There was a tornado just a few days ago in the Czech Republic (not far from where I live), and as far as I can see, houses did lose their roofs, or the shingles at least, but the structures remained mostly intact. Many houses have basements in which people could hide in relative safety. Five people died unfortunately, not sure how many of those were in their homes at the time. But I think those rather sturdy houses made of bricks did infact save a lot of lives, and prevented many more from totally losing their home.
To me it feels deeply illogical to build a house basically made of light wood frames when I know a hurricane can blow it away while I‘m inside of it. I‘m not sure about earthquakes, we have them of course, but they are less severe than in other areas in the world.
But, tornadoes here follow similar paths over a fifty year period. When I bought my house I found a hole in the fifty year tornado map and I’ve never had one come near me. Every couple decades the patterns may shift to other patterns, but generally speaking both the new patterns and old patterns have all happened in the last fifty years.
For a few decades the Swiss required building concrete nuclear fallout bunkers for every resident. This was relaxed only recently, but presumably it was doable for five decades. https://www.reuters.com/article/us-swiss-bunker/swiss-relax-...
It seems a concrete dome would also work if digging a bunker is too expensive. Yes it’s not pretty, but not being afraid of dying during the next hurricane season must be worth something. A small dome can’t cost much.
https://www.icfmag.com/2012/09/tornado-resistant-concrete-ho...
What was your source for this information?
There's a saying: It's not THAT the wind is blowing,it's WHAT the wind is blowing.
A log cabin would not have survived the worst areas of it I don't believe.
Hurricanes are far more destructive and many spawn tornadoes. About 44% of Americans live in a Hurricane zone.
Add earthquakes and fires maybe 60~70% of Americans live in a place with reoccurring natural disasters.
EF4 or EF5 tornadoes are around 2% of those in the US (https://en.wikipedia.org/wiki/Tornadoes_in_the_United_States), which means any state with more than 34 or so a year can expect to see at least one. That accounts for 14 states with a combined population of about 106 million people. That's approximately 32% of the total US population.
8%-ish of tornadoes rate EF3. At which point any state with seven or more a year should expect at least one in the EF3-5 range (yay, birthday paradox!). That's 32 states totaling 270 million people - 82% of the US.
Looking at this image (https://en.wikipedia.org/wiki/File:Improved_Average_Annual_T...) from the wikipedia article you linked shows this, with New Orleans, Atlanta and Miami being outside their state's main tornado zone and Houston and Chicago right at the border of high-tornados and medium-tornados.
I think the overall point is sound, though. A huge chunk of the US population is in territory regularly subject to strong tornadoes.
Also, I would beg to differ that this map puts Chicago at the edge of a high-tornado zone. It's solidly in one, as is Kansas City.
But your larger point stands.
> Plus many areas are subject to tornados and hurricanes when it is rather pointless to build anything that lasts 100 years. On that time scale the house will be destroyed or badly damaged in any case.
Tornadoes yes, hurricanes, no. Build strong and heavy, with durable steel shutters for all windows and very secure doors, and there's no reason your home can't survive hurricanes with minimal damage. Flooding is another matter, entirely.
1,000 sq mi is about 640,000 acres, so that's .0000015 tornadoes per year per acre. If I've got my math right, that's about a 99.9% chance that your 1 acre plot will not be hit by a tornado in 1000 years, if you live in the Atlanta area, which is only a middling high-probability area. (https://weather.com/storms/tornado/news/tornado-odds-of-bein...)
Hurricanes are generally only a coastal problem, although flooding is a fairly large issue everywhere. (Don't get a house in a low lying area. Please.)
Earthquakes are mostly a West Coast thing, modulo New Madrid (pronounced "mad-rid") and various oil drilling operations. But then there's fires and termites and everything else.
There are plenty of hundred-year-old houses all over the US, as well as plenty of newer ones that could last more than a century with proper maintenance.
Few houses today are built to last that long, though, because it's more expensive but doesn't add anything to the purchase price like granite countertops. Stick frame on slab construction is pretty close to mini-maxing housing construction as the article describes (even in areas where slab foundations are geologically idiotic).
Anyway, when you get down to the second-to-last section of the article, remember that, past a certain point, efficiency is the enemy of resiliency.
I appreciate your attempt to come up with realistic numbers, but you are making the assumption that each tornado only affects a single acre. As discussed in the article you linked, if a tornado touches down, it frequently causes destruction for a path of several miles, making this a faulty assumption.
They have earthquakes in e.g. Italy and Turkey too, you know.
There are certainly earthquake (and hurricane) areas but the majority of the US population does not live in those. I'd need some risk/benefit analysis and actual data before believing they are even a factor in the equation for most people and areas. I can think of 100 other possible reasons (eg historically people moved frequently, or it was simply cheaper to rebuild than maintain as building standards/expectations change frequently, or in the cities you anyway expect someone to come in and buy up old building stock and rip it all down to put something bigger in, or ... ).
See ASCE 7-16 Minimum Design Loads and Associated Criteria for Buildings and Other Structures, For wind: Chapters 26-31 for 144 pages of wind load design criteria. (California Building Code and International Building Codes recognize and point to that standard)
Of particular note, is a concept called "Basic Wind Speed" which is derived from mapped values. What you'll find is that its intimately correlated with hurricane landing. Most people live on the coast in the US where the wind speed is highest. Depending on the risk category of the building, a typical value on the West coast is ~105 mph. On the east coast, it vaires by latitude from ~115-200 mph, increasing in all the areas that get hit by hurricanes. To address your skepticism, I assure you things like hurricanes are undeed a significant design concern.
The seismic load is similar.
Both loads are fundamentally designed to give a defined risk of failure from storms and earthquakes with particular recurrence intervals ranging from 50-100 years. (Offhand, I believe this value is ~1% for total collapse with a much higher risk of damage.). It is indeed carefully weighted and considered balance between risk reduction and feasibility, and indeed, having less than 1% risk for intervals over 100 years starts to get rather difficult. We still require it for schools, police stations, and emergency gathering locations and the like, but not normal houses.