Although building codes are written at the local municipality level, many cities turn for guidance to either the International Code Council (ICC) or the National Fire Protection Association (NFPA). The ICC's building code has been widely employed throughout the United States, while its newer NFPA counterpart is just getting its footing.
A New York mayoral commission consisting of industry, real estate, labor, and government leaders overwhelmingly chose to adopt and tailor the ICC code. The selection was based on 16 areas of comparison, such as code organization, performance history, ease of understanding, and adaptability to New York's situation. The ICC outscored the NFPA on each factor.
The ICC promulgates the International Building Code (IBC), one of many model construction codes that the organization has developed. The IBC establishes minimum regulations for the design and installation of building systems through prescriptive and performance-related measures. It addresses such issues as use and occupancy, safety, engineering practices, and construction technology. Through the IBC, the ICC will play a major role in determining how many more of the lessons from 9-11 are translated into changes to building codes--ultimately transforming new buildings--across the country.
The ICC has as yet generally not incorporated 9-11 lessons into the IBC. The group is waiting for the final NIST recommendations.
A draft of the NIST report is expected to be available this month. It will be finalized a few months later, after public comments are received and analyzed. At that point, ICC will look hard at adding post-9-11 provisions, says Mike Pfeiffer, vice president of codes and standards for the council.
In preparation, the ICC has established an ad hoc Terrorism-Resistant Buildings Committee. The committee comprises code officials, engineers, architects, and other interested building and security professionals.
A few code changes related to 9-11 were submitted in the 2003-2004 code-change cycle, Pfeiffer says. All but one was defeated, however, which may signal a tough road ahead for proponents of other changes.
The one code change that did get added to the IBC concerned fire-resistance ratings for buildings. It requires that the various components of buildings 420 feet and higher (about 42 floors including floor and roof construction) have a minimum three-hour structural fire-resistance rating, whether sprinklers are present or not. Previously, a building with sprinklers needed only a two-hour rating, explains Pfeiffer.
The rationale, according to an ICC statement, is that "fire department apparatus is generally not capable of supplying adequate water in terms of pressure and flow to floors located above 420 feet in height." Thus, these buildings "must be able to stand on their own."
Of the rejected proposals, one sought to widen stairs in buildings 20 stories and higher from 44 inches to 72 inches, Pfeiffer says. But there was no documentation to support the rationale for the 20-story threshold or the benefits of the specific increase in width, he says.
Another proposal would have required 25-story-and-higher buildings to encase stairwells in either concrete or masonry. Again, no specific data supported the change.
A final change would have set a standard for progressive collapse, which means that failure of one structural member leads to failure of another, and so on progressively. But it was "unclear what the expectation was," reports Pfeiffer, making it difficult to write a definitive provision.