HomeMy WebLinkAbout10/7/2025 Item 8a, Tuggle - Staff Agenda CorrespondenceCity of San Luis Obispo, Council Memorandum
City of San Luis Obispo
Council Agenda Correspondence
DATE: October 7th, 2025
TO: Mayor and Council
FROM: Todd Tuggle, Fire Chief
VIA: Whitney McDonald, City Manager
SUBJECT: ITEM 8a - WILDLAND URBAN INTERFACE (WUI) CODE, BUILDING
HARDENING, AND DEFENSIBLE SPACE REGULATIONS
Staff received the following questions, regarding Wildland Urban Interface (WUI) Code,
Building Hardening, and Defensible Space Regulations. The questions are below with
staff’s response shown in italics:
1. Can we obtain from CAL FIRE the individual model layers of the FHSZ maps as shown
in the video "Methods for Creating Fire Hazard Severity Zone Maps" at this website?
The individual GIS layers used in the model to develop the zones are available in the
“Science and Method” section of the CAL FIRE FHSZ website. This section includes
a document outlining the various model input data sources, with hyperlinks directing
users to the authoritative data providers. An important note is that model layers are
not readily accessible and the specific model settings are not disclosed. As a result,
City GIS staff cannot replicate the methodology CAL FIRE applied to produce the final
zones. Here is the direct link to the FHSZ Model Input Data Sources document.
2. Have the new FHSZ maps been put into the City GIS system? Can they be added as
a layer in the parcel viewer?
City staff have included the FHSZ layers on the City of San Luis Obispo web site
parcel viewer. The Fire Hazard Severity Zones are viewable via this link. Please note
that the FHSZ layers are turned off in the application by default , but can be turned on
by clicking the “eye” icon in the map layers column. A screenshot has been provided
for reference.
Item 8a.WUI Code, Building Hardening, and Defensible Space Regulations Page 2
3. Since upgrades to existing homes, like the removal of flammable trees in close
proximity to residences, will be costly, are there any reimbursements (state or local)
or recommendations for lower-cost contractors?
The WUI Code does not include a specific code requirement for the removal of existing
trees (including Non-Fire Smart trees), only the requirement for maintenance thereof.
The City is NOT advocating for or advising to remove otherwise healthy trees.
Property owners are required to maintain the trees currently on their properties.
Should property owners choose to remove Non-Fire Smart trees (such as Junipers or
fibrous palms), there is currently no General Fund budget to reimburse property
owners for defensible space work on their properties. Staff will continue to seek
external resources to support defensible space work in the community, and as recently
as September 2025, the City applied for a grant to support a pilot project wherein a
community-based organization/s could perform defensible space work for low-income
and otherwise vulnerable community members.
4. How can the City advocate to the state for financial support to help offset costs borne
by residents and the local community?
The City has and will continue to advocate for its residents at the state level. In
anticipation of the new FHSZ maps, Council expanded the City’s 2025 Legislative
Advocacy Platform to include new sections supporting funding for wildfire -mitigation
and defensible-space efforts. Through its partnership with the League of California
Cities (Cal Cities), the City continues to engage with legislators and state agencies to
promote policies that reduce local cost burdens, enhance program flexibility, and
ensure new wildfire-resilience requirements are practical and equitable.
Consistent with these priorities, the City submitted letters of support for bills including
AB 1 and AB 888, which strengthen insurance fairness and provide funding for
defensible-space and home-hardening projects. Cal Cities has also helped advance
related legislation (AB 1143, SB 326, SB 616) to improve statewide wildfire -risk
mapping and community-level resilience standards, all of which are now on the
Governor’s desk for final action. As the Board of Forestry and Fire Protection finalizes
new Zone Zero regulations, Cal Cities is closely monitoring the rulemaking process,
alongside fire chiefs and local gover nment partners. Their advocacy focuses on
ensuring that defensible-space regulations are practical, science-based, and
coordinated with local inspection capacity. Should Council direct staff to do so, the
City could also submit feedback directly to the Boa rd of Forestry and Fire Protection
to provide our local perspective during the final rulemaking process.
Item 8a.WUI Code, Building Hardening, and Defensible Space Regulations Page 3
5. What deadlines for existing homes in the new high -severity zone are you
contemplating for the commencement of ordinances & fines, so we have time to plan
and pay for?
The only part of the 2025 WUI code that applies to existing buildings is defensible
space requirements, which only apply in the Very High Fire Hazard Severity Zone.
Defensible space requirements under Government Code §51182 have applied to
properties in the VHFHSZ since adoption of the new FHSZ maps in July. The WUI
code will become effective on January 2, 2026. These regulations will impose
vegetation maintenance requirements upon the areas within 30 feet of an existing
building (“Zone 1”) and within 30-100ft from the building (“Zone 2.”) Staff recommend
leading with education and using a complaint-based approach to enforcement. This
means that if the Fire Department receives a complaint that vegetation is not compliant
with state code on a particular property, a Fire Department inspector would visit the
property. Staff recommend starting the enforcement process with education and a
warning.
The forthcoming Zone 0 requirements, which are currently in draft form on the state
level, are anticipated to take effect on January 2, 2029 . Zone 0 requirements, which
focus on creating an ember resistant zone in the five feet closest to a structure, would
go into effect immediately for new construction and new plantings, but existing
buildings would have 3 years to come into compliance (expected date is currently
January 2, 2029). Staff recommend enforcing Zone 0 like other defensible space
requirements. Existing trees within Zone 0 shall be maintained so that there are no
dead or dying branches. All live tree branches shall be maintained five feet above the
adjacent building or structure’s roof, ten feet away from chimneys and stovepipes and
five feet away from the sides of any building or structure. There is also an exception
for single species of trees that are well pruned and maintained so as to effectively
manage fuels and fuel ladders.
The Fire Department will work with community members to understand the importance
of defensible space and help prioritize actions property owners can take before Zone
0 defensible space requirements come into effect for existing buildings in early 2029.
The Fire Department will not seek to penalize property owners, but to help people
better understand their risks and help property owners implement critical mitigations
that will reduce the impacts of future wildfire exposures. These actions also help
improve the potential for fire response personnel to safely fight a wildfire on the
property and take defensive fire actions. Making a home safe for fire response is a
critical action that can help protect the home, family, and community.
Item 8a.WUI Code, Building Hardening, and Defensible Space Regulations Page 4
6. Are we to assume that when San Luis Obispo develops its own defensible space
requirements, all existing properties in addition to new buildings and remodels within
very high and high fire severity zones must conform to the new defensible space
requirements?
Staff are not currently recommending adoption of a local defensible space ordinance.
Chapter 6 of the WUI Code, effective January 2 , 2026, requires compliance with
defensible space standards within the Very High Fire Hazard Severity Zones only.
Staff is recommending taking an “as-is" approach to the adoption of the WUI Code,
meaning that staff is not recommending additional measures added to the WUI Code
specific to SLO.
7. The staff reports says that no particular inspection protocol is required per
Government Code. What does the Government Code require in terms of
enforcement? What triggers the requirement for the City to enforce the defensible
space provisions?
The enforcement approach by local agencies is largely discretionary. If defensible
space violations exist on a property within a VHFHSZ, the Government Code requires
that the City notify the owner of the property to correct the conditions. The Government
Code allows (but does not require) cities to then correct the violation (s) if the property
owner fails to do so, at the owner’s expense (see Govt. Code 51186). The penalties
prescribed by the Government Code for defensible space violations are criminal
(infractions and misdemeanors; see Govt. Code 51185). Staff’s intention is to clarify
that, upon adoption of the WUI Code, defensible space violations will be enforced
administratively (i.e. through notices to correct and, if necessary, administrative
citations and fines) rather than criminally.
8. What is the status of the local hazard mitigation plan update? Is the update being
coordinated with the proposed changes to the WUI code?
Currently the County of San Luis Obispo Mitigation Plan is awaiting approval from
FEMA and upon that approval will be adopted by the County. Once that adoption is
completed, the City's Local Hazard Mitigation Plan (annex G of the County Multi-
Jurisdiction Hazard Mitigation Plan) will be sent to Council for adoption.
The new Local Mitigation Plan does not reflect any WUI code changes due to it being
submitted prior to the publication of the new Fire Code and WUI Code. If there are
substantial changes needed to the City’s Local Hazard Mitigation Plan, those changes
can be made after adoption of the Local Mitigation Plan. Due to the current status of
the County’s plan, no changes can be made at this time and will have to be amended
after the current plan is adopted.
Item 8a.WUI Code, Building Hardening, and Defensible Space Regulations Page 5
The CalFire Fire Severity Zone Map is mentioned in the City’s Local Hazard Mitigation
Plan (G.3.311 Wildfire) and acknowledges the increase in properties and critical
facilities in the updated hazard severity zones.
9. Will the City update the 2019 Community Wildfire Protection Plan (CWPP)? Has the
effectiveness of the CWPP been evaluated since adoption? Has the CWPP lowered
insurance rates in the City?
The CWPP published in 2019 was a broad strategic level document that tied the City
of SLO into the larger Countywide CWPP. The 2019 CWPP, however, did not have
any prescriptive treatments elucidated in it. Recognizing this shortcoming, staff
focused on a Citywide Vegetation Management Plan which was funded in the Spring
of 2025 through the Coastal Conservancy. The kick-off meeting was held Friday
October 3rd, with estimated completion by summer of 2026. Staff intend to update the
2019 CWPP when the Vegetation Management Plan is completed. Incorporation of
the Vegetation Management Plan into the CWPP will provide for a more relevant and
holistic document applicable specifically to SLO.
It is unclear if the CWPP has any impacts on insurance rates. The Safer from Wildfires
initiative states that Firewise Communities and the Fire Risk Reduction Community
List are the two community level mitigation factors that have an impact on insurance
rates, but each insurance company will factor them separately. The City of San Luis
Obispo is on the current Fire Risk Reduction Community List with the State Board of
Forestry and Fire Protection.
10. Can you provide additional details on how the City will incentivize and support the
creation of Firewise communities?
Currently the Fire Department works with neighborhood groups /HOAs to meet and
discuss the requirements for establishing a Firewise Community. Neighborhood walks
to discuss defensible space, vegetation management, and how to establish a Firewise
board for the neighborhood are conducted with the Emergency Manager and Fire
Marshal. Upon establishing a Firewise Community, the City will provide signage
indicating the neighborhood’s status as meeting the requirements and being in
compliance with Firewise regulation.
11. For the new fire-safe tree requirement with a minimum dripline of 30 feet from
residences, does this effectively mean no new trees in developments with
typical urban lot sizes? Additionally, the guideline for maintaining 10 feet around all
outbuildings down to bare soil seems particularly challenging in residential settings.
Item 8a.WUI Code, Building Hardening, and Defensible Space Regulations Page 6
Per Section 603.4.2, new trees that are planted within 30 feet of a structure in the
VHFSZ shall be planted and maintained so that the tree’s dripline (the outer edge of
the canopy) is located 10 feet away from the structure. In addition, new trees that are
planted adjacent to other trees are to be planted where the crowns of the trees are at
least 10 feet from one another. Residentially zoned parcels, for example, require
between a 10-20-foot front yard setback. Based on these setback requirements, at
least one tree could be planted in the front yard. Additionally, existing healthy trees
that are maintained and free of dead and dying material are supported in with Zones
0,1, and 2. Trees within the zones may not extend over the roof and must be at least
10 feet from a stovepipe or chimney.
In addition, the public right-of-way provides additional space away from structures that
can support street trees. The City requires that a minimum of one street tree be
installed and established for any commercial building permit or residential building
permit that adds a dwelling unit to a site, unless the City Arborist determines that the
site cannot accommodate a new tree. In an effort to continue to support planting new
trees, the City Arborist has put together a list of fire smart trees that have smooth bark,
narrower and more vertical canopies that can be easily maintained to the minimum
10-foot clearance from structures and while drought tolerant, can benefit from
additional irrigation. The list can be accessed here..
An outbuilding per the code is a structure that is less than one hundred-twenty (120)
square feet in size and not used for human habitation . As noted in the question, a
minimum clearance of 10-feet down to bare soil is required around the outbuilding.
This is because the outbuilding is not required to comply with the same standards as
a structure and is likely more combustible. A property owner has the option to remove
vegetation 10 feet from the structure (and replace removed vegetation with non-
combustible materials like DG or gravel) or consider removing the structure.
12. For properties in the VHFHSZ, does this imply that homeowners will need to remove
all trees within the 30-foot range to comply? Since that's 30' to drip line, do es that
effectively mean some trees 50'+ away may need to be removed to be compliant? The
defensible space diagrams also raise some concerns, as they don’t appear to align
well with the realities of lot sizes within the city.
Homeowners do not have to remove all trees within the 30-foot range of an applicable
building. The different zones—Zone 0 (forthcoming), Zone 1, and Zone 2—are
intended to reduce the amount of combustible vegetation around homes. Trees are
allowed in the different zones, as long as they are well maintained and the presence
of ladder fuels (ground level vegetation) is managed to prevent fire from entering the
tree canopy, and more broadly to prevent fire moving from open spaces into the built
environment.
Item 8a.WUI Code, Building Hardening, and Defensible Space Regulations Page 7
Zone 1 (5’-30’), Modifying Zone, is designed to reduce the likelihood of fire burning
directly to the structure. Modifying fuels in this zone creates discontinuity between
plant groups, which limits pathways for fire to burn to the structure. An existing tree
that is nonfire-smart may exist within the 30-foot modifying zone as long as the limbs
are well pruned and maintained. A new tree would need to be planted and maintained
so that, at maturity, it remains at least 10 feet from a combustible structure. In addition
to the maintenance of the tree, dead and dying surface fuels, such as fallen leaves or
needles, would need to be reduced or removed to prevent a fire path from the tree to
the structure.
13. Is there an opportunity to adopt a "yes, and" approach to these regulations? While we
must and should meet legal obligations, could we advocate against an "all plants burn"
stance that might exacerbate urban heat concerns and diminish shade in
neighborhoods?
Urban extreme heat, biodiversity, and neighborhood aesthetics are all concerns that
must be balanced with defensible space measures for communities in fire prone
areas, such as SLO. Staff acknowledges that an “all plants burn” viewpoint is
counterproductive to longstanding tree planting efforts and the City’s larger goals for
climate action and resilience.
Staff are always seeking better suited arboreal choices when interacting with private
property owners and when making management decisions related to City -owned
property. The WUI code requires that new plantings use species and location
placements that reduce the risk of combustion. Not all trees are ideal for urban and
open space environments, and certain species can have deleterious environmental
impacts while also posing a serious fire threat. Where existing trees pose significant
risks, they must be maintained to protect community safety, as required by the WUI
code.
There is ample evidence, however, that many trees are locally adapted to fire
conditions in their native environments. The WUI code further encourages these fire-
adapted plants and trees in SLO. For instance, in the Board of Forestry guide to
defensible space, there is language describing maintenance of continuous canopies
on WUI properties. In these configurations, there are recommendations for
maintaining continuous canopy while reducing the ladder fuels below the canopy to
prevent potential “crown” fires. Continuous tree canopies of fire smart species can
cool urban heat islands and improve the aesthetics of our neighborhoods, as long as
the ground level growth below the canopies is properly maintained to remove ladder
fuel potential.
Item 8a.WUI Code, Building Hardening, and Defensible Space Regulations Page 8
14. Why wouldn’t we consider recommending inspections upon sale as an alternative
compliance mechanism? Is this mostly to stay in the voluntary compliance realm?
The High and Very High FHSZs have expanded greatly within the City with adoption
of the new maps this summer. The City could require inspections upon sale of
properties within the Very High and/or High FHSZs. However, it is staff’s
recommendation to approach the expanded applicability of defensible space
requirements with outreach and education, rather than mandatory inspections, until
our community and staff become more familiar with the regulations. Requiring
inspections upon sale would trigger the docume ntation requirements of AB 38, which
may serve as a barrier to home sales, so close consultation with property owners and
real estate professionals would be essential before moving toward an inspection -
upon-sale/AB38 program. In terms of staffing resources involved with an inspection-
upon-sale program, inspections would require a signature from a “badged” member
of the Fire Department (a full-time employee), rather than an intern, as the Fire
Department intends to utilize for voluntary inspections. Whereas a voluntary
inspection form would be designed to provide recommendations, an official inspection -
upon-sale inspection would identify violations, and a seller would remain out of
compliance with AB38 until they fixed any outstanding defensible space violati ons on
the property, which again may delay home sales.
15. Given increasing fire hazards in San Luis Obispo, what is the City planning to do to
manage hazardous fuels on City Open Space properties, as well as streets and
evacuation routes? Could you share a plain-English summary of the work, a simple
map of where it will happen, how it’s funded, and when it starts?
The City has maintained City open space properties to reduce hazardous fuels for
decades and will continue to dedicate City resources to reduce wildfire risks in the
WUI. These maintenance activities include routine mowing and grazing, invasive
species removal, fuel break creation and maintenance, and strategic thinning. These
activities are accomplished through Ranger Service and Open Space Technicians and
in partnership with CAL Fire and the SLO Fire Safe Council. Though not required, per
Government Code 51184, these activities are consistent with adopted property-
specific conservation plans, general plan policy, and the forthcoming Open Space
Vegetation Management Plan expected in 2026.
However, in light of increasing wildfire risks and the related need to build additional
capacity, staff are actively seeking external resources to expand hazardous fuel
treatments in the WUI. As of the time of this correspondence, staff have submitted
four grant applications with state and federal agencies to accomplish various aspects
of planned fuel treatments:
a. Community Wildfire Defense Grant with U.S. Forest Service
b. Wildfire Prevention Grant with CAL FIRE
c. Wildfire Resilience Grant with State Coastal Conservancy
d. Grazing Infrastructure Grant with Wildlife Conservation Board
Item 8a.WUI Code, Building Hardening, and Defensible Space Regulations Page 9
Furthermore, to maintain clearance on roadways and evacuation routes, the City’s
Public Works Urban Forestry Maintenance staff prunes trees to maintain clearance.
The City targets a pruning cycle of approximately every 5 -years. Some areas (like
downtown) or other specific trees are pruned more often (every 3 years). It is important
to note that, at locations outside of City jurisdiction that are not City-owned properties,
the City relies on private property owners and partnerships with CAL FIRE and the
SLO Fire Safe Council to accomplish fuel treatments and evacuation route
maintenance.
The City will continue to communicate with the public about planned vegetation
management activities, including physical signage, digital notices, community
workshops, and in-person neighborhood meetings by request.
16. Would any of the alternatives listed on pages 20 -22 reduce costs and/or enhance
livability for City residents?
The alternatives to adopting the WUI code as -is listed on pages 20-22 include:
adopting more restrictive building standards (Alternative 1), expanding designated
WUI areas (Alternative 2), and adopting supplemental appendices regarding Fire
Protection Methods (Alternative 3) and/or Vegetation Management Plan
Requirements (Alternative 4). None of these requirements are anticipated to reduce
costs or enhance livability for City residents. Conversely, adopting more restrictive
building standards or expanding designated WUI areas would likely lead to increased
costs for property owners and greater regulatory burdens.
17. How would these code changes affect development of housing, especially affordable
housing on San Luis Ranch Lot 7?
All new housing in the City will have to comply with the building construction and
hardening standards in Chapter 5 of the WUI Code. This Chapter addresses things
like building materials, roof type, deck construction, requirement for dual-pane
windows, etc. New development of housing in the Very High Fire Hazard Severity
Zone will also need to comply with the Defensible Space requirements outlined in
Chapter 6 of the WUI. These regulations have the potential to make construction more
expensive. According to a study by Headwaters Economics, a nonpartisan research
nonprofit, in northern and southern California, building a wildfire-resistant home in
2022 with Chapter 7A requirements and a noncombustible zone around the home (0
to 5 feet) increased construction costs by approximately $2,800 over the Baseline
home. Compliance with all chapters of the WUI will take place during plan review and
inspection of a project. San Luis Ranch Lot 7 is not located in a Very High Fire Hazard
Severity Zone, so the Chapter 6 regulations would not apply, however, the building
construction and hardening standards of Chapter 5 would apply , as they will apply
citywide.
Item 8a.WUI Code, Building Hardening, and Defensible Space Regulations Page 10
18. When will the draft Zone 0 requirements be finalized? How would they apply to very
dense housing developments with wooden fencing closer than 5 feet to homes, such
as in San Luis Ranch?
The latest draft regulations to implement Government Code section 51182, published
by the Board of Forestry and Fire Protection on September 22, 2025, introduces an
additional zone—Zone 014. As the WUI Code references and requires compliance
with Section 1299.03, by adopting the WUI Code, the City will also adopt, by reference,
the Zone 0 requirements as issued by the state (including any future amendments).
The Zone 0 requirements are anticipated to take effect on January 1, 2026, for new
structures, and on January 1, 2029, for existing structures.
It is important to keep in mind that Zone 0 regulations, along with all defensible space
requirements, only apply to parcels within the VHFHSZ. No homes within San Luis
Ranch are within a VHFHSZ.
For parcels that are within the VHFHSZ, all defensible space requirements (including
Zone 0 regulations) will extend to the zone boundary (5 feet [Zone 0], 30 feet [Zone
1], or 100 feet [Zone 2]), or the property line, whichever is closer. Based on the draft
Zone 0 regulations, no new wood/combustible fencing can be constructed within 5
feet of a structure within a VHFHSZ . However, existing fencing touching a structure
within a VHFHSZ will need to be replaced within the three year “grace period” for
existing structures.
Following the study session, the City will launch a public information effort based on
the City’s Public Engagement and Noticing Manual to help property owners
understand and comply with new and existing statewide requirements for defensible
space and home hardening in recently adopted FHSZs, based on the new WUI Code.
The public information plan will focus on ensuring that homeowners, business owners,
and community partners clearly understand their responsibilities under the State’s
WUI Code, including the new Zone Zero regulations once they are finalized by the
state. Public outreach tools will include digital communications, direct mail, print
materials, events and informational meetings, media and advertising, and outreach
through trusted communitybased organizations and industry partners.
19. Could evaluation of Potential Local Amendments to the State WUI code be postponed
and later considered at the same time as the General Plan Safety Element update?
Staff are not recommending local amendments to the State WUI Code at this time.
Staff must amend the General Plan Climate Adaptation and Safety Element (CASE)
to reflect the new fire hazard maps, as required by Government Code §65302.
Separately, staff have proposed, as a Strategic Next Step, to agendize a study session
to re-evaluate the CASE’s current prohibition on subdivisions within the VHFHSZ. If
directed by Council, staff will return with a discussion of potential local amendments
to the state WUI Code for Council’s consideration during this subsequent study
session.