HED: Hurricane Hardening
By Jeff Bergmann, PE, Senior Project Manager
Hurricane hardening — what is it? Why are counties and cities requesting hardening evaluations? Why should a commercial property owner or private business be interested in an evaluation? Does it result in a reduction in the property insurance? What benefits will it yield?
These are the questions that come to mind during discussions of evaluating an existing structure for hurricane hardening. Just what the heck (those who know me are used to much more vibrant language) does that mean?
“Hurricane Hardening or Storm Hardening is the process where construction is used to create new infrastructure or retrofit existing infrastructure such that it is more capable of withstanding extreme weather events.” It “involves physically changing infrastructure to make it less susceptible to damage from extreme wind, flooding, or flying debris.”
In other words, it is a building’s or facility’s ability to remain in operation, or have minimal or no downtime, during and after storm events.
Hardening evaluations can vary from a single building structure, such as a residential home, to an entire infrastructure, such as the electrical transmission and distribution system of the State of Florida.
For this article, we will concentrate on existing commercial and institutional building facilities.The evaluations are typically performed by a two-person Structural Engineering team and a two-person Mechanical/Electrical Engineering team to assess an existing building’s ability to withstand a storm. Structural consideration is given to the building envelope, wall type, roof type, windows, doors, exterior drainage, landscaping, and any other observed potential problem in a high-velocity wind event. Mechanical and electrical considerations include locations of air handling units, water supply, critical electrical/ mechanical equipment, if there is emergency generator power and, if not, what size is appropriate for the building’s planned use during and after a storm event. The team will recommend improvements to the structural components and utility infrastructure (internal and external) to increase the resistance and resiliency of the facility during and following a storm event.
The advantages of having a building (or facility) hardened are continual use, no loss of functionality of the building, and a decrease in insurance rates for storm and flood mitigation (as may be applicable — this should be discussed with an insurance agent.). With sustained use, there is sustained income. Hardening is a preferred alternative to reconstruction or replacement of a structure and the most cost-efficient approach to storm-loss mitigation.
(Before) Interior framing of a building that does not meet code.
During the 2004 and 2005 storm seasons, there were businesses within Palm Beach County, that were without electrical power for two-three weeks. Once power was restored, other factors such as compromised HVAC and building envelope issues, prevented the business from fully functioning. The cost to a single business can be more catastrophic than the physical storm damage.
The storm-hardening evaluation and facility hardening should be considered by any business or organization, especially those which provide services to the public such as government facilities, hospitals, supply chain providers, food and grocery services, and any business that wishes to reduce loss following a storm event.
The WGI Structural Systems Division has provided Town of Palm Beach, City of Delray Beach, City of Boca Raton, City of Lake Worth, and Palm Beach County hurricane hardening assessments and American Red Cross evacuation shelter selection and evaluation (ARC 4496).
(After) WGI installed “K” bracing to stiffen the structural system.
The facilities evaluated for Palm Beach County, include PBC Sheriff headquarters, 22 public schools, 10 civic centers, eight buildings for Florida Atlantic University, and 188 structures and buildings for various water utilities.
Additionally, the WGI Structural Systems Division has numerous ongoing hardening projects for these same municipalities.
 From Wikipedia and “Hardening and Resiliency: U.S. Energy Industry Response to Recent Hurricane Seasons” (PDF). US Department of Energy. Retrieved 9 July 2013.