Steps to Disaster Resilience

There are essentially two ways to approach disaster mitigation. There are voluntary programs where communities or building owners voluntarily reduce their risk of natural disaster through enhancements in structures, warning systems, and education. The second approach is to install mandatory building requirements such that communities and building owners are obligated to design buildings and infrastructure to be more disaster resilient. The following are steps, combining both voluntary and mandatory mitigation strategies, to achieving disaster resilience:

1. Adopt updated building codes.
2. Adopt high-performance building standards.
3. Incentivize disaster resilient construction.
4. Build with robust materials.

1. Adopt Updated Building Codes

A common misconception is that a new code-compliant building in the United States will be resilient against considerable damage after a major hazard event. This is not always the case. The building code sets standards that guide design and construction of structures for minimum life safety, the first step toward resilience. However, maintaining the functionality of structures after a disaster is also important, and building codes do not address functionality effectively. Sadly, special interests have convinced some state legislatures to reduce the stringency or limit the adoption of the latest building code.

According to the International Code Council (ICC), Alaska, Arkansas, Indiana, Tennessee, and Texas have statewide building codes from 2012 or earlier, and Arizona, Colorado, Delaware, Illinois, Kansas, Missouri, and Nevada still do not have a statewide building code but pass the responsibility to local jurisdictions. Florida, the state that faces more hurricanes than any other, decided in 2017 to weaken its code-adoption process. The North Carolina state legislature decided to placate homebuilders and update the building code only once every six years instead of every three. Builders claimed that weaker codes makes it easier and cheaper to build in North Carolina, but new homes were ill-prepared for Hurricane Florence’s high winds, storm surge, and rainfall. These states are not alone. Unchecked development remains a priority for powerful lobbyists, creating short-term economic gains for some while increasing risks for everyone else. As a result, the American taxpayers are footing the bill for disaster relief.

If we are to take people’s vulnerability seriously, we must deploy—and insist on—much greater emphasis in mandatory code adoption. While the design community can provide some of the expertise, its voice is not being effectively considered on the planning and policy level. The missing element is participation among practitioners, the development community, and policymakers interested in public safety over economic opportunism.

2. Adopt High-Performance Building Standards

Buildings should not be a burden on their communities. They should have sufficient functionality after a hazard event and not place excessive demand on community resources such as emergency responders, including fire, police, and hospitals. Communities with disaster-resilient buildings are more likely to be able to operate schools and businesses after a disaster. Stronger homes and buildings mean people will have places to live and work after a disaster. Less disruption for a community means robust commerce and consistent tax revenue.

Resilient buildings should consider a higher level of performance to protect property. Property protection means the building can withstand impacts and continue to provide its primary functions after a major disruptive event. The following are programs and standards aimed at incorporating resilient building techniques into construction to provide an optimum level of protection against a variety of natural hazards.

Enhanced Building Codes

Enhanced building codes can be developed and adopted through the building code appendices. The appendices are provided in the International Building Code (IBC) and the International Residential Code (IRC) to offer supplemental criteria to the provisions in the main chapters of the code.

After damaging windstorms in 2008, the Georgia Department of Community Affairs created the Disaster Resilient Building Construction (DRBC) appendices to the IBC and IRC, which form the basis for the Georgia State Building Code. The DRBC appendices offer an affordable, flexible, and simplified approach to improving resiliency at the local level. Local jurisdictions can adopt the complete appendices to improve building resiliency against flooding and high winds, or they can adopt select sections that apply to specific hazards in their geographic areas.

Floods are the most frequent hazard resulting in disaster declarations. For those jurisdictions seeking to enhance their local floodplain management regulations, a compilation of flood-resistant provisions is provided in Appendix G of the IBC. Like the Georgia DRBC appendices, the provisions contained in Appendix G are not mandatory unless specifically referenced in the adopting ordinance. The appendix helps minimize the expenditure of public money in many ways, including flood-control projects, the need for rescue and relief efforts, prolonged business interruption, damage to structures, and ultimately protecting human life.

FORTIFIED Programs

The FORTIFIED Home and FORTIFIED Commercial programs of the Insurance Institute for Business and Home Safety (IBHS). The program provides enhanced design criteria relative to code minimum and the necessary construction and inspection oversight to ensure high-performing structures that are truly disaster resilient. The IBHS is a not-for-profit applied research and communications organization supported by the insurance industry.

USRC Building Rating System

The U.S. Resiliency Council (USRC) is a national organization dedicated to improving the sustainability and resiliency of buildings during earthquakes and other natural hazards. The performance-based USRC Building Rating System assigns one to five stars along the dimensions of safety, damage expressed as repair cost, and recovery expressed as time to regain basic function. Certified buildings are expected to perform in a manner that will preserve the life safety of the occupants, limit damage to repairable levels, and allow functional recovery within a reasonable time period after a major seismic event.

REDi Rating System

The Resilience-Based Earthquake Design Initiative (REDi) Rating System is a set of specific design performance criteria that aims to minimize building damage and promote contingency planning for utility disruption and other threats to functional recovery. The success of the resulting design in meeting specific monetary loss and recovery time is demonstrated by performing a modified FEMA P-58 loss assessment developed specifically for REDi.

RELi Standard

The RELi standard is a point-based system recently adopted by the U.S. Green Building Council (USGBC). It includes many LEED-centric credits along with risk mitigation credits at the building and neighborhood scale. The intent is to provide greater adaptability and resilience to weather and other natural hazards in the built environment as a complement to LEED. USGBC is currently refining RELi to provide a comprehensive list of resilient design criteria.

Photo: John Swain Photography/Clark Pacific

Figure 4: Roseville City Hall Annex in California was the first building to achieve USRC Platinum certification.

Case Study: Earthquakes
Roseville City Hall Annex, Roseville, California

The 4-story, 82,000-square-foot Roseville City Hall Annex office building houses critical city services, such as IT, public safety communications, and fire administration. Integrated project delivery (IPD) methods were employed to meet a short timetable for occupancy. Utilizing a precast hybrid moment frame (PHMF) gave the architect flexibility in the design and helped to meet a tight construction schedule. The concrete structure was erected in just 38 days, which provided plenty of time to finish the project in seven months. Also important for the City of Roseville, California, was reassurance that critical operations and services would continue during an earthquake.

This project is the first to be rated and accredited by the U.S. Resiliency Council (USRC), achieving Platinum level certification. The structural system incorporates a high-performance moment-resisting frame that limits design level drifts to less than 1.25 percent. The system is designed to be self-centering after the seismic event, eliminating residual drifts, limiting damage, and providing for reduced recovery time. Other added benefits from an operational perspective include lower long-term maintenance costs, superior sound isolation/exterior noise suppression, and approximately 30 percent less energy consumption because of the building’s thermal mass.