Wood or Brick? A lesson from wildfires in Los Angeles

Feb 18

After lasting more than three weeks and requiring beyond 7,500 first responders,[1] the wildfires in Los Angeles (LA) are mostly contained.[2] As the deadliest and most destructive wildfire in California’s history, it resulted in more than 29 causalities and approximately US$250 billion in economic losses.[3] California’s carbon emissions for January 2025 were estimated at 3.67 million tons of CO₂,[4] which is equivalent to 30 percent of monthly emissions from the transportation sector in 2022.[5] According to the American Lung Association’s 2024 Report, California has the poorest air quality among all other states, with over 18 million residents of LA and Long Beach breathing in the unhealthiest air in the country due to smog.[6] As a state that promotes environmental protection and carbon emission reduction, this fire sets a bad example for other states’ abilities to mitigating carbon emissions and protecting its residents. Despite widespread concerns about an inadequate wildfire emergency response, insufficient funding, and the prolonged dry season driven by rapid climate change, one critical aspect remains overlooked: the correlation between lumber houses and wildfires.

The United States (U.S.) has a longstanding history with wood. During the 17th and 18th centuries, European settlers found vast amounts of timber on the North American Continent, which were used to build houses with cheaper prices compared to the traditional European way of bricks and stones. Aside from the tradition of using wood and its aesthetic appeal, the price of timber in the U.S. is still cheaper than in Europe and East Asia. Likewise, its supply chain required when building wooden homes is well established in the U.S. The support from timber supply firms makes it difficult to alter, maintaining the status quo.

In 2021, roughly 92 percent of homes in the U.S. were built with wood.[7] Along with its cost-effective pricing, wood is viewed as more insulating and durable compared to brick, steel, or stone structured houses. Wood is a natural insulator due to its cellular structure, which contains air pockets that reduce heat conductivity. It has a thermal conductivity (lambda value) of approximately 0.13 W/mK, making it a better insulator than materials like brick (0.80 W/mK) and reinforced concrete (2.30 W/mK).[8] On the contrary, brick and concrete have higher thermal conductivity, meaning they transfer heat more readily and provide less insulation compared to wood. However, the durability of wood is misleading. Even though the U.S. average housing lifespan is approximately 130 years (most of them are wooden houses),[9] unlike brick and concrete, wooden structured houses suffer from moisture, pests, and fire risks--especially given the increasing concerns from climate change.

That being said, wooden homes will not be cheaper in the long run. In 2023, U.S. insurers lost $33 billion on personal home and auto insurance, driving many insurance companies to increase the price of home insurance to prevent the constant lost due to climate change.[10] One data shows that the average in insurance rates difference between owning a wooden house and a brick house is between 5-8 percent, meaning a homeowner can save up to 8 percent on insurance by choosing brick over wood.[11] In order to prevent the devastation of the house destructions, wooden structure may not be an economically viable solution in a long run since certain house insurers aim to prefer providing cheaper insurance premiums to non-wooden houses.[12]

Furthermore, wooden homes may exacerbate the already dexterous air quality in California. According to the principle of energy transfer, trees absorb large amounts of CO₂, which remains stored in their biomass even after they are cut down. However, if these trees are burned, the previously absorbed CO₂ is released back into the atmosphere, potentially accelerating climate change and impacting air quality. Therefore, cutting down trees to build more homes may not align with California’s air pollution prevention agenda.

Now, in this era of reconstruction, the Government of California must take decisive actions such as prioritizing long-term, cost-effective, and climate resilient solutions to combat the escalating wildfire crises. The stakes are too high for half-measures. Will Los Angeles seize this moment to forge a more fire and climate resistant future, or will history repeat itself in flames? Only time will tell but, as we all know, inaction is no longer an option.

[1] https://www.gov.ca.gov/2025/01/08/more-than-7500-firefighting-emergency-personnel-deployed-to-fight-unprecedented-los-angeles-fires/#:~:text=More%20than%207%2C500%20firefighting%2C%20emergency,Angeles%20fires%20%7C%20Governor%20of%20California

[2] https://www.nifc.gov/fire-information/nfn

[3] https://www.latimes.com/business/story/2025-01-24/estimated-cost-of-fire-damage-balloons-to-more-than-250-billion

[4] https://www.downtoearth.org.in/science-technology/scale-of-la-fires-is-unusual-compared-to-emissions-from-california-fires-for-january-over-the-last-20-years-mark-parrington#:~:text=Mark%20Parrington%20(MP):%20The,where%20the%20current%20situation%20stands.

[5] https://ww2.arb.ca.gov/ghg-inventory-data

[6] https://www.lung.org/research/sota/city-rankings/most-polluted-cities

[7] https://eyeonhousing.org/2022/07/the-share-of-wood-framed-homes-increased-in-2021/

[8] https://timberfinance.ch/en/wood-and-insulation/

[9] https://ascelibrary.org/doi/abs/10.1061/(ASCE)AE.1943-5568.0000401

[10] https://www.nytimes.com/2024/07/15/business/wildfires-home-insurance-building-standards.html

[11] https://www.cherokeebrick.com/blog/post/the-differences-between-brick-and-wood

[12] https://www.claimsjournal.com/news/international/2016/03/23/269612.htm?utm_source=chatgpt.com