Fire-Resistive Architecture And Construction In The Aftermath Of The Los Angeles Fires
The Palisades Fire, seen from Tarzana on January 10th, 2025 as it approached Mulholland Drive
The devastation caused by the recent wildfires in Los Angeles serves as a stark reminder of the urgent need for fire-resistive construction. Entire communities have faced displacement, homes have been lost, and the resilience of our built environment has been put to the test. As these disasters become more frequent and intense, will public legislators, architects, builders, and homeowners rethink how we design and construct homes to better withstand fire threats?
For many homeowners, Type V wood-frame construction remains the standard in Southern California due to its cost-effectiveness and flexibility. However, in light of the carnage of the Eaton and Palisades fires and those that preceded them should we not question the adequacy of the existing fire hardening measures mandated in fire hazard zones by the California Building Code? Is it inevitable that the understandable urgency to rebuild will leave no space for a radical change in the way we address wildfire resistance in residential building design and construction method? While a reminder of fire resistance methods is timely, it would be unfortunate if, yet again, significant progress was not made in advancing other materials in substitution for the traditional wood frame—both those mundane and costly, such as concrete and concrete masonry units (CMU) and those considered perhaps eccentric, such as adobe, and rammed earth.
Pacific Coast Highway closed during the Palisades Fire in January 2025
Improving Fire Resistance in Wood-Frame Construction
Wood-frame homes are particularly vulnerable to fire, but several methods can significantly enhance their resilience. According to Sam Williams of Los Angeles based Consolidated Architects “There are many steps that can be taken to improve the fire resistance of homes, but it makes sense to start with those that are readily achievable without undue expense or unusual construction methods. These steps can create a surrounding landscape that addresses fire concerns and eliminate an easy path for fire to spread to the house”.
An emphasis on both active and passive systems to optimize fire protection should be considered as you select the design and construction team for your new home project, including the architectural and engineering roles, prime contractor and sub-contracted trades. Look not only for an emphasis on fire retardant materials (passive design) and active fire suppression systems (both interior and exterior) but also a defensible design that addresses fire risk in overall site layout and design detail. Prefabricated modular systems can also incorporate active and passive fire resiliency elements which should be verified with the manufacturer, project architect and general contractor responsible for site work.
1. Fire-Rated Sheathing and Siding
Using fire-rated exterior gypsum sheathing, cement board, or fiber-cement siding in substitution for wood risks little change to the exterior appearance but can help protect a home from ignition and slow the spread of flames.
2. Insulation
Fire-resistant insulation such as mineral wool, fire-resistant fiberglass or fire-retardant-treated rigid foam board, instead of traditional insulation materials, such as fiberglass batts with paper backing, spray foam and cellulose, can improve fire safety.
3. Non-Combustible Roofing Materials
Clay or concrete tiles, metal roofing, and fire-resistant asphalt shingles reduce the risk of embers igniting a home.
4. Defensible Space and Landscaping
Creating a buffer zone with fire-resistant vegetation and non-flammable materials helps minimize the chances of fire reaching a structure. Consolidated Architects suggests removing plants known to be fire hazards, such as eucalyptus trees, removing hedges and other easily flammable plants adjacent to the house and working with a qualified landscape architect to help specify plants for particular climate zones that minimize fire danger.
5. Vented Attics
Open vents to attic spaces can provide access for embers to reach flammable materials such as exposed wood framing and insulation. Designing a home to eliminate these spaces can further reduce the risk of ignition. Where attic spaces occur, vents that close off airflow in the presence of high heat are recommended or, if they are not appropriate, then fire screening must be installed behind all vents.
6. Exterior sprinkler systems: encompassing the exterior of the home and its roof with a water barrier can increase its fire resilience.
7. Easy paths for fire spread: removing unprotected wood from the exterior of the house and ensuring eaves do not have exposed wood decking or any small rafter tails. Metal doors and dual paned windows with fire resistant glass can also provide additional protection.
8. Fireproofing wood and steel: SFRM (Sprayed Fire-Resistive Material) is applied typically to structural steel components most commonly in commercial structures. It is visible in particular in public parking facilities on the exposed steel beams and columns. Exposed wood details can be treated with a fire retardant intumescent coating which swells when exposed to heat, but this is only a supplemental measure that slows down ignition and does not render the wood non-combustible.
Green shoots in the charred landscape of the Santa Monica Mountains looking South from the Mulholland Drive dirt road.
alternative fire-resistant structural systems
For homeowners looking beyond traditional wood-frame construction, several alternatives offer enhanced fire resistance:
Concrete Construction
Concrete is naturally fire-resistant and can withstand extreme temperatures without compromising structural integrity. Reinforced concrete homes, especially those built with insulated concrete forms (ICFs), offer both fire resistance and energy efficiency.
Concrete Masonry Units (CMU)
CMU construction provides excellent fire separation and does not burn, making it potentially appropriate for homes in fire-prone areas. When paired with fire-resistant mortars and finishes, CMU structures achieve superior fire ratings while requiring minimal maintenance.
Adobe and Rammed Earth Construction
Adobe had been used in Southern California for centuries, and for good reason—it’s naturally fire-resistant with natural insulation qualities, but the method has been largely ignored as a construction method since the mid 19th century. Rammed earth construction, which compacts layers of soil into solid walls, also offers high fire resistance. Like adobe, its density makes it difficult for fire to penetrate, while its thermal mass helps regulate indoor temperatures.
Research has demonstrated the impressive fire hardiness of abode and other earthen construction methods (thick adobe walls absorb heat slowly, making it difficult for fires to spread), provided other features are not included that could otherwise aid ignition such as exposed beams and open vents. Modern engineering techniques and the use of other materials to provide reinforcing qualities can also strengthen these structures, including by adding cementitious and other stone based binders that balance safety, durability, and sustainability. There is a challenge to overcome the perception of these methods by some as archaic and unsuitable for modern applications. However, this is changing with increased international research demonstrating its benefits, the outreach of non-profits, such as New Mexico based Adobe in Action, the emergence of tech driven solutions for compressed earth block construction and suppliers, and, since 2022 the biennial International Conference on Earthen Construction bringing together researchers, academics and engineers. The next conference will take place in Lisbon at the Universade Nova de Liboa in July 2026.
3D Printing and the Future of Fire-Resistant Construction
One of the most exciting advancements in fire-resistant architecture is 3D-printed construction using earth-based materials. This technology allows for the rapid and precise layering of non-combustible materials such as clay, sand, and fiber-reinforced adobe. These structures offer a modern, sustainable alternative to traditional wood-frame homes, reducing waste and improving fire resilience. In fire-prone regions like Los Angeles, 3D-printed adobe homes could redefine how we approach homebuilding.
A Call to Action: Building for the Future
Integrating fire-resistant construction is essential. For homeowners who prefer wood-frame construction, strategic fire-resistant upgrades provide an immediate safeguard. For those looking to the future, alternative materials like concrete and CMU and alternative methods such as adobe and rammed earth may offer durable, sustainable solutions. However, it remains to be seen whether the increasing severity and cost of these wildfire events in California will lead to a more intense public and private drive to explore and implement alternative applications and methods so they progress from sporadic implementation to widespread adoption.
Let’s build a safer, more resilient future together. Contact Devonshire Construction today to learn more about fire-resistant construction solutions tailored to your needs.
