Who Decides If A Home Should Be Built Elevated Or Not?
How high a home needs to be off the ground in coastal areas is guided by base flood elevation, a metric used by the Federal Emergency Management Agency to measure and map flood risk.
But experts have been warning for years that FEMA’s flood risk maps are outdated and don’t account for rising sea levels and other impacts of climate change.
A 2020 analysis by the nonprofit First Street Foundation discovered nearly 6 million homes that should have been identified as at-risk by FEMA but were not.
Besides outdated maps, surveys and other information used to calculate a home’s elevation are also not always accurate.
“A lot of people are in flood zones and they don’t know it,” Keenan said.
“The point here is that even if we have standards, a lot of times we’re either not enforcing it or we’re not meeting those standards because we don’t have the data to know whether we’re compliant or not,” Keenan said.
What Is A Stilt House?
Stilts, more formally called pier foundations, are pilings that raise a building off the ground anywhere from a few feet to a couple of stories. In many cases, the lower level is open to allow sand and water to wash through. In others, it’s enclosed with walls intended to give way to storm surge but leave the stilts standing.
“The lower level of these elevated homes are designed as breakaway, so that wave action essentially knocks the wall systems down,” Todd Wolter, president of a company that’s been building homes on Sanibel and Captiva islands in Southwest Florida for 37 years, told weather.com in an email.
“We saw these predominantly concrete structures, which are designed to 170 mph winds, perform reasonably well during a direct hit by Hurricane Ian.”
Not Everyone Can Afford A Home On Stilts
Elevated construction can add a considerable amount to the cost of home construction. And when it comes to rebuilding after a hurricane, a typical insurance policy isn’t going to cover it.
Things get especially tricky, Keenan said, when FEMA’s “51% rule” kicks in. That mandate requires that any damage beyond 50% of its value has to be brought up to all current codes if it’s rebuilt.
The rule is intended to help protect homes against future damage, but it also creates a financial burden in areas with older homes, like communities in Southwest Florida hit by Hurricane Ian last year. Keenan said it’s one reason people end up selling their destroyed properties instead of rebuilding.
“And that’s going to be part of a broader demographic shift, particularly for retirees and people on fixed incomes that simply won’t be able to entertain recovery from these shocks, time and time again,” Keenan said. “They simply won’t be able to afford it.”
There are nonprofit programs that can help with the cost, and more assistance may be on the horizon.
Climate Change Will Make Future Damage Worse
Global warming is driving rising sea levels that make storm surge and flooding worse. Scientists say climate change is also causing hurricanes to rapidly intensify more often and to carry more moisture.
All of that means there are several issues at play in building – or rebuilding – homes.
“It’s critically important to think about how we build. But it is many, many more times important and critical that people understand that the real question is where we build,” Keenan said.
“Because you can build a perfectly resilient home that’s got all the bells and whistles of design, engineering and technology, materials. But if you build it in a wrong location, those designs are quite limited and they’re certainly not going to protect you from the inundation of sea level rise.”