I am working through the questions in Randall Munroe’s book, What If? that Randall declined to answer. My first answer, regarding the effects of extreme temperatures on human teeth, may be found here. Now, here is the second one.
Q. How many houses are burned down in the United States every year? What would be the easiest way to increase that number by a significant amount (say, at least 15%)?
Randall’s answer: “Hello, police? I have this website where people submit questions…”
My answer: Disclaimer: This content is for entertainment purposes only.
This is actually two questions. The first: how many houses burn down every year? And the second: how can that number be increased? The first one is almost a simple question. The relevant organizations keep very thorough statistics…just not thorough enough. The National Fire Protection Association’s annual report states that there were 271,500 reported house fires in 2013, resulting in $5.6 billion in damage. However, this is not what we’re looking for. We want to know how many of those houses burned down. I didn’t find any readily available numbers for that, but we can make a rough estimate.
$5.6 billion divided by 271,500 is about $20,600 in damage per house fire. Given that the median home value in the United States is $209,700, it’s clear that most of these houses are still standing. If we divide $5.6 billion by $209,700, we get 26,700. That’s not the actual number of homes burned down because the $5.6 billion includes the damage to all the homes that weren’t total losses, but half this number might be a good estimate. So let’s say for the sake of argument that around 13,000 houses are burned down each year.
The submitter wants to increase this number by 15%, or around 2,000 houses. This is a far more complex question involving causes of house fires and underlying social trends. However, I will note two interesting pieces of information. First, the NFPA report indicates that the number of fires actually has declined 15% in the past decade. That raises some interesting questions about what happened in that decade, but I think there is a simpler route.
According the National Interagency Fire Center, as reported here, an average of 2,857 structures are burned specifically by wildfires each year. That includes more than just houses, but 2,000 seems like a reasonable estimate for that. Therefore, the answer is probably–oh sorry, I’ve got to go. Smokey Bear just showed up.