The Codes are Working: Newer Buildings Tended to Protect Better During Ian - November 2022

Fri, Nov 25, 2022 at 8:00AM

John Hellein, FRSA Educational & Research Foundation Director

At the October Florida Building Commission meeting in Gainesville, Dr. David Prevatt of the UF Department of Civil Engineering, presented preliminary findings to the Commission on the effects of Hurricane Ian to buildings in the area of impact.

Given the extent of the damage from Ian, it was sobering to hear Dr. Prevatt characterize the storm as a “moderately strong wind event.” Looking at the reported wind speeds around landfall, we can understand the reason for this characterization: despite Ian’s 150 mph sustained winds – which apparently occurred offshore – the top three-second sustained gusts were around 120 mph. Prevatt noted that the actual wind speeds experienced onshore were significantly below the design speeds, which were in the 150-to-160 mph range (see map at the bottom of page 13).

Newer Construction Performed Better

Municipal buildings and schools in the area of impact performed very well according to Prevatt and, in general, newer construction – structures permitted or improved under the Florida Building Code that was first implemented in 2001 – performed better than older construction. Prevatt’s presentation included the below photo of Fort Myers Beach, posted by Professor Michael Bruneau of the State University of New York. The photo indicates the years in which houses, or what remains of them in many cases, were built or improved. The circled, still standing house directly on the beach was built in 1990 but “redone and expanded” in 2020. A subsequent post by Bruneau listed, by year built or improved, many of the properties in the photo (the ones he was able to get information on) and whether or not the home on the property survived.

ian photo
 
■ Of the 13 listed properties that survived the storm, 12 of them were built or improved after 2013.
■ Of the 16 properties that were destroyed, all of them were built before 1979.
 
Of course, the physical forces at work from wind and storm surge during a hurricane are complex, so it is typically difficult to draw crystal clear conclusions, but there is strong evidence that newer construction, built under stricter codes, performed better than older construction.
 

Unsecured Mobile Homes

Finally, the Commissioners heard about the “extreme damage” caused by wind and flooding to mobile homes residing on stacked and unsecured cinderblocks. The reality faced by the people living in such mobile homes – as well as by the rest of us – is that they are the people least in a position to cover the expenses involved in improving the safety of the homes in which they live. Possible solutions include programs to help residents strengthen the foundations of their mobile homes and forbidding future placement of
mobile homes in flood prone areas.
 

FRM

 

 

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