The National Storm Shelter Association (NSSA) grew out of a concern for tornado shelter quality after the Oklahoma City tornadoes of May 1999. Concept of the above ground tornado shelter, called an in-residence shelter, had been introduced in the Civil Engineer Magazine twenty five years earlier. Redevelopment of the shelter concept had reached the point where Federal Emergency Management Agency (FEMA) had published a booklet FEMA 320 entitled “Taking Shelter From the Storm-Building a Safe Room Inside Your House or Small Business”.
State of Oklahoma decided to use substantial mitigation funding made available by FEMA to supplement the construction of tornado shelter in Oklahoma. This incentive program created an unprecedented demand for shelters within a short period of time. Home builders responded to the created market for tornado shelters, building primarily those shelters featured in FEMA 320. For these shelters, building inspectors were charged with ascertaining compliance with FEMA 320. Manufacturers also responded to the market for above ground shelters by creating an exciting array of manufactured shelters or kits to be assembled into tornado shelters. Since no specifications were available, it was required that shelters be tested for debris impact resistance and that they have an engineer’s seal.
As one might expect in any new industry, many quality issues surfaced. Few engineers were both qualified and willing to design tornado shelters to verify quality of existing designs. There was no standard available for shelters not shown in FEMA 320. Those performing debris impact tests, as well as the manufacturers of quality products, became painfully aware of quality problems within the newly founded industry. Within the first year after the Oklahoma City disaster, more than 20 companies had their manufactured shelters tested at Texas Tech University for debris impact resistance. TTU professor Dr. Ernst Kiesling invited those companies to a meeting at the University in February of 2000 to address issues of quality in the storm shelter industry. The National Storm Shelter Association was conceived, and Lubbock, Texas was designated as its headquarters.
The purpose of the National Storm Shelter Association is to foster quality by recognizing and distinguishing the shelter producers and products who meet a high standard of quality. They are entitled to affix a seal to their shelters testing compliance with applicable standards. But in the beginning there was no standard! Hence, the first major undertaking of the NSSA was to develop an industry standard. Almost a year was consumed in evolving the first draft of an industry standard for tornado shelters.
Criteria for Producer Member grade in the NSSA requires that shelter producers-builders or manufacturers-comply with FEMA 320 for site-built tornado shelters or that they have their shelters tested for debris impact at a NSSA approved facility and that they have their designs and engineering calculations verified by a third party engineering company to be in compliance with the standard. For a variety of reasons, few shelter producers have “gone the distance” to meet the requirements for membership in NSSA. Nevertheless, code development continued within NSSA with the intent of evolving the industry standard into a national consensus standard. Fortunately, in July of 2002 an agreement was reached between the International Code Council (ICC) and the National Storm Shelter Association (NSSA) to develop a national consensus standard to be accredited by the American National Standards Institute (ANSI). ICC-500 is the ICC/NSSA Standard for Design and Construction of Tornado Shelters completed in 2008 and is available for adoption by code jurisdictions. An update to the 2008 edition of ICC-500 may be expected by 2013. ICC-500 may be purchased from the International Code Council or from the National Storm Shelter Association.
Outline of Major Milestones
Wind Engineering Beginnings Research into improving buildings for resisting extreme winds began with the 1970 Lubbock tornado. Twenty-six people were killed and about 1/3 of the city of 160,000 people was heavily damaged or destroyed. Texas Tech researchers produced a comprehensive documentary of building damage, the first of its kind. The Wind Science and Engineering Research Center (WiSE) was developed and now after more than 40 years of research and education on the impact of wind on structures and human life and to better support the interdisciplinary research and educational opportunities in wind science, engineering and energy, TTU created the NWI (National Wind Institute-2012). The institute combines the former Wind Science and Engineering (WiSE) Research Center and the Texas Wind Energy Institute (TWEI) into one entity to support the overall wind enterprise at Texas Tech University. Concept of Shelter Idea The concept of the aboveground tornado shelter was presented in Civil Engineering magazine in 1974 by Texas Tech faculty member Dr. Ernst Kiesling and by Graduate Student David Goolsby. Intermittent development continued as available personnel and funding permitted.
Jarell, Tx Tornado, 1997 The total devastation of a small subdivision outside of Jarrell, TX received national attention and news coverage. Dateline NBC aired a special program covering the devastation and featured the aboveground storm shelter developed at Texas Tech University. Many regional and local television companies and newspapers subsequently featured the aboveground tornado shelter concept after severe storms struck in their areas.
Publication of FEMA 320 Personnel of the Federal Emergency Management Agency (FEMA) observed the high level of interest in tornado shelters among the public and published a prescriptive design booklet entitled, Taking Shelter from the Storm. The First Edition was published in October 1998, the Second Edition in August 1999. To date 200,000 copies have been printed and most of them have been distributed. The booklet, a copy of which is enclosed, is a prescriptive guidebook for design of small residential shelters.
Oklahoma City Area Tornados, May 1999 The widespread devastation of the Oklahoma City area tornadoes received widespread coverage in the media. An above ground tornado shelter survived the F5 tornado and also received widespread publicity. FEMA and the State of Oklahoma put in place incentives for building tornado shelters in houses that were being built or rebuilt after the tornado. Fortunately, the FEMA 320 publication was available to guide the design and construction of aboveground tornado shelters. It did not cover underground shelters. Because of the lack of standards and familiarity with the key elements of design, many quality problems were observed.
Organization of NSSA Criteria for approval of shelter incentive grants in Oklahoma for shelter designs not covered in FEMA 320 included debris impact testing. By the end of year 1999, more than 20 companies who manufacture above ground tornado shelters had had their products tested at Texas Tech University, the only laboratory designated by FEMA to conduct such tests. In February 2000, Dr. Ernst Kiesling invited these companies to a meeting at Texas Tech to address issues of quality in tornado shelters. The National Storm Shelter Association was conceived and Lubbock, Texas was designated as its headquarters.
Standards Development The National Storm Shelter Association held its first annual meeting in conjunction with the Oklahoma City Symposium in May 2000, on the first anniversary of the Oklahoma City area tornadoes. At that time, NSSA adopted a set of preliminary bylaws and elected its first Board of Directors. Mr. James Waller, P.E., was elected President. Committees were formed with specific charges. Work began in earnest on developing an industry standard of quality for tornado shelter design, construction, and installation.
Kiesling Appointed Executive Director During the Disaster Symposium and Exhibition in Tulsa, OK, May 2001, the Executive Committee of the Board of Directors of NSSA appointed Dr. Ernst Kiesling, a pioneer in shelter development, to serve as Executive Director of NSSA. Work continued in the evolution of the industry standard and in development of bylaws for the Association.
NSSA Standards Adopted by Board of Directors By a special meeting via the internet, the Directors adopted the NSSA Standard. It was viewed as an evolving document, to undergo periodic changes and eventually evolving into a national consensus standard.
Bylaws Adopted The revised bylaws including definition and administration of the seal program were adopted in January 2002.
Standards Development In May 2002, NSSA signed an agreement with the Southern Building Code Congress International, Inc. of the International Code Council to develop a national consensus standard for tornado shelters. The International Code Council/National Storm Shelter Association (ICC/NSSA) Standard for Design and Construction of Storm Shelters is accredited by the American National Standards Institute (ANSI). That standard was approved June 2008. Since then a second edition of the standard has been published (ICC/NSSA 500-2014) and in February 2016 the ICC/500-2014 Standard and Commentary was published. The ICC/NSSA Commentary provides a basic volume of knowledge as it pertains to the regulations set forth in the ICC/NSSA 500 2014. The commentary is to be used in conjunction with ICC/NSSA 2014 and not as a substitute for the standard itself. Either publication can be purchased through NSSA a a nominal price.
Texas Hazard Mitigation Grant Program Considerable mitigation funding became available to the State of Texas as a result of damage by Hurricane Rita in 2005. Funds were made available to several jurisdictions to rebate some construction costs of residential storm shelters and to partially fund construction of community shelters. The NSSA seal is required by some jurisdictions on residential shelters to qualify for the rebate. NSSA offers educational programs and other forms of assistance to participating communities to enhance shelter quality. Three courses on tornado shelter design may be found on the ICC website, www.ICCcampus.org. These courses were developed with funding assistance from the HMGP program. The project was administered by the Hazard Mitigation Division of the Texas Department of Community Affairs.
