Appurtenant Structures Contribute to Florida Storm Loss, Study Shows

During the 2004-2005 Florida hurricane seasons, there were anecdotal reports that appurtenant structures such as pool enclosures, garages, carports, and sunrooms substantially contributed to the total storm damage either directly through loss, or indirectly as wind-borne debris.

The Florida Legislature required the Office of Insurance Regulation to study this aspect of storm damage, and provided funding for this study. The Office contracted with an independent expert, Applied Research Associates Inc., to complete the study.

The OIR issued a final report titled, “Evaluation and Report on the Insurability of Attached and Free Standing Structures.” The report fulfills the requirements of Section 38 of Senate Bill 1980 passed by the 2006 Florida Legislative Session aimed at determining the impact appurtenant structures have on storm damage, and ultimately insurance costs.

The study showed the prevalence of exterior structures in Florida (on average one per site-built home, and three per manufactured home), as well as the relative value of these structures (10 percent of the total home value of site-built structures, and 19 percent of the total value of manufactured homes.). While the study did note exterior structures are highly vulnerable to hurricane damage, the study identified aluminum structures as most problematic.

The study concluded aluminum structures are not usually designed by professional engineers, and when these structures fail, the failings are generally catastrophic requiring complete replacement, which increases insurance losses.

“The mixture of factors that determine total storm damage is extremely complicated,” said Insurance Commissioner Kevin McCarty. “This study demonstrates that appurtenant structures, most notably aluminum structures, are an important component that increases storm damage costs. The State of Florida needs to design additional building code requirements for these structures in order to mitigate storm damage, and ultimately, lower the cost of insurance for our policyholders.”

Source: Florida Office of Insurance Regulation