Based on recommendations from the National Institute of Standards and Technology (NIST) arising from its WTC investigations, the ICC membership adopted 23 code change proposals addressing areas such as increasing structural resistance to building collapse from fire and other incidents; requiring a third exit stairway for tall buildings and 50 percent increase in stairway width; providing for a heavy-duty class of elevators to be used by emergency responders in lieu of an additional stairway; and strengthening criteria for the bonding, installation and inspection of sprayed fireproofing, among others. The changes were adopted at ICC hearings held Sept. 15-21, 2008, in Minneapolis, MN, and will be incorporated into the 2009 edition of the ICC’s I-Codes. New York, both city and state, along with other jurisdictions which may choose to adopt the 2009 edition, will still have the option of incorporating or deleting some or all of these provisions.
Nine additional code change proposals based on the NIST WTC recommendations were not approved. These proposals address areas such as designing structures to mitigate disproportionate progressive collapse, mandating the use of a nationally accepted standard for conducting wind tunnel tests (routinely used for determining wind loads in the design of tall buildings), limiting the length of horizontal transfer corridors in stairways, installing stairway communication and monitoring systems on specific floors of tall buildings, and requiring risk assessments for buildings with substantial hazard (such as buildings more than 420 feet high with occupant loads exceeding 5,000 persons).
Summaries of the approved changes and unapproved proposals, may be found at http://wtc.nist.gov.