Updated: July 10, 2024

Purgula would like to express special thanks to Steve Hawks for his expert guidance on this article.

As part of the 2024 Pacific Coast Builders Conference (PCBC), the Insurance Institute for Business & Home Safety (IBHS) and its partners held a dramatic burn demonstration to illustrate how Wildfire Prepared Homes can survive a conflagration.

The message was simple: with certain mitigation measures in place, your home can become resilient to wildfire threats and risks.

By implementing current wildfire resiliency practices, homeowners can dramatically increase the likelihood of preventing total losses of their homes due to wildfire.

IBHS and its partners complemented the fire demonstration with additional educational sessions for industry professionals with the goal of sharing current best-practices for building and retrofitting homes with the goal of fire resistance.

In parallel to educating members of the construction industry, IBHS and its partners have also begun spreading awareness of wildfire resilience to homeowners to help them learn how to safeguard their homes, especially against ember attacks during annual wildfires.

This public-outreach effort extends to their newly launched Wildfire Prepared Home certification program, an important initiative to encourage homeowners to take a proactive, on-going approach towards mitigating wildfire risks.

To support these worthy safety initiatives, we have summarized our learnings to allow homeowners to gain a quick handle on what they need to know and how to take action.

Table of Contents

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The 2024 PCBC IBHS Wildfire Demonstration

In conjunction with its host of partners, including the California Building Industry Association (CBIA), California Homebuilding Foundation, Donald Chaiken Building Industry Technology Academy (BITA), and Anaheim Fire & Rescue, IBHS conducted a demonstration of Wildfire Preparedness for attendees of the 2024 PCBC tradeshow held June 19 in Anaheim, California. The event was narrated by Steve Hawks, Senior Director for Wildfire at IBHS, and Denny O’Neil, Assistant Chief of the CAL FIRE Home Hardening program.

IBHS PCBC 2024 Fire Demonstration: Unmitigated structure burning

Scene from the 2024 PCBC IBHS Fire Demonstration

The purpose of the demonstration was to illustrate the importance of proper construction materials and defensible spacing between residential structures and surroundings, to mitigate damage during annual wildfires.

BITA High School construction students PCBC 2024 Fire Demonstration in Anaheim with IBHS

BITA High School Students who built the two structures used in the 2024 PCBC IBHS Fire Demonstration in Anaheim, California

Side-by-side structures, with starkly different levels of wildfire mitigation, were built by high school students in the BITA 4-year construction education program, specifically for the demonstration.

PCBC 2024 IBHS Fire Demonstration in Anaheim - mitigated and unmitigated structures with descriptions

PCBC 2024 IBHS Fire Demonstration: Traits of the Mitigated Structure vs. the Unmitigated Structure

For Structure 1 (unmitigated), on the left, the roof was the sole component that was mitigated for wildfire — a Class-A fire-rated composition shingle roof. The remaining components were constructed using materials typically found in residential structures during the last few decades, before current California building codes, such as: combustible wood siding; non-compliant, non-tempered windows; non-compliant vinyl gutters; uncovered gutters with leaves; and open eave.

Structure 2 (mitigated), on the right, was built using current wildfire mitigation materials and methods: Class-A fire-rated roof; noncombustible siding; noncombustible covered gutters without debris; upgraded windows with two panes of tempered glass; enclosed eave; and noncombustible landscaping with 5 feet of structure.

IBHS Fire Demonstration at PCBC 2024 in Anaheim

After intentional ignition of surrounding landscaping mulch, Structure 1 began to smolder and proceeded to ignite into visible flames all the way up to the home’s foundation.

In less than one hour, the entire structure was consumed in flames with billowing black smoke hurling toward onlookers.

2024 PCBC IBHS Fire Demonstration mid-burn

The 2024 PCBC IBHS Fire Demonstration: A Tale of Two Structures

Simultaneously, the mulch in front of Structure 2 was ignited, but the fire failed to progress closer than 5 feet from the structure. Thus, Structure 2 — with noncombustible landscaping, together with the noncombustible building materials — resulted in a completely benign fire event.

IBHS Fire Demonstration at PCBC 2024 in Anaheim: Part 2

At the end of the demonstration, only one structure remained, virtually unscathed by the same fire that completely consumed the other, along with its surrounding landscaping.

Aftermath of IBHS Fire Demo at PCBC 2024: Unmitigated Structure vs. Mitigated Structure

If ever offered the opportunity to witness a similarly controlled fire demonstration, we strongly recommend doing so.

Five important reasons to attend a fire demonstration are to:

  1. Feel the intense heat
  2. Experience the shifting smoke
  3. Observe how fast fire finds fuel and spreads
  4. See how quickly a fire can lead to the total loss of a home in real-time
  5. Witness the effectiveness of how mitigation steps can meaningfully reduce fire damage

Despite standing at a safe distance, we were surprised by how powerful the radiant heat felt — a truly unforgettable experience!

IBHS PCBC 2024 Fire Demonstration Aftermath

Aftermath of the 2024 PCBC IBHS Fire Demonstration

The demonstration also reminded attendees how weather conditions play a critical factor in any wildfire.

During the demo, the conditions were actually mild in terms of the weather (e.g. high humidity, low winds, and moderate temperatures), and in terms of conditions of the two structures (e.g. new materials surrounded by fresh landscaping).

In real-life situations, existing homes will more likely have older, drier construction materials and be surrounded by dry, more overgrown landscaping, which would cause structures to ignite more quickly.

 

Wildfire Literacy & Preparedness

Here’s a collection of lessons-learned and statistics related to wildfire preparedness to provide a helpful base of understanding before exploring more intricate details pertaining to wildfire resiliency.

Raging wildfire with flying embers approaching trees at night

A raging wildfire with flying embers approaching trees at night

Key Points About Wildfires from IBHS

  • In a wildfire disaster, homes can be ignited by embers, flames and radiant heat
  • Wind is the single, most significant variable that causes extreme wildfire behavior and the loss of structures
  • 90% of structural ignitions from wildfires are caused by wind-blown embers, directly or indirectly
  • Floating embers pose the greatest threat, as high winds can carry them well ahead of a fire front, igniting spot fires in and around residential areas.
  • Small, airborne embers can easily enter homes that lack proper protection
  • Firefighters’ first priority is life safety and they can lose a lot of time tending to evacuations before being able to defend structures
  • IBHS’ approach to fire resiliency is to help homeowners reduce property losses and prevent avoidable damage, by applying multiple layers of defensive tactics
  • 85% of all wildfires in the United States are caused by humans (Source: US Forest Service)
  • There are only two natural causes of wildfires: lightning strikes and spontaneous combustion
  • 4.8 million U.S. homes were identified at high or extreme risk of wildfire, with more than 2 million in California alone
  • Outside of California and Utah, there are no enforced, statewide codes addressing wildfire exposures to residential and commercial property
  • The separation of wildfire safety elements from traditional building codes and the absence of clear guidance on how such elements can be integrated into building codes has resulted in limited use by state and local officials.
  • There is a greater than a 90% chance that a home will be a total loss, if it is ignited by a wildfire.
  • Each burning home with a non-fire-rated wood shake roof contributed to the ignition of 10 other homes. (Bryner, 2000)
  • Ignition of combustible siding can result in rapid fire growth (Green et al. 2022)

 

Key Wildfire Risks to Understand

For the perspective of individual homeowners, the risks of wildfire can be grouped into three categories which correlate to surrounding threats of wildfire:

 

Environmental Wildfire Risks

The wildfire behavior triangle determines how severe and intense a wildfire can become, which is made up of:

  • Weather (wind, temperature, and relative humidity)
  • Fuel (anything that can burn, such as vegetation, fences, buildings, structures, etc.)
  • Topography (steep slopes and other features)
Wildfire behavior triangle: Weather, Fuel, Topography

Wildfire Behavior Triangle: Weather, Fuel, Topography
Image courtesy of IBHS

The wind, temperature, and relative humidity are the three biggest factors under the weather component, with wind being the single biggest factor.

An example scenario of high environmental risk would be dry vegetation after an extended period of hot temperatures, low humidity, and little rain, combined with hot, gusting winds, during the months of September and October. During periods of high environmental fire risk, it’s imperative to take extra precautions and be highly vigilant.

National Park Service Fire Danger sign with High Danger, Grand Teton National Park

Image courtesy of the US National Park Service

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Residential Neighborhood Wildfire Risks

Southern California housing community spared from wildfire

A Southern California housing community spared from wildfire

The following wildfire risks pertain to the vulnerability of communities:

  • Proximity to wildfire-prone areas
  • Poorly maintained common areas with overgrown, dry vegetation and trees
  • Connected fuel sources (e.g. attached households; connected wooden fences)
  • Minimal barriers (e.g. no retaining walls or perimeter firescaping)
  • Ignitable structures (e.g. homes; decks; sheds; wood piles; club houses; and vehicles)
  • Concurrent ignitions (e.g. spot fires spread by floating embers)
  • Congested roadways that inhibit emergency response vehicles entering and residents fleeing
  • Not sharing emergency plans and contact lists to facilitate wellness checks and evacuations
  • Not having community fuel modification plans or zones
  • High density housing

 

Individual Home Wildfire Risks

Fire Safe Marin Defensible Space Around Mansion Paradise Fire

Defensible space does its job around an isolated mansion in the 2018 Camp Fire, Paradise, California
Image courtesy of Fire Safe Marin

The following items are well-known risks that have caused homes to ignite and/or have contributed to the severity of residential fires:

  • Not having a Class A roof that is clear of debris
  • Unprotected eaves, vents and rain gutters
  • Wooden fences connected to homes
  • Vegetation within five feet of the home
  • Storing combustible items underneath an unprotected deck
  • Dead, dry, and overgrown landscaping and vegetation
  • Tree branches close to the home
  • Large trees with canopies that touch
  • No natural defenses (e.g. rocks, cement, retaining walls, hardscaping, firescaping, etc.)
  • Combustible materials and supplies close to the home (e.g. paint, refinishing supplies)
  • Parallel, back-to-back fences between neighboring lots that are less than 5 feet apart
  • Exposed spaces underneath bay windows
  • Homes without at least 6 vertical inches of noncombustible siding at the base of exterior walls
  • Properties not displaying an address number that is clearly visible from the road for emergency response personnel
  • Homes without cleared driveways and walkways for firefighters to reach your home quickly
  • Properties not prepared for their specific type of terrain, such as atop a steep hillside where fire travels fastest uphill by preheating dried vegetation from below

 

The Two Fronts of Making Your Home Wildfire Prepared

There are many actions a homeowner can take to make their home more resilient against wildfires. Given the breadth of choices, it’s helpful to conceptualize options belonging within one of two key concepts:

  1. Home Hardening
  2. Defensible Space

Activities within each of these two areas of wildfire resilience will then make your home safer by providing one of two benefits:

  • Reducing Exposure
  • Increasing Resilience
IBHS Wildfire Prepared Home: Reduce Exposure & Increase Resilience illustration

Ways to Reduce Exposure and Increase Resilience
Image courtesy of IBHS

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Home Hardening

Home hardening primarily pertains to building materials and components that can help resist the intrusion of flames and embers projected by a wildfire. Home hardening can be done during new construction or by retrofitting an older home.

Large home with Class-A fire resistant metal roof

Home hardening incorporates fire-resistant building materials in addition to mechanisms that will prevent ignition or the spreading of a fire. Specifics on how you can hardened your home are included in the section that explains the IBHS Wildfire Prepared Home certification program.

Home with stone pavers, metal roofing and fire-resistant garage doors

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Defensible Space

As the name implies, Defensible Space involves creating protective buffer zones between your property and an encroaching wildfire from surrounding natural terrain. The purpose of a defensible space is to slow or stop the spread of wildfire and to protect your home from embers, flames and heat.

Firescaping fire-resistant landscaping with short grass, borders, rocks and gravel

The following interrelated and overlapping practices are vital for creating an effective defensible space:

All of these techniques can help reduce the chances of ignition, lower fire intensity, and hinder how quickly a fire spreads. They also involve creating different areas of protection within several concentric zones differentiated by the distance of each zone to your home. The most important zone is 0 to 5 feet around the exterior walls of your home, which is commonly referred to as the Home Ignition Zone, or Zone 0.

 

Fuel Modification

Fuel Modification is the process of reducing the threat of wildfire, by removing, limiting or obstructing “fuel sources” and “fuel pathways”, which enable fires to spread and grow in intensity. Fuel modification also pertains to mitigating nearby combustible threats — both natural and man-made — such as vegetation, wood piles, and storage sheds with hazardous supplies.

When conceptualizing “fuel modification”, the goal is to create obstacles that will curtail a fire from easily finding “connected” fuel sources that can eventually spread directly towards your home.

Besides implementing ground-level barriers, it’s also important to incorporate two types of vertical barriers:

  • Increasing the distance of lower tree branches from the ground
  • Trimming tree canopies to create aerial buffers between other tree canopies

 

Vegetation Management

Vegetation management is a key part of fuel reduction, and typically involves the following on-going tasks:

  • Removing leaves, dead branches and brush
  • Keeping grass neatly cut and sufficiently watered
  • Pruning bushes and trees to prevent overgrowth
  • Cutting overhanging tree branches close to your home
  • Trimming tree canopies so that they do not touch other trees and structures
  • Removing low branches that are within six feet of the ground on mature trees
  • Keeping trees, bushes and plants sufficiently spaced apart to prevent cascading ignition

 

Firescaping

Firescaping, also known as fire-smart landscaping, combines landscaping and hardscaping techniques centered on the planting of “fire-safe” or “fire-resistant” plants, shrubs and trees. Done well, firescaping will decrease the likelihood of ignition, reduce fuel sources, and make vegetation management easier, while enhancing the overall beauty of your property.

Not only are the types of plants selected important, but plant spacing, location, and maintenance (e.g. pruning, watering, removing dead material, etc.) are all equally important for sustaining an effective firescaped property.

NOTE: Some wildfire resiliency experts prefer not to use the term “fire-resistant plants” due to inconsistent testing, confusing definitions, and other matters, such as the importance of proper placement and care. All of these issues can lead to misleading labels and flawed expectations. A key concept to understand is that all plants can and will burn in a wildfire under the right conditions, no matter if they were labeled “fire-resistant”. Understanding the variables that make certains plants less flammable than others —  moisture content, ability to shed dead vegetation, shape, care needs, etc. — is critical for maintaining a “natural” defensible space

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Certifying Your Home for Wildfire Resiliency with IBHS

IBHS Wildfire Prepared Home Certification Program logo

Image courtesy of IBHS

Although California has some of the most stringent fire codes for homes in the world, homeowners should still consider retrofitting their existing structures for sound wildfire preparedness.

IBHS offers two wildfire preparedness designation levels, depending on the type of home you seek to certify:

Criteria for Wildfire Prepared Base & Plus Certification Programs by IBHS

Criteria for Wildfire Prepared Base & Plus Certification Programs by IBHS
Image courtesy of IBHS

Since the program is a homeowner-driven process, success is contingent upon the property owner following the guidelines in order to achieve the Wildfire Prepared Home designation. Currently, the two certificate programs are only available for California-based dwellings that are single family detached homes with 3-stories or less, and that have a 5-foot noncombustible buffer around the perimeter of the home.

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Wildfire Prepared Home Base Certificate

Wildfire Prepared Home Base is the certification for existing homes, which involves retrofitting vulnerable areas around the property. Specifically, the certification process is concerned with three key areas of the home that are the leading cause of vulnerabilities during a wildfire:

  • Roof
  • Building Features (Vents, Soffits and Eaves)
  • Defensible Space (Landscaping, Vegetation and Outbuildings)
Wildfire Prepared Base Certificate Criteria by IBHS

Criteria of the Wildfire Prepared Home Base certificate by IBHS
Image courtesy of IBHS

Criteria for the IBHS Wildfire Prepared Home Base Designation

Roof

  • Ensure roof is Class A fire-rated
  • Install noncombustible gutters and downspouts
  • Keep roofs, gutters, and downspouts of clear of debris

Building Features:

  • Install ember- and flame-resistant vents
  • Ensure a 6-inch vertical noncombustible clearance at base of exterior walls

Defensible Space

  • Create and maintain the home ignition buffer zone (0-5ft), including removing any overhanging branches
  • Clear and maintain decks, underdeck areas and covered porches
  • Remove combustible fencing within 5 feet of the home
  • Keep accessory structures compliant
  • Maintain your defensible space

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Wildfire Prepared Home Plus Certificate

New residential construction and homes which have undergone exterior home renovations are candidates for Wildfire Prepared Home Plus certification. The expectation to attain this level of certification is that the homeowner will meet the requirements of the Home Base level in addition to numerous other stringent requirements.

This designation requires mitigations that are commonly part of the home’s facade, such as noncombustible siding, upgraded windows and other requirements which protect against flames and radiant heat.

Criteria for the IBHS Wildfire Prepared Home Base Plus Designation

Meet the Wildfire Prepared Home Base criteria, plus the following:

  • No structures within 30 feet of home
  • Cover gutters
  • Enclose underside of eaves
  • Install metal dryer vent
  • Install a noncombustible exterior wall cover
  • Ensure shutters, if in place, are noncombustible
  • Upgrade windows to two panes of tempered glass
  • Upgrade doors utilizing noncombustible or ignition-resistant materials
  • Enclose the space underneath bay windows
  • Upgrade to a noncombustible deck
  • Remove back-to-back fencing
Wildfire Prepared Plus Certification Program and Criteria by IBHS

Additional criteria required to earn the Wildfire Prepared Home Plus designation by IBHS
Image courtesy of IBHS

 

How to Prepare Your Home for the Certification Process

If interested in pursuing a certificate, be sure to confirm first that your home meets the following initial criteria:

  • Your home is in California
  • Your home is a single-family detached home with no more than 3 stories
  • Your home has a 5-foot noncombustible buffer around its perimeter
IBHS Home Ignition Zone Illustration: 0 to 5 feet buffer around the perimeter of a home

Illustration of the Home Ignition Zone (AKA Zone 0), a 5 feet buffer around the perimeter of a home
Image courtesy of IBHS

All of the details on the certification criteria can be found in the IBHS guide “How to Prepare My Home Checklist”, including how to create the 0 to 5 feet noncombustible zone around your house.

Initial Certification Process

  • Explore the “How to Prepare My Home Checklist”
  • Take the free Online Home Assessment
  • Conduct DIY work to meet the criteria of the corresponding certificate
  • Apply, including paying a non-refundable application fee
  • Schedule and host an on-site inspection
  • Receive your IBHS designation
  • If not meeting certification criteria, complete necessary work and submit photos within 90 days for re-evaluation

Recurring Certification Process

  • Conduct annual landscape review
  • Receive re-designation

 

Wildfire Resiliency Resources

 

About IBHS

The Institute for Business & Home Safety (IBHS) is a nonprofit organization that researches methods of improving and strengthening living structures against severe weather and wildfires. Its research center is located on 90 acres in Chester County, South Carolina (approximately 45 minutes south of Charlotte, North Carolina).

Established in 1977 by the property-casualty insurance industry, IBHS began focusing on natural hazards in the 1980s as new problems and natural disasters became prevalent throughout the nation.

 

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