Wildfires have become a devastating and recurring challenge for Southern California residents, with the Los Angeles area experiencing some of the worst. Over the past decade, fires like the recent Palisades and Eaton Fires, the Woolsey Fire, Thomas Fire, Paradise Fire, and the Bobcat Fire have collectively destroyed thousands of structures, displacing families and business owners while underscoring the urgency of fire-resistant building practices. According to CalFire, in 2021 alone, wildfires burned over 2.5 million acres in California and destroyed over 3,600 structures. For those planning a remodel or addition, fortifying your home or business against fire risks is critical—not just for safety, but to meet insurance requirements and building codes.

While new construction offers opportunities to integrate fire-resistant materials and designs from the ground up, remodels and additions pose unique challenges. Retrofitting an existing building requires strategic modifications to maximize fire resistance. This article explores practical steps homeowners and business owners can take to enhance fire safety during renovations, with a focus on fortifying Type V construction—the most common construction type for single-family homes here in California.

For a deeper dive into fire-resistant construction, including the benefits of Type III construction, read our article on rebuilding after wildfires.

Understanding Type V Construction and Its Vulnerabilities

Type V construction is the most prevalent method used in residential homes and small commercial buildings. It typically consists of wood framing and combustible materials, making it particularly vulnerable to wildfires. Embers, which can travel miles ahead of the fire line, easily ignite wood siding, decks, and roofs. The radiant heat from nearby vegetation or structures can also cause ignition.

Despite its vulnerabilities, Type V structures can be retrofitted to better resist fire. Adding fire-resistant materials, upgrading landscaping, and improving defensible space are all practical steps to minimize risk during a remodel or addition.

Strategies for Fire-Resistant Remodeling

1. Roofing Upgrades

The roof is often the most vulnerable part of a building. To improve fire resistance:

  • Replace or overlay with Class A fire-rated roofing materials: Options include asphalt shingles, metal, clay tiles, or slate.
  • Seal gaps in roof edges and eaves: Use non-combustible flashing to prevent embers from entering. Enclose exposed wood on the underside of the eaves with stucco or cement fiberboard
  • Install a fire-resistant underlayment: This additional layer of protection can slow heat transfer and ember penetration.

CalFire emphasizes the importance of fire-resistant roofing in its Ready for Wildfire guide.

2. Siding and Exterior Walls

Wood or vinyl siding can ignite easily during a wildfire. Consider these upgrades during your remodel:

  • Replace combustible siding: Use non-combustible materials such as fiber-cement, stucco, brick, stone, or metal.
  • Add fire-resistant sheathing: Materials like gypsum board or fire-rated insulation provide additional protection.
  • Use heat-resistant paint or coatings: These can improve the fire resistance of existing siding.
  • Replace crawlspace vents: Many standard vents have openings that are large enough to allow embers to enter. Replace your vents with fire resistant models to stop embers from entering your home.
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3. Windows and Doors

Windows are a weak point during fires due to heat and flying debris. To mitigate risks:

  • Install dual-pane, tempered glass windows: These are less likely to break under heat exposure.
  • Replace your windows with a higher fire rated option: Replace old wood and aluminum windows with rated windows. Common fire ratings start at 30 minutes and go up from there. 
  • Use fire-rated door materials: Steel or solid wood doors offer better protection than hollow-core doors.
  • Seal gaps around windows and doors: Ensure embers cannot enter through cracks.
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4. Decks and Outdoor Spaces

Wooden decks and outdoor furniture can act as kindling in a wildfire. Consider these upgrades:

  • Replace wood decking with fire-resistant materials: Options include composite decking, concrete, or metal.
  • Install ember-resistant screens: Prevent embers from collecting under decks or in other vulnerable areas.
  • Keep decks and porches clear of flammable items: Remove firewood, furniture, and decorations during fire season.
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5. Defensible Space and Landscaping

Creating defensible space around your home is one of the most effective ways to prevent wildfire damage:

  • Follow the "100-foot rule": Maintain a clear area of 100 feet around your home, per CalFire guidelines.
  • Plant fire-resistant vegetation: Opt for succulents, lavender, or native plants with high moisture content.
  • Use hardscaping: Gravel, pavers, and stone paths can create effective firebreaks.

Learn more about defensible space requirements on the CalFire website.

Retrofitting the Interior for Fire Resistance

1. Fire-Rated Drywall and Insulation

Interior materials play a key role in slowing fire spread:

  • Upgrade to fire-rated drywall: Type X drywall provides extra fire resistance.
  • Install non-combustible insulation: Mineral wool and fiberglass are excellent options.
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2. Sprinkler Systems

Though more commonly associated with commercial buildings, residential fire sprinklers can save lives and property:

  • Install a sprinkler system: Modern systems are designed to integrate seamlessly into homes.
  • Maintain existing systems: Ensure sprinklers are inspected regularly for proper operation.
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3. Fire-Rated Doors and Interior Openings

Upgrading doors and openings can reduce fire spread:

  • Use fire-rated doors between garages and living areas: This is especially important in attached garages.
  • Install fire dampers in HVAC systems: These devices prevent fire from spreading through ductwork.
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Navigating Building Codes and Insurance Requirements

When planning a remodel or addition, it’s essential to comply with local building codes and insurance requirements. In California, the Wildland-Urban Interface (WUI) Code mandates fire-resistant materials and practices in high-risk areas.

  • Check local requirements: Contact your city or county building department to understand specific rules.
  • Consult your insurer: Many insurance companies offer incentives for fire-resistant upgrades. The California Insurance Commissioner’s website provides resources for understanding wildfire insurance coverage and discounts.

Visit the California Insurance Commissioner’s Wildfire Resources for more information.

Case Study: Fortifying an Existing Home

In this case study, we examine a family home in a fire-prone area of Los Angeles that underwent a comprehensive remodel to improve its fire resistance. Built in the 1980s with Type V construction, the home featured combustible materials, including a wood shake roof, wooden siding, and exposed eaves. The family prioritized fire-resistant upgrades during the renovation to protect their property and meet updated wildfire mitigation standards.

By following the principles of home hardening, outlined by CalFire, the family significantly reduced their fire risk. Below, we break down the improvements into categories that homeowners can use to self-assess and implement upgrades.

1. Roof: The First Line of Defense

The original wood shake roof was a significant fire hazard. Flying embers, a leading cause of structure ignition during wildfires, can ignite combustible roofing materials.

Upgrades Made:

  • Class A Fire-Rated Roofing: The family replaced the wood shake roof with Class A asphalt shingles, which offer superior fire resistance and are widely available.
  • Fire-Resistant Underlayment: Beneath the shingles, they added a fire-resistant underlayment to slow heat transfer and prevent embers from penetrating.
  • Sealed Roof Edges and Valleys: Non-combustible flashing was installed along roof edges, valleys, and around penetrations such as vents and chimneys to close gaps where embers might enter.

Key Takeaway for Self-Assessment:
Inspect your roof for its fire rating and condition. Replace combustible materials with Class A roofing and ensure all gaps are sealed.

2. Attic Vents and Eave Details

Unprotected vents and exposed eaves are among the most vulnerable parts of a home during a wildfire. Wind-driven embers can easily enter attics or soffits through openings, igniting the structure from within.

Upgrades Made:

  • Ember-Resistant Vents: The homeowners replaced standard attic and soffit vents with ember-resistant versions. These vents use fine mesh screens (1/8-inch or smaller) to block embers while allowing ventilation.
  • Boxed-In Eaves: The exposed eaves were enclosed using fiber-cement panels to create boxed-in eaves. This design not only eliminates gaps but also adds a layer of fire-resistant material to the home.
  • Soffit Vent Covers: Soffit vents were upgraded to meet wildfire-resistant standards, ensuring that airflow was maintained while preventing ember intrusion.

Key Takeaway for Self-Assessment:
Check for exposed eaves and unprotected vents. Replace vents with ember-resistant models and consider boxing in eaves to reduce vulnerabilities.

3. Siding and Exterior Walls

The home originally featured wood siding, which posed a significant risk. Wildfires can generate enough radiant heat to ignite wood siding, even without direct flame contact.

Upgrades Made:

  • Fiber-Cement Siding: The wood siding was replaced with fiber-cement panels, a non-combustible material that resists ignition from both embers and radiant heat.
  • Fire-Rated Sheathing: Beneath the siding, the family added gypsum sheathing, which provides an additional layer of fire resistance.
  • Seamless Sealing: All gaps and joints in the siding were sealed with non-combustible caulking to prevent ember intrusion.

Key Takeaway for Self-Assessment:
Assess your siding material. Replace wood or vinyl with fire-resistant alternatives like fiber-cement, stucco, or brick, and ensure all seams are sealed.

4. Windows and Doors

The original windows in the home were single-pane and the doors were made of hollow-core wood, both of which are highly susceptible to heat and embers.

Upgrades Made:

  • Dual-Pane Tempered Glass Windows: The family installed dual-pane windows with tempered glass, which is more resistant to breaking under heat exposure. This upgrade also improved energy efficiency.
  • Non-Combustible Frames: Window frames were replaced with metal to further enhance fire resistance.
  • Fire-Rated Doors: Hollow-core wooden doors were replaced with solid wood and steel doors, which provide better protection against heat and embers.

Key Takeaway for Self-Assessment:
Inspect windows and doors for fire resistance. Upgrade to dual-pane tempered glass and replace hollow-core doors with solid or fire-rated options.

5. Decks and Surrounding Areas

The family’s original wooden deck and outdoor furniture were vulnerable to ignition from falling embers.

Upgrades Made:

  • Composite Decking: The wooden deck was replaced with fire-resistant composite decking, designed to withstand radiant heat and ember exposure.
  • Ember-Resistant Screens: A metal screen was installed underneath the deck to prevent embers from accumulating in the area.
  • Clear Surroundings: All flammable items, including outdoor furniture, firewood, and decorations, were relocated away from the deck.

Key Takeaway for Self-Assessment:
Evaluate your deck and surrounding area. Replace wooden decking with fire-resistant 

6. Landscaping and Defensible Space

The property initially lacked sufficient defensible space, with flammable vegetation close to the house.

Upgrades Made:

  • Defensible Space Zones: The homeowners followed CalFire’s 100-foot defensible space guidelines, creating three clear zones:
    • 0-5 feet: All combustible materials were removed, and the area was replaced with gravel.
    • 5-30 feet: Shrubs and plants were spaced to prevent fire from spreading.
    • 30-100 feet: Trees were trimmed to create vertical and horizontal separation, reducing the risk of crown fires.
  • Fire-Resistant Vegetation: Flammable plants like juniper and pine were replaced with fire-resistant species, including succulents and lavender.

Key Takeaway for Self-Assessment:
Examine your property for defensible space. Remove flammable vegetation and replace it with fire-resistant plants while maintaining appropriate clearance.

7. Garage and Attached Structures

Garages and attached structures often contain combustible materials that can ignite easily during a wildfire.

Upgrades Made:

  • Fire-Rated Door: The door between the garage and the living space was upgraded to a fire-rated model.
  • Garage Vent Covers: Ember-resistant vent covers were installed to prevent ember intrusion.
  • Clear Storage: Flammable materials were relocated to an outdoor storage shed located away from the home.

Key Takeaway for Self-Assessment:
Inspect your garage and attached structures. Install fire-rated doors, protect vents, and move flammable materials away from the home.

8. Sprinkler System and Fire Suppression

Although the home did not originally have a sprinkler system, the family opted to install one as an additional safeguard.

Upgrades Made:

  • Residential Sprinkler System: A discreet, modern system was added to protect interior spaces.
  • Fire Suppression Equipment: The family also installed fire extinguishers and hose reels in accessible locations around the property.

Key Takeaway for Self-Assessment:
Consider installing a sprinkler system or maintaining portable fire suppression tools like extinguishers and hoses.

Building a Fire-Resistant Addition: Design Principles for Safety

When planning an addition to your home in a fire-prone area, integrating fire-resistant materials and construction techniques is crucial. Whether you’re expanding your living space with a single-story addition or building upwards with a second-story addition, thoughtful design choices can significantly reduce your fire risk while meeting modern building codes and insurance requirements.

For a single-story addition, Type III construction provides an excellent solution for enhanced fire resistance. Type III construction uses non-combustible materials like masonry or concrete for exterior walls while incorporating wood for interior components. A slab-on-grade foundation eliminates the risk of embers accumulating beneath the structure, a common vulnerability with raised floors. Additionally, a 2-hour fire-rated roof assembly can provide critical protection, slowing heat and flame penetration and giving firefighters valuable time to respond in the event of a wildfire. These design elements ensure your new addition is built to withstand even severe fire exposure.

For a second-story addition, the challenges and opportunities are different. The second story must seamlessly integrate with the existing home while adhering to fire-hardening principles. This includes using fire-resistant materials for the new exterior walls, roofing, and windows. As we noted above, dual-pane tempered glass windows, fiber-cement siding, and a Class A fire-rated roof are essential. A second-story addition also presents an opportunity to fortify the entire home. While upgrading the upper floor, you should extend fire-resistant materials and retrofits to the first floor, ensuring the entire structure meets modern standards.

When undertaking a remodel or addition, adding a fire sprinkler system to your entire home is a highly effective way to enhance fire safety. Residential sprinklers are designed to activate quickly in the event of a fire, controlling or even extinguishing flames before they can spread. For single-story or second-story additions, integrating sprinklers into the new construction and extending the system throughout the existing home can provide comprehensive protection. Modern residential sprinkler systems are discreet, with flush-mounted heads that blend seamlessly into ceilings and walls, preserving your home’s aesthetic while offering peace of mind. Additionally, installing sprinklers often qualifies homeowners for significant insurance discounts, making it a wise investment for safety and financial savings. A whole-home sprinkler system is an invaluable layer of defense, especially in fire-prone areas.

Whether single-story or multi-story, it’s critical to involve professionals, like Letter Four, who are experienced in fire-resistant construction to ensure the design adheres to both local codes and best practices. With proper planning, your addition will not only expand your living space but also contribute to your home’s resilience against the growing threat of wildfires.

Summary of Results

After completing these upgrades, your family’s home will be significantly better prepared to withstand wildfire exposure. These changes not only enhance the property’s safety but also help you qualify for an insurance discount under wildfire mitigation programs.

By using this case study as a guide, homeowners can conduct their own self-assessment and identify areas where improvements are needed. For more detailed advice, consult CalFire’s comprehensive Home Hardening guidelines.

Conclusion

In fire-prone regions like Los Angeles, fortifying your home or business during a remodel or addition is a critical investment in safety and resilience. While Type V construction poses inherent risks, strategic upgrades to roofing, siding, windows, and landscaping can significantly reduce vulnerability. By following state and local guidelines, you can protect your property and ensure compliance with modern fire codes.

For more information on fire-resistant construction and rebuilding after wildfires, explore Letter Four’s article on Type III construction. 

Ready to Protect Your Home from Fire Threats?

Wildfires are an ever-present danger, but with the right steps, you can fortify your home and safeguard your family. For more resources on fire-resistant construction, remodeling tips, and actionable advice, visit our Fire Rebuild Resources Page.

If you’re ready to take the next step or want personalized guidance on hardening your home against fire threats, book a call with our team today. Together, we can create a safer, more resilient home that’s built to withstand the challenges of living in fire-prone areas. Don’t wait—start your journey to peace of mind now!

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