Building in the Wildland

Communities located in wildfire-prone areas need to take extra measures to live safely. There are many ways to prepare communities and properties for wildfire that include creating and maintaining adequate defensible space and hardening structures. Using building construction methods that are rated for the wildland it can help reduce the likelihood of building ignition. Protecting your structure by selecting, locating, and maintaining vegetation and other combustible materials on your property can reduce the chance of a wildfire ignition.

How Structures Ignite

Structures ignite during a wildfire because of one or more of these three wildfire exposures:

  • EMBERS - Remember the ember! 60 to 90 percent of home ignitions occur because of embers.
  • DIRECT FLAMES - The source can be from the wildfire itself or from combustibles near your structure.
  • RADIANT HEAT - Structures do not need direct flame contact to ignite. If the radiant heat is high enough, nearby ignition to your structure can occur.

Defensible Space

Defensible space is the buffer between your structure and the surrounding area. Adequate defensible space acts as a barrier to slow or halt the progress of fire that could overwhelm your structure.

Discover practical ways to protect your property from wildfire. 

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Structures ignite during a wildfire because of one or more of these three wildfire exposures:

1. Embers are the most common cause of home ignition. They are small pieces of burning material that are light enough to be blown through the air. They can create spot fires when they land on combustible materials, such as accumulated gutter debris and can enter the home through small openings or vents. It is estimated that between 60 to 90 percent of home ignitions occur because of embers.

2. Direct flame contact refers to flames touching a structure or other combustible materials. It may come either from the main wildfire or from combustible materials near your home. Features like fences and attached decks made from combustible materials often hasten the spread.

3. Radiant heat generated from burning structures or vegetative material can ignite a home without direct flame contact. If the fire is close enough to a combustible material, or the radiant heat is high enough, a home ignition can occur. Radiant heat is particularly challenging in densely populated areas, where the heat from one burning home can ignite the next. 

IBHS Ember Storm Video

Information coming soon. 

New Construction CBC Chapter 7A Materials and Construction Methods for Exterior Wildfire Exposure

What is the purpose?

Building materials, systems and/or assemblies used in the exterior design and construction of new buildings.

It established minimum standards for the protection of life and property by increasing the ability of a building to resist the intrusion of flames or burning embers.

Where does it apply?

New buildings built after July 1, 2008, located in any Fire Hazard Severity Zone or any Wildland-Urban Interface Fire Area. This includes residential, commercial, educational, and other building types.

What building standards does it apply to?

Minimum building standards were established for the protection of life and property to resist the intrusion of flames or burning embers. Each section outlines the codes requirements for new construction in the FHSZ or Wildland Interface.

CBC Chapter 7A Materials and Construction Methods for Exterior Wildfire Exposure

Section 701A.3.1 Application Date and Where Required
Section 701A Vegetation Management
Section 705A Roofing
Section 706A Vents
Section 707A Exterior Coverings
Section 708A Exterior Windows, Skylights, and Doors
Section 709A Decking
Section 710A Accessory Buildings and Miscellaneous Structures

Other Considerations

Local jurisdictions can amend the California Building Code, so always consult your local building official and hire a licensed contractor who understands Chapter 7A. Consider Chapter 7A complaint products when you are replacing an exterior building component.

Helpful Resources

STATE FIRE MARSHAL WUI PRODUCTS HANDBOOK
OSFM BUILDING MATERIALS LISTING

What is the California Wildfire Mitigation Program?

To strengthen community-wide resilience against wildfires, the California Governor’s Office of Emergency Services (CAL OES) has partnered with CAL FIRE to develop a state home hardening initiative to retrofit, harden, and create defensible space for homes at high risk to wildfires, focusing on high socially-vulnerable communities and providing financial assistance for low– and moderate income households. 

Visit the CAL OES CWMP page for programmatic information and how to apply
OSFM CWMP Board Meeting Information webpage

What is Hazard Mitigation Methodology?

The National Institute of Standards and Technology (NIST), CAL FIRE, and the Insurance Institute for Business and Home Safety (IBHS) collaborated developing the HMM to use the latest laboratory research findings and knowledge from post-fire field observations to effectively harden structures.

The proposed method has two goals:

1. Protect homes and property to reduce loss,

2. Prioritize cost-effective protection.

Learn more about HMM and hardening actions with construction guidance below.

Hazard Mitigation Methodology Website

Resources will be available in 2024.

Course Goals:

  • Provide local building officials, builders, and fire service personnel online training on how to access, interpret, and comply with the California Building Code Chapter 7A Materials and Construction Methods for Exterior Wildfire Exposure.
  • Provide local building officials, builders, and fire service personnel online training on how to access and utilize the CAL FIRE Office of the State Fire Marshal's (SFM) Building Materials Listing Program (BML), Building Materials Listing Search Tool and State Fire Marshal Listed Wildland Urban Interface (WUI) Products Handbook.
  • Provide a building officials, builders, and fire service personnel documentation for completion of the online training.