited in maximum aggregate size, clusters must be spaced apart and kept well away from structures, and shrubs under trees must not create ladder fuels by being too tall beneath low branches. See § 603.4.1 for the controlling text .

Keep shrubs short, keep shrub clusters small and separated, and keep them far enough from buildings — those four limits are the heart of § 603.4.1.

Requirements in detail

Core numeric limits (from § 603.4.1)

Maximum shrub height: 6 feet (1829 mm). § 603.4.1(1)
Maximum shrub grouping (aggregate) diameter: 10 feet (3048 mm). § 603.4.1(2)
Minimum separation between shrub groupings: 15 feet (4572 mm). § 603.4.1(3)
Minimum separation from structures: 30 feet (9144 mm). § 603.4.1(4)
Shrubs below or within a tree’s drip line: the lowest tree branch must be at least three times the height of the understory shrubs or 10 feet (3048 mm), whichever is greater. § 603.4.1(5)

Decision table — quick reference

Decision / Dimension	Required value	Code Reference
Maximum individual shrub height	6 ft (1829 mm)	§ 603.4.1(1)
Max aggregate diameter of a shrub grouping	10 ft (3048 mm)	§ 603.4.1(2)
Min horizontal separation between shrub groupings	15 ft (4572 mm)	§ 603.4.1(3)
Min horizontal separation from structures	30 ft (9144 mm)	§ 603.4.1(4)
Minimum clearance for shrubs under/within a tree drip line	≥ 3 × shrub height OR 10 ft (3048 mm), whichever greater	§ 603.4.1(5)

How to interpret the terms (what the code does — and does not — specify)

The code text in § 603.4.1 lists the numeric limits above but does not define a formal measurement procedure for “aggregate diameter” or exactly how to measure from structures (e.g., edge‑to‑edge vs. centerline). The section provides the numeric requirements only; measurement conventions are not specified in the retrieved text of § 603.4.1 .
Because § 603.4.1 does not provide detailed measurement rules, confirm measurement method with the local code official (authority having jurisdiction) when precise clearance planning is needed.

Exceptions & special cases

The plain text of § 603.4.1 (the controlling section provided in the CWUIC) does not list any exceptions to the shrub height, grouping, spacing or tree‑drip‑line rule; all new shrub plantings must comply with the bullet limits in § 603.4.1 as written .
Related provisions govern trees and nonfire‑smart vegetation (see § 603.4.2 and § 603.4.2.1) and may impose additional planting or clearance rules where trees are present; consult those sections for tree‑specific rules .
Where the code text is silent on a measurement method or a local condition (for example, planting next to irregularly shaped structures, retaining walls, or steep slopes), the code official’s interpretation and local amendments control.

Common mistakes

Assuming “aggregate diameter” means total planted area rather than the maximum width of the contiguous cluster — the code gives a 10 ft aggregate diameter limit; check with the AHJ on how they measure it (edge‑to‑edge is frequently used in practice) .
Planting shrubs taller than 6 ft (either at planting or allowing them to grow beyond the limit) — maintenance to keep shrubs at or below 6 ft (1829 mm) is required by § 603.4.1(1) .
Creating clusters whose combined spread exceeds 10 ft, or locating clusters less than 15 ft apart — both are explicit limits in § 603.4.1(2)–(3) .
Placing shrubs within 30 ft of a structure (for example, planting at the foundation line or in a planting bed that comes closer than 30 ft) — that violates § 603.4.1(4) .
Forgetting ladder‑fuel risk: planting shrubs under tree canopies without ensuring the lowest branch is high enough (minimum 3× shrub height or 10 ft) can create a continuous fuel path — § 603.4.1(5) addresses this .

Worked example — step‑by‑step scenario

Scenario: You are siting a small privacy planting near the rear of a house. You plan three shrubs that mature to 4 ft tall and that will be planted close enough that their canopies touch.

Shrub height check: planned mature height = 4 ft → below 6 ft limit, so height is OK per § 603.4.1(1) .
Grouping size check: if the three‑plant cluster forms a roughly circular contiguous planting whose maximum overall width (aggregate diameter) is 8 ft, that is ≤ 10 ft and complies with § 603.4.1(2) . If instead the contiguous cluster spans 12 ft, it exceeds the 10 ft limit and must be reduced or split.
- Note: § 603.4.1(2) gives the numeric 10 ft limit but does not define the precise measurement method; confirm whether your AHJ measures the maximum overall width (common practice) or uses another convention .
Separation from other groupings: any other shrub cluster must be at least 15 ft away from this cluster per § 603.4.1(3) .
Separation from the house: the outer edge of this cluster must be located so that the cluster is at least 30 ft from the structure per § 603.4.1(4). If the house wall is 25 ft away from the planting location, you must move or reduce the planting to meet the 30 ft rule.
Tree drip line clearance: if this planting sits under a mature tree’s drip line and the shrubs are 4 ft tall, the lowest tree branch must be at least 3 × 4 ft = 12 ft above the shrubs (since 12 ft > 10 ft), per § 603.4.1(5). If the branch is currently only 8 ft above the shrubs, pruning (or moving/removing shrubs) is required to meet the code.

Related provisions

§ 603.4.2 — Trees (planting and clearance rules for trees near structures) .
§ 603.4.2.1 — Nonfire‑smart vegetation (additional controls for certain tree species) .
§ 603.3 and § 603.3.1 — Landscape plans and required contents (vegetation plan documentation) .
§ 604 — Maintenance of defensible space (ongoing fuel management requirements) .
Definitions (Chapter 2) — consult the CWUIC definitions for any defined terms used in § 603.4.1 (e.g., drip line, defensible space) — see the code’s definitions chapter for authoritative meanings .

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.

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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 § 4.10.1. Medium relevance — show source text
4.10.1. General Requirements

When establishing new overhead services, and/or when building or remodeling structures near high-voltage lines, poles, or towers, applicants must research planting regulations and follow the rules established here.

N OTE : Applicants must consider safety and access for repairs when planting near an overhead electric service.

A. Where required, applicants must establish clearances as described in

California Public Resource Code (PRC) Division 4, “Forests, Forestry and Range and Forage Lands,” Part 2, Chapter 3, Section 4292. PG&E can exempt applicants if the vegetation around power poles at the completed construction site will be well irrigated, low growing, and not highly flammable in perpetuity. In general, do not plant trees near power poles or

towers.

B. For electric distribution, low-voltage and high-voltage lines rated up to 60,000 volts, applicants must establish a 15-foot “low-growth” zone on both sides of all new lines. Applicants also must ensure that all branches with potential overhang within 4 feet of the conductors are trimmed.

Applicants must not plant trees under or within 15 feet of distribution power poles. Applicants should landscape with low-growth, fire-resistant plants, shrubs, and flowers in the zone under electric power lines. PG&E recommends planting shrubs and flowers in low-growth zones to ensure compliance. Figure 4-40, “Illustration of 15-Foot Clearance, Low-Growth Zone,” on Page 4-28, and Figure 4-41, “Grass and Shrubs Recommended Under Service Wires,” on Page 4-29, illustrate low-growth zones and show how the 15-foot clearance is measured from the center of the pole.

C. For all electric transmission, high-voltage lines rated greater than 60,000 volts, applicants must not plant trees within the right-of-way easement of the transmission poles or towers. Applicants must follow a “no-growth” zone inside rights-of-way areas, including under the electric power lines. The zone outside the rights-of-way areas is a “low-growth” zone, tree-planting zone, and/or a shrub-and-flower planting zone. Figure 4-41, “Grass and Shrubs Recommended Under Transmission Wires,” on Page 4-29, illustrates a no-growth zone.

4-27 2022 – 2023

Section 4, Electric Service: Overhead

4.10.1. (continued)

D. Applicants must ensure that a thorough inspection is made of proposed construction areas. Dead, dying, diseased, or hazard trees tall enough to fall into the proposed power lines must be removed. Hazard trees are defined as any tree having a structural defect that may cause the tree, or a portion of the tree, to fall either on someone or on something of value.

Figure 4-40 Illustration of a 15-Foot Clearance, Low-Growth Zone

F

2022 – 2023 4-28

Section 4, Electric Service: Overhead
California Wildland-Urban Interface Code Medium relevance — show source text
***** This document is not in the printed manual and is available only in the online version of

the Greenbook on www.pge.com/greenbook.

Applicants should access PG&E’s Internet website at www.pge.com/greenbook to find the latest versions of, and updates to, these documents. Also, applicants may contact their local PG&E service planning offices to ensure their documents are current.

N OTE : See Table FM-1, “Service Planning Office and Inspection Desk Contact

Information,” at the front of this manual starting on Page iv, for specific contact numbers listed by area.

Applicants should refer to PG&E’s Community Wildfire Safety Program Guide to Landscaping in High Fire-Threat Areas (included on the following two pages) for updated guidance on extending the defensible space around your property, specifically around power lines. Following this guidance could help save both real estate and lives.

B−1 2022 – 2023

Appendix B: Electric and Gas Service Documents

2022 – 2023 B−2

Appendix B: Electric and Gas Service Documents

B−3 2022 – 2023

Appendix B: Electric and Gas Service Documents

2022 – 2023 B−4

Appendix B: Electric and Gas Service Documents

B−5 2022 – 2023

Appendix B: Electric and Gas Service Documents

Tree Planting Matrix Table s

Applicants should not plant trees either under or adjacent to power lines. IF applicants decide to plant trees or shrubs on their properties, attached is a list of low-growing, fire-resistant vegetation to consider for ground cover near facilities.

Table B-1 through Table B-6 list trees that are suitable for planting near ( not adjacent to or under ) power lines. The trees are listed by genus and species in each table. The list is limited and does not include all suitable trees; however, applicants can use this information as a guideline for choosing an appropriate tree for planting near power lines. The basic rule of thumb is to choose plants that grow to be 25 feet or less at maturity. For additional suggestions about appropriate trees, consult with nurseries, certified arborists, gardening books, and websites like SelecTree at http://ecologycenter.org/directory/directory−entries/selectree/ (maintained by the Urban Forest Ecosystems Institute at Cal Poly State University, San Luis Obispo).

PG&E urges applicants to consider planting shrubs, grasses, and flowers near and under power lines. By selecting low-growing vegetation, applicants ensure that trimming back intrusive growth is not an issue.

2022 – 2023 B−6

Appendix B: Electric and Gas Service Documents

Table B-1 Plant Matrix for Stockton, Yosemite, Fresno, and Kern Divisions [1]

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.

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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- CG	SFM	Col5	HCD	Col7	Col8	DSA	Col10	OSHPD	Col12	Col13	Col14	Col15	Col16	BSCC	DPH	AGR	DWR	CEC	CA	SL	SLC
Adopting Agency	BSC	BSC- CG	T-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 § 08-15 Medium relevance — show source text

All shrubs should be planted at a minimum 5 gallon size.
Refer to the climate zone map in the Sunset New Western Garden Book for the climate zone in your area.

Plants (shrubs)	Climatic Zones	Col3	Col4	Col5	Col6
Plants (shrubs)	Zone 1	Zone 7	Zone 8	Zone 9	Zone 14
Plants (shrubs)	Cold Climate, High Elevation, Snow All Year, Frost All Year, High Mountain, Area	Warm Climate, Hot Summer, Mild Winters, Low Elevations, Foothill Area	Warm Climate, Cold-Air Basins In Winter, Low Elevations, Hot, Dry Summers, Cool Winter	Hot Climate, Within Thermal Belt, Warmer and Higher Elevations than Zone 8, Foothill Areas	Warm Climate, Low Elevation, Hot and Dry Summers, Mainly Inland Valley Areas
Arctostaphylos “Hookeri” (Monterey Manzanita)	−	X	−	−	X
Arctostaphylos “Emerald Carpet” (Manzanita)	−	X	−	−	X
Arctostaphylos “Uva Ursi” (Bearberry)	−	X	−	−	X
Caenothus G.H. “Yankee Point” (Yankee Point Ceanothus)	−	X	−	−	X
Nandina Domestica (Heavenly Bamboo)	−	X	X	X	X
Agapanthus Orientalis (Lily-of-the-Nile)	−	X	X	X	X
Santolina Chamaecyparissus (Lavender Cotton)	X	X	X	X	X
Cistus Hybridus (White Rockrose)	−	X	X	X	−
Cistus Purpureus (Purple Rockrose)	−	X	X	X	−
Raphiolepis I. “Coates Crimson” (Indian Hawthorn)	−	−	X	X	X
Raphiolepis I. “Enchantress” (Indian Hawthorn)	−	−	X	X	X
Eriophyllum Confertiflorum (Yellow Yarrow)	X	X	X	X	X
Juniperus Conferta (Shore Juniper)	X	X	X	X	X
Rosemarinus Officinalus (Creeping Rosemary)	−	−	X	X	X

Rev. #04: 08-15-17 063422 Page 7 of 12

Greenbook Landscape Screen for Pad-Mounted Transformers

Plant Matrix for San Francisco, Peninsula, and DeAnza Divisions

Notes

All shrubs are evergreen plants not over 5 feet at maturity.
All shrubs should be planted at a minimum 5 gallon size.

California Wildland-Urban Interface Code Medium relevance — show source text

Appendix B: Electric and Gas Service Documents

Tree Planting Matrix Table s

Applicants should not plant trees either under or adjacent to power lines. IF applicants decide to plant trees or shrubs on their properties, attached is a list of low-growing, fire-resistant vegetation to consider for ground cover near facilities.

Table B-1 through Table B-6 list trees that are suitable for planting near ( not adjacent to or under ) power lines. The trees are listed by genus and species in each table. The list is limited and does not include all suitable trees; however, applicants can use this information as a guideline for choosing an appropriate tree for planting near power lines. The basic rule of thumb is to choose plants that grow to be 25 feet or less at maturity. For additional suggestions about appropriate trees, consult with nurseries, certified arborists, gardening books, and websites like SelecTree at http://ecologycenter.org/directory/directory−entries/selectree/ (maintained by the Urban Forest Ecosystems Institute at Cal Poly State University, San Luis Obispo).

PG&E urges applicants to consider planting shrubs, grasses, and flowers near and under power lines. By selecting low-growing vegetation, applicants ensure that trimming back intrusive growth is not an issue.

2022 – 2023 B−6

Appendix B: Electric and Gas Service Documents

Table B-1 Plant Matrix for Stockton, Yosemite, Fresno, and Kern Divisions [1]

Botanical Name Genus and Species	Common Name	Evergreen vs. Deciduous	Height and Spread (in feet)	Drought Tolerant	Special Considerations	Climate Zones 2
Acer buergeranum	Trident Maple	D	25 s	No	Low spreading growth, red to yellow fall color.	4‐9, 14‐16, 20, 21
Acer palmatum	Japanese Maple	D	25 h	No	Green leaf varieties tolerate sun best, fire resistance favorable.	1‐9, 14‐24
Cercis canadensis	Eastern Redbud	D	25‐40 h 3	No	Small rosy pink flowers in early spring, is easily killed by over‐watering.	1‐3, 7‐20
Cotinus coggygria `prupurea'	Smoke Tree	D	25 h	—	Branches droop but resist breakage, full sun, dramatic puffs of purple to lavender from fading flowers.	1‐24
Crataegus laevigata	English Hawthorn	D	25 h 15 s	—	Thorny branches, need pruning to thin out excess twiggy growth, bright rose to red flowers.	1‐11, 14‐17
Koelreuteria paniculata `Kew' or` Fastigiata'	Golden Rain Tree	D	25 h	No	Branches susceptible to breakage,

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.

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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:
1. Growth with little or no accumulation of dead vegetation (either on the ground or standing upright).
2. Nonresinous plants (willow, poplar or tulip trees).
3. Low volume of total vegetation (for example, a grass area as opposed to a forest or shrub-covered land).
4. Plants with high live fuel moisture (plants that contain a large amount of water in comparison to their dry weight).
5. Drought-tolerant plants (deeply rooted plants with thick, heavy leaves).
6. Stands without ladder fuels (plants without small, fine branches and limbs between the ground and the canopy of overtopping shrubs and trees).
7. Plants requiring little maintenance (slow-growing plants that, when maintained, require little care).
8. Plants with woody stems and branches that require prolonged heating to ignite.
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APPENDIX F-4 2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE
CWUIC § 3-3 Medium relevance — show source text
301 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3

302 Wildland-Urban Interface Area Designations . . . . . .3-3

CHAPTER 4 WILDLAND-URBAN INTERFACE AREA

REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . 4-3

401 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3

402 Applicability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3

403 Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3

404 Water Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-7

CHAPTER 5 SPECIAL BUILDING CONSTRUCTION

REGULATIONS . . . . . . . . . . . . . . . . . . . . . . . . 5-3

501 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-3

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
CWUIC § 403.2 Medium relevance — show source text
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Access Applicability 402 Driveways 403.2 Fire apparatus access roads 403.3 Grade 403.7

Individual structures 402.2 Marking of roads 402.3, 403.4 Restricted 403.1

Subdivisions 402.1 Accessory Buildings and Miscellaneous Structures

Defined 202

Detached 504.11 Exempt from permit 105.3 Additions or Alterations 101.5

Address Markers 402.3 Agriculture 202 Alternative Materials or Methods 104.2.2

Appeals 112 Appendices 101.2.1 Applicable Building 202 Applicability 102 Approved 202 Approved Agency 104.2.2.6.1, 202 Authority of Code Official 104

Building 202 Building Official 202

Certificate of Completion 111 Certificate of occupancy 111.2 Revocation 111.4

Temporary occupancy 111.3

Code Official 202 Code Official, Authority 104 Community Wildland-Urban Interface (WUI) Fire Hazard Evaluation Framework Appendix C Compliance Alternatives 105 Construction Documents 106

Amended 106.10

Examination of 106.9 Information on plans and specifications 106.2 Phased 106.12

Previous approval 106.11 Retention of 106.8 Site plan 106.3 Vegetation management plans 106.4 Control of Storage Appendix A, A105 Critical Fire Weather 202

Dead-end Road 202 Defensible Space 403, 601.3 Vegetation Plan 603 Definitions 202 Designation of Wildland-Urban Interface Area 302.1

Director 202 Driveway 202 Dumping Appendix A, A106 Dwelling 202

Exterior Covering 202

INDEX

Fees 109 Findings of Fact Appendix E Fire Chief 202 Fire Danger Rating System Appendix D Fire Flow Calculation Area Application 404.5 Defined 202 Fire Hazard Severity Zones 1.1.2, 202, 302.1, 302.2, Appendix D, Appendix H Fire Protection Plans 602

Fire Weather 202

Fire-Resistance-Rated Construction 501.3 Fire-Resistive Vegetation Appendix F Fire-Retardant-Treated Lumber or

Wood 503.2, 504.5, 504.7, 504.11 Flame Spread Index 202 Flashing 504.2.1, 504.5.1 Fuel Break 202, 609 Fuel Models Appendix D Fuel Modification 202

Fuel Modification Distance 603.2

Fuel Mosaic 202 Fuel-Loading 202

General Requirements Appendix A Green Belt 202

Greenways 202
CWUIC § 2325P-01 Medium relevance — show source text
The PG&E field inspector must verify that the poles meet the dimensional and test requirements for reused poles. These requirements are described in PG&E Procedure TD-2325P-01, “Inspecting, Reinforcing, and Reusing Wood Poles.”

If installing overhead temporary services, refer to Numbered Document 025055, found in Appendix C.

2022 – 2023 4-26

Section 4, Electric Service: Overhead

4.10. Required Vegetation Clearances

The state of California requires electric utilities to keep electric lines (i.e., high-voltage lines) cleared of vegetation. All newly constructed distribution lines and existing lines must meet these requirements.

N OTE : PG&E may determine that the distribution line should be installed underground, or that trees should be removed, if the planned line extension does not meet or exceed the clearance requirements between existing trees and overhead electric lines. See new options for commercial agricultural orchards in Subsection 4.10.5. on Page 4-31.

4.10.1. General Requirements

When establishing new overhead services, and/or when building or remodeling structures near high-voltage lines, poles, or towers, applicants must research planting regulations and follow the rules established here.

N OTE : Applicants must consider safety and access for repairs when planting near an overhead electric service.

A. Where required, applicants must establish clearances as described in

California Public Resource Code (PRC) Division 4, “Forests, Forestry and Range and Forage Lands,” Part 2, Chapter 3, Section 4292. PG&E can exempt applicants if the vegetation around power poles at the completed construction site will be well irrigated, low growing, and not highly flammable in perpetuity. In general, do not plant trees near power poles or

towers.

B. For electric distribution, low-voltage and high-voltage lines rated up to 60,000 volts, applicants must establish a 15-foot “low-growth” zone on both sides of all new lines. Applicants also must ensure that all branches with potential overhang within 4 feet of the conductors are trimmed.

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

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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- CG	SFM	Col5	HCD	Col7	Col8	DSA	Col10	OSHPD	Col12	Col13	Col14	Col15	Col16	BSCC	DPH	AGR	DWR	CEC	CA	SL	SLC
Adopting Agency	BSC	BSC- CG	T-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

CWUIC § 1505.1.2 Medium relevance — show source text

1
1505.1.2||||||| |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| |601|General|Y||||||||| |601.1|Scope|Y||||||||| |601.2|Objective|Y|||4901.1|||||| |601.3|Chapter 6 definitions|Y||||||1299.02(a)||| |602|Fire protection plans|Y|||4903|||||| |602.1|General|Y|||4903.1|||||| |602.2|Contents|Y|||4903.2|||||| |602.3|Project information|Y|||4903.2.1|||||| |602.3.1|Preliminary fire
protection plan|Y|||4903.2.1.1|||||| |602.3.2|Fire protection plan|Y|||4903.2.1.2|||||| |603|Vegetation plan|Y|||4906|||||| |603.1|General|Y|||4906.1|||||| |603.2|Application|Y|||4906.2||||51182(a)|| |603.3|Landscape plans|Y|||4906.3|||||| |603.3.1|Contents|Y|||4906.3.1||3.07(b)(2)||51182(a)|4291| |603.4|Vegetation|Y|||4906.4||||||

APPENDIX H-30 2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE

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

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.

Frequently asked questions

Do the numeric distances in § 603.4.1 apply to existing plantings or only to new plantings?

§ 603.4.1 specifically applies to all new plantings of shrubs; the section text shown applies to new plantings. For existing vegetation, consult § 604 (maintenance of defensible space) and your local AHJ for enforcement and remediation guidance .

How is “aggregate diameter” measured?

The text of § 603.4.1 states the 10‑ft aggregate diameter limit but does not provide a measurement procedure in the retrieved text. Ask your local code official how they measure (common practice: maximum overall width of the contiguous planting) .

If my shrubs are fire‑smart species, can they be larger than 6 ft?

No — § 603.4.1(1) sets 6 ft (1829 mm) as the maximum height for all new shrub plantings. Other sections (e.g., Appendix F on fire‑smart vegetation) describe desirable plant characteristics but do not change the numeric limits in § 603.4.1 .

What if a shrub cluster currently violates the spacing rules?

Because § 603.4.1 gives the spacing limits for new plantings and § 604 addresses maintenance and defensible space, remediation is typically required — contact your local code official for a compliance plan (removal, thinning, or relocation) and timing requirements .

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Tree planting, crown spacing and pruning requirements within the 30‑foot zone

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Core numeric limits (from § 603.4.1)

Decision table — quick reference

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Worked example — step‑by‑step scenario

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F CHARACTERISTICS OF FIRE-SMART VEGETATION

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