MIAMI — After a catastrophic Hurricane Andrew revealed how lax building codes had become in the country’s most storm-prone state, Florida began requiring sturdier construction. Now, experts say a monstrously strong Hurricane Irma could become the most serious test of Florida’s storm-worthiness since the 1992 disaster.
“If it was to hit with 185 mph (298 kph) winds, I don’t even know how the buildings under the new code are going to fare. That’s a storm beyond comprehension,” said Allen Douglas, executive director of the Florida Engineering Society.
Andrew razed Miami’s suburbs with winds topping 165 mph (265 kph), damaging or blowing apart over 125,000 homes. Almost all mobile homes in its path were obliterated. The damage totaled $26 billion in Florida’s most-populous areas.
The acres of flattened homes showed how contractors cut corners amid the patchwork of codes Florida had at the time. For example, flimsy particle board had been used under roofs instead of sturdier plywood, and staples had been used instead of roofing nails.
“It was the conclusion by engineers and economists that the building code was the core reason that Miami suffered the costly damage that it did,” said Leslie Chapman-Henderson, president and CEO of the nonprofit Federal Alliance for Safe Homes.
In Andrew’s wake, Florida mandated the most stringent building codes in the U.S. Since 2001, structures statewide must be built to withstand winds of 111 mph (178 kph) and up.
The Miami area has even higher requirements. Broward and Miami-Dade counties are “high velocity hurricane zones” where structures must withstand hurricane winds of at least 130 mph (209 kph); critical infrastructure buildings must withstand winds of 156 mph (251 kph) and up.
The codes call for shatterproof windows, fortified roofs and reinforced concrete pillars, among other specifications. Updated codes slated to take effect in January add requirements for minimum elevations above expected flood levels.
The improvements showed their value when new mobile homes fastened more securely to foundations fared better throughout four hurricanes that hit Florida in 2004, said Monica Ningen, chief property underwriter for the U.S. and Canada at Swiss Re, a Switzerland-based reinsurance company.
Irma, however, worries experts. The dean of the University of Miami’s College of Engineering, Jean-Pierre Bardet, voiced concerns not immediately answered by the codes: Will high-rises withstand flying debris? Do people understand the forecast shows Irma’s potential path, not where its strongest winds will blow? Do building codes ensure a quick recovery? Have some areas over-compensated?
Bardet had the same answer, over and over: “That is a good question.”
Newer buildings aren’t expected to survive unscathed. In 2005, Hurricane Wilma’s Category 2 winds blew out windows in new Miami high-rises that met the updated code.
“The code isn’t perfect,” said former Federal Emergency Management Agency chief Craig Fugate, who led Florida’s emergency management division during the 2004 and 2005 storm seasons. “It’s not always going to provide protection needed, especially for schools, firehouses, 911 centers and other types of critical infrastructure, even though those are critical functions that we should have hardened for wind and flood damage.”
This year, Florida decided to review its building regulations every three years, instead of automatically adopting design updates approved by the International Code Council. No standards were weakened in the legislation, but critics argued the new law no longer obligated Florida to incorporate resiliency innovations into the codes.
Wind speed is far from the only storm hazard. As Hurricane Harvey demonstrated in Texas last month, heavy rainfall and storm surge can cause flooding far beyond the reach of a hurricane’s strongest winds.
Highways along evacuation routes are built at higher elevations to prevent flooding, but the roads and sewage systems in some Miami-area neighborhoods are inundated during high tides or rainstorms. After Wilma, it took weeks to restore power to some areas.
“You can cripple a region without power, communication, water,” Bardet said. “It’s about resilience — how quickly you can rebound from a state of disaster, how quickly you can restore services for everyone so everyone can go back to work and go back to their normal lives.”
Swiss Re now estimates the combined residential values in three Miami-area counties are roughly $660 billion, and commercial values are around $550 billion.
Property owners should assume responsibility for ensuring resiliency for their own properties, instead of expecting the state or federal government to pick up the pieces if Irma hits, Ningen said.
“Building codes matter, but building codes alone are not going to save a house from a Category 5 hurricane,” she said.