Interest increases to build tornado resistant homes

As of May 14, 2015, 7 of 8 fatalities caused by tornadoes occurred while the victims were inside homes. Two died in a building classed as a house and 5 died in buildings classed as manufactured homes.(Copyright: / 123RF Stock Photo)

New information reveals that 90% of U.S. counties experience tornado watches, and that’s causing some to say that it’s time to build tornado resistant homes.

In January, the Federal Alliance for Safe Homes released updated National Oceanic and Atmospheric Administration, Storm Prediction Center data showing that nearly 90% of U.S. counties experience tornado watches. According to FLASH this information underscores the point that building tornado resistant homes is not just beneficial to people in places where tornadoes are notorious.

FLASH reported that stronger homes and safe rooms can bring peace of mind to all who could potentially be in harm’s way as they wonder if their town will be next. The organization also stressed that  it wouldn’t cost more than $1 per square foot to build tornado resistant homes and forever reduce the pattern of death and destruction.

Building For Resilience

In the May 2013 FLASH paper, “Building Codes: The Foundation for Resilience” the American Society of Civil Engineers (ASCE), Federal Emergency Management Agency (FEMA) building science engineers, and leading academic researchers called for a new way of building to meet the challenge of saving lives while also preserving property in the face of tornado outbreaks. Their work, published as the Dual-Objective-Based Tornado Design Philosophy, is landmark in that it defies traditional assertions that from an affordability perspective you can’t build tornado resistant homes.

Investigations Into Collapsing Buildings

The research comes on the heels of field investigations that documented a pattern of disproportionate structure collapse in tornado outbreaks. The new thinking is that even small design changes can make a difference, and there are guidelines to estimate the tornado-induced loads. This will provide reasonable targets for designers to use in their future work. Homes built to these newer, research-informed guidelines will have the advantage of better wall bracing, improved roof tie-downs and overall stronger connections.

Tornado Event Realities

According to FLASH, this approach is buoyed by the finding from the National Climatic Data Center (NCDC) that most tornado damage comes from the milder tornado events because they are most common. Only 1% of tornadoes are of the violent types, called Ef-4 or EF-5. And, since 90 percent of all tornadoes never exceed EF-2, winds of up to 135 mph, wind-resistant building practices can save lives and dramatically improve building performance in tornado events.

“If we can put a man on the moon, we can keep a roof on a house, and our research demonstrates it is possible to design and build houses that protect people and structures from deadly winds,” said Dr. David O. Prevatt, associate professor of the University of Florida, Department of Civil and Coastal Engineering. “Techniques developed and implemented in Florida that have reduced hurricane losses can be applied and used in houses to also reduce tornado losses.”

Homes are long-term investments. Eighty percent of the nation’s home stock is more than 20 years old, and most of those homes  will be around for at least another 30 years. Thus, it’s important not only for individual families to make careful choices now as they rebuild, but each community must acknowledge its responsibility to rebuild in a resilient way, according to FLASH.

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http://www.spc.noaa.gov/climo/torn/fatalmap.php