Before Hurricane Irma roared into the South Florida hurricane zone this week, there was Hurricane Andrew.

That intense Category 5 hurricane, a compact buzz saw that ripped the roofs off thousands of South Florida homes 25 years ago, was so catastrophic that it led to sweeping changes in the insurance industry, weather forecasting and disaster response.

And Floridians — shocked by acres of flattened houses — rewrote the state's building codes, making them the toughest in the nation.

Now, as memories of the horrendous destruction of Aug. 24, 1992, grow dim, the lessons learned from Andrew may be fading, too. The building codes once hailed as the gold standard other states should emulate are under assault.

At the core of that growing dispute is a simple calculation: the tougher the building code, the more it costs to build a home.

Florida's codes dictate construction methods, require wind testing and mandate extensive training and oversight for inspectors. Those standards, home builders argue, can add unnecessary costs that don't amount to a hurricane-proof home. Insurers and home owners' associations say the tough codes save money in the long run.

This year, alarm bells went up all over the state capital, Tallahassee, when the Republican-led legislature and GOP Gov. Rick Scott passed a new law that untethers Florida's code from international standards and requires fewer votes for the Florida Building Commission to make changes to the building codes.

Opponents said it opened the door for the commission, which is dominated by home builders and contractors, to weaken the codes.

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Craig Fugate, the former head of the Federal Emergency Management Agency, the federal agency that responds to disasters, said Florida's latest move sickened him.

"I don't think builders are inherently evil people, but you've got to look at what their business model is," said Fugate, who led Florida's emergency management agency before heading up FEMA. "The quicker they get to sell a home with the least amount of cost and the least time delays increases the money they make."

Republican leaders and the state's home builders say such concerns are overblown. Jeremy Stewart, a Crestview, Fla., developer and president of the Florida Home Builders Association, noted that the bill passed in Tallahassee did not change a single building code. Instead, he said, it simply modernized the process for updating the code.

There's no reason, he said, to think developers will use the new process to weaken the state's building codes, and bristled at the suggestion that builders simply seek to cut costs.

"That's absolutely false and misleading," Stewart said. "There's not a single contractor that I know of in the state of Florida that does not want to be operating under the most stringent code, that's not concerned with the well-being of our customers."

A building boom and haphazard codes

For Florida's builders and building officials, life could be defined as "before Andrew" and "after Andrew."

The Florida peninsula juts straight into the tropical storm-prone area of the Atlantic known as "hurricane alley." Before Andrew, South Florida hadn't suffered a direct strike from a major hurricane since Hurricane King in 1950, said Michael Goolsby, director of building code administration for Miami-Dade County.

Year after year, hurricanes swept by, either slipping up the East Coast or falling apart in the Gulf of Mexico. "That's more than 40 years," Goolsby said. "That brings about a certain level of complacency."

Meanwhile, construction boomed and the state's population swelled. To curb haphazard home building, local governments created building codes, but they varied from county to county.

"I've heard stories that there were up to 26 codes that were being used," Stewart said.

What codes did exist were frequently ignored. Ricardo Alvarez, a former state and federal building inspector, said contractors cut corners as the storm drought dragged on. Instead of using sturdier plywood under roofs, they used a cheaper, flimsier version of particle board. Instead of using roofing nails, they used staples.

Then, Andrew hit.

Its 145 mph winds tore apart the working-class suburb of Homestead, reducing entire city blocks to rubble. Debris torn from roofs or lifted from the ground turned into deadly projectiles, smashing windows and impaling people.

The numbers were staggering: 25,524 homes destroyed, another 101,241 damaged and more than 40 people killed, according to the National Hurricane Center.

All told, Andrew led to $24.5 billion in insured losses, the costliest disaster in U.S. history at the time. Only Hurricane Katrina in 2005 and the terrorist attacks of Sept. 11, 2001, cost more, according to the Insurance Information Institute. Andrew's costs were so high that 11 insurance companies went bankrupt.

Andrew forced Florida leaders to examine disaster response, insurance laws and evacuation procedures. The legislature created a state catastrophe fund, which now stands at $17.6 billion, to help cover losses from hurricanes. Lawmakers created Citizens Property Insurance Corp., a not-for-profit, government-run insurance company that covers more than 470,000 homeowners who can't find insurance on the private market. And the state changed its procedures for evacuations, communication during disasters and the role of emergency responders.

They took the hardest look at the building codes. Why, they wondered, did thousands of roofs lift from their houses?

Investigators founds dozens of flaws but zeroed in on gables, the triangular areas of a house that sit on top of a masonry wall and under an arched roof. Gables could be made from wood at the time, which investigators realized had created a glaring weakness easily exploited by hurricane-force winds. When water and wind got through the gable, the wind could lift up the entire roof or whip through the house, blowing out windows and doors.

"When the wind came along, these gables folded in like a hinge," Goolsby said.

Andrew drives a new approach

Over the next decade, state leaders studied construction standards, negotiated with home builders, and finally, unveiled a statewide, mandatory building code that took effect in 2002.

The lessons of Andrew drove many of the building code changes. Inspectors now had to approve building plans and sign off on all phases of new construction. The entire "building envelope" of a home — every window, door, skylight or any point that could let in wind — had to undergo testing and approval.

The first major test of Florida's new standards came in 2004, 12 years after Hurricane Andrew. That year, four hurricanes — Charley, Frances, Ivan and Jeanne — walloped the state in one hurricane season. The newer homes, built under the tough code, survived.

A report from FEMA found that homes built after the codes were put into place performed better than the older stock. A separate report from the Insurance Institute for Business & Home Safety found that owners of post-Andrew homes filed 60% fewer insurance claims and the severity of those claims was 42% lower.

"That is not a marginal change," said Julie Rochman, CEO and president of the institute. "The codes proved themselves out beautifully."

Florida scales back

Rather than embrace the success of the new codes, however, the state started walking them back.

The Florida Building Commission — a 25-member board appointed by the governor that includes builders, engineers and inspectors — analyzed data from the four storms and decided to recalibrate how much wind a Florida home would need to withstand.

“The general feeling was that in 2005 we were over-designing," Jack Glenn, the retired director of technical services for the Florida Home Builders Association told the Miami Herald. “We needed to relax a bit because there is a cost impact.’’

Different areas of the state receive different winds on average. The lower the wind, the lower the building requirements. After the 2004 season, state officials redrew the maps. The state increased the wind loads in one area — South Florida — but reduced them by 20% in much of the rest of the state. Jacksonville, on Florida's northeast coast, largely spared by the four hurricanes, saw its wind loads reduced as much as 35%.

Further tweaks to the code led to a startling change in 2015. The insurance institute that had praised Florida for its 2004 hurricane season performance and its tough building code downgraded the state's code from the top spot to second place, behind Virginia.

This year, builders pushed for even bigger changes.

States around the country base their building codes on those developed by the International Code Council (ICC). The council examines the latest technology and uses experts from around the country to update its codes every three years.

Florida had timed its process to the ICC updates. Every three years, the state would adopt the new ICC codes. The Florida Building Commission would remove portions that didn't affect Florida, such as standards for roof-top snow accumulation, and add Florida-specific provisions, such as strict high-wind requirements.

But during the legislative session this year, legislators pushed for big changes. One proposal called for state officials to freeze the code as it stands, with only occasional updates. Another proposal called for a six-year cycle of updates instead of three.

Leslie Chapman-Henderson remembers Andrew vividly. She managed Andrew-related insurance claims for Allstate. The legislature's direction alarmed her.

"We were watching these bills fly out of committees unanimously and we’re thinking, ‘This is not good,' " said Chapman-Henderson, who is now president of the Federal Alliance for Safe Homes.

The negotiations ended with a compromise. Florida's building codes would still be updated every three years, but they would no longer adopt the ICC codes. Instead, Florida would keep its current code and pick and choose which parts of the ICC code to adopt.

The law also reduced the number of votes required for the state's building commission to change the building codes. Now a code change requires just two-thirds of the board to support the change rather than 75%. That worries Fugate, the former FEMA director, who said the commission is already stacked in favor of builders and contractors, who account for 10 members of the 25-person board.

Kerri Wyland, a spokeswoman for Gov. Rick Scott, said the law reduces "burdensome regulations while maintaining Florida's gold standard of safety and innovation through an efficient and effective building code adoption process."

Jimi Grande, senior vice president of the National Association of Mutual Insurance Companies, fears state officials will cherry-pick which technologies to adopt and which to ignore. Grande said insurers are very nervous about that change, which could lead to higher premiums for Florida homeowners.

"What they are doing is tying themselves to a new system that won't keep up with science and technology," Grande said. "That's what's scary about it."

The 2017 hurricane season ends Nov. 30 and the National Oceanic and Atmospheric Administration has predicted as many as 19 named storms could develop in the waters around the United States. As always, Florida is in the crosshairs. That has Chapman-Henderson worried.

"We are still in a state of shock that the most hurricane-prone state in the country would retreat from its world class building code system," she said. "Florida was the good child. Now they're on the path that led to the failures of Hurricane Andrew."