Rebuilding After Wildfire

Since the 2015 Valley Fire in Lake County and the devastating 2017 Sonoma Complex Fires, we at A•SQUARED have witnessed firsthand the profound loss and resilience that wildfires leave behind.

We have walked sites with families returning to ashes. We have listened to their stories, their fears, and their hopes for starting over. Through this journey, we have committed ourselves to one purpose: helping homeowners rebuild smarter, stronger, and more fire-resilient homes for the future.

As architects experienced in wildfire recovery and resilient home design, we understand what it takes to rebuild in California’s High Fire Hazard Zones — including the most fire-prone regions of Southern California.

This article introduces key principles of fire-resistant design— blending passive and active protection strategies — to help homeowners make informed decisions after wildfire loss. It marks the beginning of a continuing series exploring critical strategies for designing homes in wildfire-prone landscapes.

Understanding the Risk: Fire Hazard Severity Zones

In California, the Department of Forestry and Fire Protection (CAL FIRE) and the Office of the State Fire Marshal (OSFM) map Fire Hazard Severity Zones (FHSZs) based on factors such as vegetation, topography, weather patterns, and historical wildfire behavior.
Areas are classified as Moderate, High, or Very High hazard zones.

If you are rebuilding within a designated FHSZ:

• You must comply with Chapter 7A of the California Building Code.
• Fire-resistant materials, defensible space planning, and specialized construction methods are required.
• Stricter standards may apply compared to areas of lower hazard.

However, meeting code minimums is only a starting point. True resilience demands a more thoughtful, layered approach—anticipating not just flame contact, but the embers, radiant heat, and flying debris that characterize wildfire behavior.

How Wildfires Destroy Homes

A wildfire's devastation often reaches homes not through towering flames, but through more subtle, insidious means:

• Wind-driven embers: Traveling miles ahead of the fire front, embers find weaknesses in a home’s exterior and ignite vulnerable materials.
• Radiant heat: The intense heat radiating from nearby burning structures or vegetation can ignite a home without direct flame contact.
• Direct flame exposure: Flames advancing through landscape or neighboring structures can reach and ignite homes.

Protecting your home means understanding, and actively designing against, each of these threats.

Designing for Fire Resilience: A Layered Strategy

At A•SQUARED, we design wildfire-resistant homes through a layered defense strategy — combining passive protections built into the structure and active defense systems that enhance performance during fire events.

Passive Resiliency: Built-in Protection

Passive strategies are the first line of defense. These elements are permanently integrated into the home's architecture and materials, offering protection without relying on power or human action.

Roofing Systems

• Class A fire-rated roofing (metal, tile, asphalt, or advanced composites) is essential.
• Metal flashing at roof-to-wall intersections blocks ember entry points.
• Metal gutters with debris guards prevent accumulation of flammable debris at roof edges.

Eaves and Vents

• Enclosed soffits shield the vulnerable underside of roof overhangs.
• 1/16" mesh vent screens prevent embers from accessing attic or crawl spaces.
• Unvented attic space provides a fully sealed and conditioned space which does not allow any entry points for embers.

Siding and Wall Assemblies

• Noncombustible siding materials such as fiber-cement, stucco, and metal offer superior ignition resistance.
• Fire-resistive sheathing (such as 5/8" Type-X gypsum or 1.5" mineral wool insulation) strengthens the structure against radiant heat exposure.
• Sealing all gaps larger than 1/8" is critical to prevent ember intrusion.

Special attention should be given to the first six vertical inches at the base of exterior walls, where ignition risk is highest.

Windows and Doors

• Dual-pane tempered glass windows dramatically improve resistance to heat and impact from embers.
• Metal-clad or fire-rated exterior doors reduce vulnerability to direct flame and radiant heat.
• Comprehensive weatherstripping at all entry points enhances ember protection.

Active Resiliency: Supplemental Defense Systems

While passive features provide continuous protection, active fire defense systems offer additional security during critical moments.

Exterior Fire Sprinkler Systems

• Roofline sprinkler systems wet roofing, soffits, and upper siding in advance of ember storms.
• Perimeter ground sprinklers moisten near-home landscaping and the base of exterior walls.
• Wind-resistant spray heads and backup power sources ensure system function during power outages or high-wind events.

It is important to note that exterior sprinklers are a complementary strategy.
They do not replace interior fire sprinkler systems, which are required by code for all new homes in California.

At A•SQUARED, we approach wildfire rebuilding with a depth of experience and a deep respect for what it means to rebuild after loss. Our services are designed to offer comprehensive support, including:

• Architectural design tailored to wildfire risk mitigation
• Site planning that balances defensibility with natural beauty
• Material selection focused on fire resilience and long-term performance
• Permit navigation and assistance with local wildfire rebuilding programs
• Conscious design rooted in resilience, sustainability, and human connection

Rebuilding after wildfire is not simply about replacing what was lost — it is about reimagining homes with greater resilience, care, and intention.

Through thoughtful design strategies — from passive protections built into the architecture to active defense systems that offer additional safeguards — we can create homes that are better prepared for the realities of California’s evolving wildfire landscape.

At A•SQUARED we view this process as a collaboration. We work closely with each client, listening carefully to your goals, your concerns, and your hopes for the future. Our team is continually researching emerging materials, technologies, and construction methods to build homes that are not only beautiful, but strong, adaptive, and enduring.

We believe rebuilding should be an opportunity: an opportunity to design spaces that are more deeply rooted in safety, sustainability, and spirit.