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Fire Codes

Marin County Fire agencies and jusrisdictions each adopt and amend a fire code. Many codes relate to new construction or remodels and, some are listed here for reference. Some Fire agencies have adopted stricter codes and it is important to check with your local fire and building departments before planning a remodel or new construction project.  Fire codes establish minimum standards for the protection of life and property by increasing the ability of a building to withstand the effect of a wildfire, and therefore contribute to a systematic reduction in wildfire losses.

Wildfire code enforcement in Marin County is conducted by a variety of County, local, state, and federal agencies, including fire departments and diustrict sand local and county planning and building agencies.


Below are a quick reference to general Fire Codes and Standards in Marin County.  These Codes and Standards vary by property location and jurisdiction, so please refer to the fire agency or municipality responsible for your location for specific details.

There are two key elements to WUI fire codes: (1) defensible space clearance that must be upkept continuously, and (2) building standards for new construction. In both cases the minimum standards outlined in the state code only require these codes to be enforced in SRA and Very High Fire Hazard Severity Zones in the LRA. Local jurisdictions can increase the extent of the standards if they choose. The suite of codes are well outlined in the California Fire Code Chapter 49. The chapter outlines refers readers to other codes. A summary of Chapter 49 and it’s referenced codes is described in this appendix, and includes links to the full code language. 

California Fire Code Chapter 49 Requirements for Wildland-Urban Interface Fire Areas

Adopted frequently. Current code last adopted in 2016. 

The code defines state responsibilities, maps, and plans, and calls out sections of different codes that must be met. The code calls out two key sections: 

  1. Section 4905 Wildfire Protection Building Construction
    1. Refers readers to comply with three specific elements of the California Building Standards Code. The Code applies to State Responsibility Areas, and in Local Responsibility Areas where “substantial evidence in the record [shows] that the requirements of this section are necessary for effective fire protection.”
      1. California Building Code, Chapter 7A. 
      2. California Residential Code, Section R327. 
      3. California Referenced Standards Code, Chapter 12-7A. 
  2. Section 4906 Hazardous Vegetation and Fuel Management
    1. Mandates that all Fire Hazard Severity Zones (Moderate, High, and Very High) in the SRA, and Very High Severity Zones in the LRA are required to comply with the following code requirements.
      1. i. Public Resources Code, Section 4291 
      2. California Code of Regulations, Title 14, Division 1.5, Chapter 7, Subchapter 3, Section 1299. 
      3. California Government Code, Section 51182 
      4. California Code of Regulations, Title 19, Division 1, Chapter 7, Subchapter 1, Section 3.07. 
    2. For SRA only
      1. 1. Public Resources Code 4290 
      2. California Code of Regulations, Title 14, Division 1.5, Chapter 7, Subchapter 2, Section 1270 
    3. For LRA only
      1. Government Code 51175 - 51189 
California Building Code 7A 

Applies to properties permitted after December 1, 2005. 

Applies to building materials, systems, and/or assemblies used in the exterior design and construction of new buildings located within a Wildland-Urban Interface Fire Area – defined as all SRA lands, and Very 

High Fire Hazard Severity Zones in the LRA (which is supported by Government Code Sections 51177(c), 51178, and 5118). The code has requirements for the following building elements. Within each section there are further references to specific standards. 

  1. Roofing 
  2. Attic ventilation 
  3. Exterior walls 
  4. Underfloors (decking, floors) 
  5. Ancillary buildings and structures 
California Residential Code Section R327 

Adopted regularly 

All requirements apply to buildings built after July 1, 2008. Some (roof and attic ventilations sections) apply to buildings built after December 1, 2005. 

The code reads similar to California Building Code 7A and focuses on materials and construction methods for exterior wildfire exposure. This code includes Section R372.3 which describes the specific building and material standards for testing. This code includes the same sections described in California Building Code 7A but expands within each section and includes an additional subsection on windows and doors. 

California Referenced Standards Code, Chapter 12-7A 

Goes into much greater detail than both CRC Section R327 and CBC 7A. It provides greater detail into the fire resistant testing standards for materials and building components. 

Public Resources Code (PRC) 4291 

Adopted in 2009. 

Requirements apply to buildings built after January 1, 2010. 

The code primarily focuses on defensible space requirements for property owners. In addition to defensible space requirements is states that new construction, including a building damaged by a fire, be built to standards outlined by Government Code Section 51189. It also makes the Department of Forestry and Fire Protection responsible for the development and maintenance of fuels management guidance. 

California Code of Regulations, Title 14, Division 1.5, Chapter 7, Subchapter 3, Article 3, Section 1299. 

Provides guidance for the implementation of PRC 4291 to increase the survivability of buildings that exist with the SRA. It outlines a the specific set of defensible space requirements for two zones: 

  1. Zone 1 – Applies to area within 30 feet of a building. 
  2. Zone 2 – Applies to area between 30 and 100 feet of a building. 
  3. Additional defensible space beyond 100 feet can be required, but cannot require clearance beyond the property line. 
California Code of Regulations, Title 19, Division 1, Chapter 7, Subchapter 1, Section 3.07. 

Focuses on required clearances. No combustible material shall be placed within 10 feet of any building, and reiterates (more succinctly) the defensible space requirements in Subchapter 3. 

Public Resources Code (PRC) 4290

Adopted June 1989 

Requires properties permitted after 1990 to meet the following regulations: 

  1. Road standards for fire equipment access. 
  2. Standards for signs identifying streets, roads, and buildings. 
  3. Minimum private water supply reserves for emergency fire use. 
  4. Fuel breaks and greenbelts. 
  5. *these regulations do not supersede local regulations which equal or exceed minimum regulations by the state. 
California Code of Regulations, Title 14, Division 1.5, Chapter 7, Subchapter 2, Section 1270 

The regulations have been in effect since September 1, 1991. 

Provides the minimum wildfire protection standards for buildings and development in the SRA. The code has requirements for the following sections. It also grants the responsible fire agency/department to inspect for compliance with the regulations. 

  1. Emergency access – regulations for road width, supportive of surface loads, grades, turnarounds and turnouts, and driveways. 
  2. Signing and building numbering – regulations for roads and properties. 
  3. Private water supply reserves for emergency fire use – regulations for quantities and locations of water supplies, with details for hydrants and valves 
  4. Vegetation modification – reiterates the defensible space regulations with an additional section on the use of greenbelts for subdivision plans. 
Government Code 51175 – 51189 

Outlines many of the already described regulations. The code describes the procedural process for designated local areas as Very High Fire Hazard Severity and set the original designation date as January 1, 1995 for all Bay Area counties, and by January 1, 1996 for all CA counties. The code calls for the VHFHSZ designation in LRA to be updated every five years and when possible coincide with general plan updates [Note, this has not been updated every five years]. The code also requires property owners to disclose during transfers of the property (1102.6a and 1103.2 Civil Code) that it is in the VHFHSZ. 

California Government Code, Section 51182 

Is specific to defensible space regulations. Violations of regulation are punishable by a fine between $100-500 for the first infraction, $250-$500 for the second infraction, and greater than $500 and charged with a misdemeanor for the third infraction. The local agency can also contract the necessary defensible work space and place the expenses as a lien on the property. 

Links to Full Code Text 

CFC Chapter 49




CRC Section R327 


CRSC Chapter 12-7a 


PRC 4290 & 4291 



California Code of Regulations, Title 14, Division 1.5, Chapter 7, Subchapter 3, Article 3, Section 1299. 


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


California Code of Regulations, Title 14, Division 1.5, Chapter 7, Subchapter 2, Section 1270 


Government Code 51175 – 51189 



FIRESafe MARIN offers a variety of resources for homeowners looking to reduce wildfire hazards and protect their family and property.

Defensible Space Information

Defensible space is essential to improve your home’s chance of surviving a wildfire. It’s the buffer you create between a building on your property and the grass, trees, shrubs or any wildland area that surround it. This space is needed to slow or stop the spread of wildfire and it protects your home from catching fire – either from direct flame contact or radiant heat. Defensible space is also important for the protection of the firefighters defending your home.  Click here to learn more about creating defensible space...

Shaded Fuel Breaks


One of the more common vegetation management practices is the creation of shaded fuel breaks, which are a carefully planned thinning of dense tree cover and the removal of underlying brush. These are placed in strategic locations along a ridge, access road, or other location such as around a subdivision.

The objective of a shaded fuel break is to reduce, modify, and manage fuels within designated areas in order to enhance mitigation efforts in the event of a wildland fire situation. A shaded fuel break does not remove all vegetation in a given area.

A shaded fuel break provides more fire protection and improves forest health.  Fuel breaks are generally constructed to separate communities and clusters of communities from the native vegetation, in order to protect both the developing area and the adjacent wildlands. They are most commonly found along ridgelines where fire control efforts are focused.

The most advantageous location and design must be individually determined after considering fuels, topography, weather, exposures and other constructed or planned improvements. Soil stabilization, erosion prevention measures and long-term maintenance requirements must receive thorough consideration during the planning and construction phase.

Shaded Fuel Breaks

A modified shaded fuel break is defined as a defensible location, where fuels have been modified, that can be used by fire suppression resources to suppress oncoming wildfires. Any fuel break by itself will NOT stop a wildfire. It is a location where the fuel has been modified to increase the probability of success for fire suppression activities. Ground resources can use the location for direct attack or firing out. Air resources can use the location for fire retardant drops. The public and fire resources can use the location for more efficient ingress and egress.

Shaded fuel breaks act as strategic "defensible landscape" to reduce fire speed and severity, improve suppression by ground crews and air attack. The purposes of strategic fuel modification are to separate communities or groups of structures from the native vegetation and break up large expanses of flammable fuel into smaller blocks, all with the purpose of reducing fire loss and damage.

A fuel break is a strip or block of land on which the native vegetation has been permanently reduced and/or modified so that fires burning around it can be more readily and safely controlled. Fuels within fuel breaks are reduced in volume through thinning or pruning, or are changed to vegetative types which burn with a lower intensity and offer less resistance to fire control efforts.

Fuel breaks are intended to correct two conditions that have limited the effectiveness of fire control: the difficulty of quick, safe staffing of critical line locations when needed and the need for widening many fire breaks before they can be used effectively. Fuel breaks are not expected to control a fire in themselves, but provide points of access to facilitate control of the flanks and provide possible backfire action in the face of an advancing fire head.

A fuel break system may utilize existing road systems. Most fuel breaks include roadways for vehicle access, or other continuous strips cleared to mineral soil, which serve as a barrier to the spread of fire through the fine fuels or as a line from which to backfire.

A few homes with defensible space may make little difference when the neighborhood is threatened by a wide flame front.  While defensible space addresses the need to remove the fuels close to individual structures, vegetation management focuses on programs that address such methods as shaded fuel breaks and other fuel modification practices on the broader landscape.

Shaded fuel break goals: 

  • Controlling fire behavior by reducing ladder fuels.
  • Opening the canopy.
  • Treating ground fuels.
  • Facilitate fire suppression (ground and air attack).

Examples of shaded fuel breaks in action:

  • Cone Fire — pictures of treated and untreated areas after the fire.
  • Stevens Fire at Cape Horn 2004 — pictures of flame length and the effect of fuel breaks.

The remains of mastication and chipping are left in place forming a mulch to protect the soil from compaction and erosion. Seedlings will sprout within one season, carpeting the ground and extending roots to retain the soil and feed on the composting material.

Maintenance of the shaded fuel break will be necessary every few years to keep the new vegetation from creating another fire hazard.

Invasive Species

Invasive Plant Information

One significant way that invasive plants can affect the areas they are invading is by changing fuel properties, which then affects fire behavior.  The most well-known effects of plant invasions on fire regimes involve those that increase the frequency, intensity, or length of the fire season.  Collectively, these changes increase what are commonly referred to as “fire hazards.” For example, annuals grasses that have invaded shrublands can increase the frequency of fire and the length of the fire season, and invaders that increase the woody fuel load can increase fire intensity. In addition, invading plants with high tissue flammability (i.e., Eucalyptus) can ignite easier and burn more intensely.

As fire regimes and other ecosystem properties become altered, restoration of pre-invasion conditions becomes increasingly more difficult and costly. As the invasive plant infestation spreads and alters the fire regime, the number of management actions and cost to restore native ecosystem functions increases, while the probability of success decreases. This is because restoration can ultimately require managing fuel conditions, fire regimes, native plant communities and other ecosystem properties, in addition to the invaders that caused the changes in the first place.  

As with other ecological impacts caused by plant invasions, the most cost effective way to prevent the establishment of an invasive plant / fire regime cycle is to take preventative steps early on in the process.

Fire Management and Invasive Plants

Fire management can help maintain natural habitats, increase forage for wildlife, reduce fuel loads that might otherwise lead to catastrophic wildfire, and maintain natural succession. Today, there is an emerging challenge that fire managers need to be aware of: invasive plants.  

Fire management activities can create ideal opportunities for invasions by nonnative plants, potentially undermining the benefits of fire management actions. This manual provides practical guidelines that fire
managers should consider with respect to invasive plants.

 pdfDownload the USFWS Handbook on Fire Management and Invasives.

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