Five Climate Change Resilient Building Materials for California Homes

In our post “Building Climate Change Resilient Homes in California,” we outlined the many natural disasters that will affect Californians as the climate continues to change. Unfortunately, the many disasters to which California is prone to will only increase in number and intensity in coming years. From flooding in wetlands and erosion along the coasts to supercharged wildfires and record heatwaves, Californians are uniquely at risk from disaster. Not only do natural disasters have the capacity to destroy homes, but they can also wipe out power grids, our water sources and other critical infrastructure. Because of this, California homeowners and architects have begun searching for ways to climateproof their homes. This means choosing climate change resilient building materials as well as integrating passive or off-grid capabilities. With some ancient and others innovative, follow below to learn about five climate change resilient materials for homes in California.

Why We Need Disaster Resilient Homes in California

The way we organize our built environment makes natural disasters due to climate change more likely to impact infrastructure, destroy communities and place human lives at risk. In a June 2021 broadcast for the NPR program All Things Considered, Rebecca Hersher references recent research into housing and disaster risk. According to a new study, “more than half of the buildings in the contiguous U.S. are in disaster hotspots.” Herscher notes that today, “tens of millions of homes, businesses and other buildings are concentrated in areas with the most risk from hurricanes, floods, wildfires, tornadoes and earthquakes.”

California is More at Risk than Other Areas of the US

This is especially true in California, where we continue to build homes along coastlines at risk of significant sea level rise and in inland areas at risk of wildfires. A recent KQED broadcast noted that “more than 11 million Californians, roughly a quarter of the state’s population, live in high-risk wildfire areas known as the wildland-urban interface.” LA County appears to be most at risk of disaster, according to data compiled by the Federal Emergency Management Agency.

The January 2021 The LA Times article “The riskiest place for a natural disaster in the U.S.? You’re living in it, L.A.” explains. The LA Times article notes that FEMA calculated risk for eighteen different types of natural disasters in each county across America. These include “earthquakes, hurricanes, tornadoes, floods, volcanoes and even tsunamis.” Of the three thousand counties surveyed, “Los Angeles County earned the highest ranking in the National Risk Index.” Riverside County and San Bernardino County -- both in Southern California -- also made the top ten.

Five Natural Disaster Resilient Materials for Your California Home

In our post “Preparing for Your Home for the Next California Wildfire Season” we underscored the importance of hardening your home and its surroundings against wildfires. This is also true for flooding, high winds, heat waves and other natural disasters in California induced by climate change. However, hardening homes against flames and floodwaters is not the only way to protect them from natural disasters.

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We also noted the importance of considering disaster risk before building your house, choosing resilient materials and introducing off-grid capabilities in case of power outages, grid failure or water contamination. Homeowners in California must focus on ways to make their homes safer and more self-reliant by building better structures. Below, we detail five building materials that can help California homeowners do just that! While some are innovative and brand new, most are actually natural and ancient. However, all are being used by architects and builders in exciting ways that protect homes from disaster and from the changing climate while limiting our carbon footprint.

#1 ICF or Insulated Concrete Forms

First on our list of climate change resilient building materials is ICF or insulated concrete forms. For those unfamiliar with the building material and technique, John Cradden explains in his article “The PH+ guide to insulating concrete formwork” for Passive House +. Cradden writes that “insulated concrete formwork is a method of building construction using lightweight and hollow insulation forms that fit together and are then filled with concrete.” After the concrete has set, it “becomes a high-strength structure and the formwork remains in place as thermal insulation.” ICFs were invented in the 1960s by designer Werner Gregori, who was working as a general contractor at the time. In the decades that followed, ICFs were not very popular in the United States.

However, “thanks to the demand for greater new-build energy efficiency, ICF has come much more into focus within the construction industry in recent years.” It is now commonly used “in the passive house sector.” John Cradden notes that because the concrete of ICFs “sets in direct contact with the insulation, [it] therefore delivers both airtightness and prevents thermal looping from undermining insulation performance.” This makes ICF homes attractive from an energy-efficiency perspective.

How Insulated ConcreteForms Can Protect California Homes from Wildfires, Winds and Floods

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ICF homes are also incredibly strong and disaster-resilient, making the building technique ideal for homes in California. In the article “The Benefits of Using ICF: One Architect’s Perspective” for Architects Magazine, Mark Ginsberg, FAIA of NYC firm Curtis + Ginsberg Architects explains. According to Ginsberg, ICF is not only energy-efficient but also offers superior “structural integrity and sound absorption/reflection.” He notes that “‘ICF provides a simple way to build an energy-efficient, cost-effective envelope’” that also protects a home from penetration by fire or flood. This airtight envelope makes it incredibly difficult for flood waters, wind and/or embers to access the interior of the home. As such, ICF homes are well-protected against wildfires, hurricanes and other types of natural disasters.

Writing for The Washington Post in “Designed for disaster: These homes can withstand a Category 5 hurricane,” Matthew Cappucci elaborates. Cappucci quotes Mike Kennaw, VP of Fox Blocks Insulated Concrete Forms, which “helps build hurricane-proof structures” across the US. Constructing homes with insulated concrete forms as part of a “steel-reinforced wall assembly” produces homes that “have a very high wind test rating.” Because the concrete used in these ICF walls “can be one hard shell,” there are “fewer failure points.” This makes the home “more impact-resistant than traditional wood homes” and -- as mentioned above --better protected against wildfires.

#2 Superadobe

In 2018, Southeast University, Dhaka researchers Razia Kamal and Saifur Rahman published their paper “A study on feasibility of super adobe technology –an energy efficient building system using natural resources in Bangladesh” through Institute of Physics Publishing. Their study defines superadobe and evaluates its feasibility as a construction material around the world. According to Kamal and Rahman, superadobe is “a form of earth bag construction using sandbag and barbed wire technology.” The technology was developed by Iranian-American architect Nader Khalili in 1984. Khalili also founded CalEarth and pioneered the Ceramic Houses system.

Kamal and Rahmannote that superadobe is low in cost and low in environmental impact, making ita sustainable building choice where available. Superadobe is air tight, offering good insulation, protecting from extreme heat and improving energy efficiency within the home. Best of all, superadobe is “statically strong, durable, and resistant even to extreme weather conditions and natural catastrophes like flood, windstorm, hurricane, fire, and earthquake.” As such, superadobe is an exceptional green building material for climate resilience inareas like California which are prone to nearly all of these natural disasters and weather events.

How Superadobe Can Protect Homes in California from Wildfires and Earthquakes

California has experienced a number of devastating earthquakes in the last hundred years, with the Northridge, Cape Mendocino and Kern County earthquakes some of the most devastating. In 2021, however, Californians lay in wait for “The Big One” -- an intense quake expected to imminently hit the San Andreas fault. According to LAist writers Arwen Champion-Nicks , Misha Euceph  and Mary Knauf, “​​The Big One will be at least 11 times stronger than the Ridgecrest earthquake and 44 times stronger than Northridge.” In her article “What is ‘Superadobe’?” for BBC Future, Megan Frye writes that superadobe could help protect California homes during The Big One.

Frye notes that “superadobe structures have been shown to withstand devastating natural disasters.” Following the 2015 Nepal earthquake and the 2017 hurricane in Puerto Rico, “superadobe buildings were still standing.” Because of this, Fryewrites that there “are now countless superadobe homes around the globe, ranging from emergency shelters to luxury homes.” She notes that superadobe structure shave already lived through earthquakes and fires in California specifically. Infact, a superadobe “building at southern California’s educational nonprofit the Ojai Foundation...survived the deadly Thomas Fire of December 2017 to January 2018.”

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#3 Straw Bales

In 2019, Stefano Cascone, Renata Rapisarda and Dario Cascone published their paper “Physical Properties of Straw Bales as a Construction Material: A Review” through the Multidisciplinary Digital Publishing Institute. Their review focused on how straw bales are currently used in construction around the world and how they could become commonly used in the future. Cascone, Rapisarda and Cascone write that “tests performed by multiple authors show that the use of straw bale buildings as a common practice is a solid possibility” due to effectiveness and sustainability.

They write that when used in domestic dwellings, “straw bales can provide significant benefits interms of costs, human health, and environmental sustainability.” The authors identify several studies conducted around the world that “have underlined the remarkable properties of straw bales as [an] insulation and construction material, highlighting their ability to achieve excellent living comfort.” Many architects advocating for sustainable construction continue to “encourage their use...even though straw bale constructions do not have a significant place in current building practices.”

Using Straw Bales to Make California Homes More Disaster Resilient

Architects and homeowners in California, however, have begun catching on to the many benefits of straw bale construction -- particularly those that protect against natural disasters. In her article “This Building Material May Hold the Key to Surviving Environmental Disasters” for Architectural Digest, Dakota Kim explains. Kim writes that straw bale construction is “gaining popularity inparts of California” because “straw bales have proven themselves not only worthy fire adversaries, but also relatively stable during tornadoes and seismic shaking.”

Used in conjunction with “other fire-retardant features” like “steel roofs...plastered soffits” and“preventative gullies,” straw bales are especially helpful for protecting California homes from wildfires. Referencing tests conducted by the Ecological Building Network, Kim writes that straw-bale walls “clad in earthen plaster” can protect against both internal and external fires. In fact, “a straw-balewall clad in earthen plaster meets hospital-grade two-hour fire resistance requirements.” Straw bale walls surrounded by stucco meet “one-hour, standard commercial grade fire resistance requirements.” In 2015, straw bales were finally listed on the IRC for single family houses, meaning that “most Americans [can] build straw-bale homes” legally.

#4 Stucco

Stucco is another traditional building material capable of protecting homes from wildfire damage through resilient design. Stucco has been used as a coating for buildings for thousands of years, applied to homes in Ancient Greece and Ancient Rome. Stucco was originally applied to both interior and exterior walls as decoration -- or as a canvas for decorative elements.

Today, stucco is applied to homes across California to protect them from wildfires and other disasters. For those unfamiliar with this building material, Juan Rodriguez explains in his article “What Is Stucco Material?” for The Balance Small Business. Rodriguez writes that stucco is “made from cement, sand, and lime and hardens into a highly durable material that requires little maintenance.”

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In their “Homeowner’s Guide to Fire-Resistant Home Construction” for Firefighters United for Safety, Ethics, and Ecology, Rich Fairbanks and Timothy Ingalsbee endorse stucco as a way of hardening homes against wildfires. Fairbanks and Ingalsbee write that “stucco is probably the best material for WUI [wildland–urban interface] wall construction.” This is because stucco is “simply a fine grade of cement, a sort of artificial stone that does not burn and is not a good heat conductor.”

How Stucco Helps Harden Homes Against Wildfires

Innovative California designer Abeer Sweis also recommends that Californians consider stucco to protect their homes from wildfire. Bonnie McCarthy quotes the Santa Monica-based designer -- a partner at firm Sweis Kloss -- in her article “Safety, style and sustainability: What new construction looks like in a fire zone” for The LA Times. Sweis suggests stucco as an effective first line of defense, which is typically the most important for saving a structure. This is because “‘if you can resist that first impact, and if nothing in the house itself burns, then the fire tends to keep moving.’”

Referencing a “SweisKloss project that survived a fire in Ojai last year,” Sweis describes her strategy. According to McCarthy, Sweis “encased the house in what she calls an ‘envelope’” of stucco. Sweis coats the exterior of the home with stucco that has a “smooth plaster finish, which is Class A rated as having fire-resistant properties for up to one hour.” Abeer Sweis notes that this stucco “‘goes all the way down to the bottom [of the exterior walls] and is flashed underneath.’” That way, there is no “‘a place for the fire to sneak in.’”

#5 Bamboo

Bamboo has been used as a building material for thousands of years across Asia. In recent years, architects in the US and Europe have also favored the grass -- primarily forits sustainability and durability. In an interview with Yasmeen Lari for Dezeen, Jennifer Hahn notes that bamboo “sequesters C02 throughout its life,” making it an excellent green building material. In the article “Bamboo Might Just Be the Construction Material of the Future” for Architectural Digest, Beau Peregoy agrees, describing it as “the perfect natural building material.” According to Peregoy, bamboo “can grow up to four feet per day, and, when harvested, it regrows without having to be replanted.” Perhaps best of all, bamboo is “two to three times stronger than steel.”

How Bamboo Could Protect California Homes from Earthquakes, Floods and Strong Winds

The plant’s strength is the main reason why it performs well against natural disasters. In his article “A Storm-Resistant School Concept in the Philippines” for Dwell, Tim Hanrahan describes how bamboo protects one structure from typhoons. LA design studio MAT-TER designed a school made primarily from bamboo after “Typhoon Haiyan devastated the Philippines with over 6 million people displaced from their homes and 4,500 schools destroyed.” Bamboo was chosen because the material is “accessible...in the Philippines” and is “strong enough to withstand typhoons, earthquakes and floods.” The design for this building is open-source, meaning that it could “be used for other disaster-prone areas across the globe” -- like California.

Element Homes Builds Disaster-Resilient Homes for California Homeowners

In our post “How to Rebuild Your Home After a Wildfire,” we explained why Element Homes is uniquely qualified to help Californians build disaster resilient homes that can withstand climate change. We noted that the head of development at Element Homes has over twelve years experience helping homeowners build disaster-proof homes. Well-respected across the Golden State, Element Homes is one of California’s premier design-build firms. Our team has many years of experience rebuilding homes lost to wildfire, ensuring that each build is protected in the future.

Because our team is local to the Greater Los Angeles Area, we understand the many risks California homes face due to climate change. From homes along the Malibu coast to those in the San Bernardino Mountains to those nestled in the mountains of California, Element Homes constructs climate proof properties. As we explained in “How to Rebuild Your Home After a Wildfire,” the Element Homes “team also knows wildfire hardening techniques and recent changes to state legislation.”

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