| “This was going to be a long-term project that was really huge in terms of the impact.” | |
| Ann Ogata-Deal, Hawaii Coastal Zone Management Program | |
Hawaii’s famously lush green mountains, coastal cliffs, and valley gorges make it one of the most visually dramatic places in the world. It is this very terrain that led state coastal resource managers to help launch a community resilience initiative that resulted in statewide adoption of hurricane-force-wind building-design standards that are specific to each of Hawaii’s four counties.
“There was a great need for this project because of the landforms in Hawaii,” says Ann Ogata-Deal, planning and policy analyst for the Hawaii Coastal Zone Management Program. “We have huge volcanoes that cause wind speeds to differ significantly in various parts of the islands.”
Research specific to Hawaii’s wind hazards was needed to ensure that the design standards in the International Building Code being adopted by the state would be correct for Hawaii’s wind conditions.
“What we created are different design criteria that depend on where a building is proposed to be built,” says Russ Saito, Hawaii state comptroller and chair of the State Building Code Council. “From now on, all new construction [in the state] will be subject to more rigorous standards.”
“This effort was scientifically driven,” adds Gary Chock, president of the engineering firm Martin and Chock, Inc. “This is a good example of science informing policy.”
Consistently Inconsistent
Until recently, Hawaii’s four counties were following either the 1991 or 1997 Uniform Building Codes.
“Basically, we had four counties establishing their own codes,” explains Saito. “There wasn’t any consistency among the counties—or the state—which has overriding responsibility for the construction of state facilities.”
The result was a system of fragmented building requirements that was causing problems for contractors, building designers, and the insurance industry.
Following Recommendations
Since 1992, the Structural Engineers Association of Hawaii has recommended that specific wind studies be done for Hawaii’s unique topography and that the study results be considered in new building codes, says Chock. In 2000, work began in the state to develop a statistically valid method for predicting wind speeds based on various topographic parameters.
In 2005, conducting island-specific wind speed studies became a priority for the Hawaii coastal program and its network of partners working on coastal hazard mitigation, says Ogata-Deal.
“We realized early on that we could step in and make a difference,” she says. “This was going to be a long-term project that was really huge in terms of the impact, as well as in the funding it would take to get the job done.”
The coastal program used federal 309 coastal zone enhancement grant monies to fund wind speed research for the counties of Maui and Hawaii using techniques that would account for wind flow over the terrain. The Federal Emergency Management Agency funded the work for Oahu and Kauai.
The studies included “what the formula should be in determining proper design in very specific areas of each island,” Ogata-Deal says.
“All new structures will have exactly the same level of risk,” notes Chock. “That is the essential elegance of this methodology.”
Adopting Standards
In 2007, while the wind research was underway, the Hawaii legislature stepped in and directed the creation of a State Building Code Council, which would lead the adoption of the international and other codes for statewide application.
“Their job,” says Ogata-Deal, “was to establish a comprehensive state building code. The law specifies that standards be included for natural hazards such as hurricanes, flood, and tsunami.”
By mid-2008, the completed wind speed studies were provided to the State Building Code Council.
After a detailed review process, the council unanimously adopted the wind standards for all four counties, including them as a technical amendment to the 2006 International Building Code being adopted by the state. At the time this article was written, the new state building code incorporating the wind standards was waiting to be signed into law by the governor.
The new state code “requires the counties to amend and adopt the state building code for their own use,” explains Saito. “If they don’t do so in two years, then the state building code becomes the county code.” All new construction of state facilities must adhere to the new building codes within a year.
Two counties—Honolulu and Kauai—are already using the new codes.
Learning Curve
The new codes are “quite a change from what we had before,” says Ogata-Deal. “The codes themselves incorporate more state-of-the-art engineering and hazard mitigation standards. There’s quite a large learning curve for all of those involved in code implementation.”
To help with this learning curve, the coastal program is providing funding for training on implementing various aspects of the code. So far, diverse training courses have been administered to about 1,800 county, state, and federal building officials, design professionals, and development, building, and insurance industry representatives.
National Recognition
The work Hawaii has done developing and incorporating the island-specific-wind building-design standards isn’t going unnoticed.
The American Society of Civil Engineers Standard for Minimum Design Loads designated the State of Hawaii as a special wind region, which codified national acceptance of the technical applicability of the state’s topographic wind speed adjustments.
The coastal program was also recently honored by the Hawaii Chapter of the Construction Specifications Institute, a professional industry organization, for providing the training on the new state code.
“The approach we used is applicable anywhere,” Saito says. “It really makes a lot of sense to do [area-specific] seismic zoning and wind speed maps.”
“This is the project with the most lasting effect of any that I’ve worked on,” says Ogata-Deal. “We focus on reducing the risk to life and property in our coastal hazards work. This will actually do that statewide, and will benefit everyone in Hawaii in one way or another.”
For more information on Hawaii’s new wind-specific building codes, contact Ann Ogata-Deal at (808) 587-2804, or AOgata-Deal@dbedt.hawaii.gov, or Russ Saito at (808) 586-0400, or russ.k.saito@hawaii.gov. For more information on the science and engineering work, contact Gary Chock at (808) 521-4513, or gchock@martinchock.com.
