Future buildings—especially tall structures—should be increasingly resistant to fire, more easily evacuated in emergencies, and safer overall thanks to 23 major and far-reaching building and fire code changes approved recently by the International Code Council (ICC) based on recommendations from the Commerce Department's National Institute of Standards and Technology (NIST).
The recommendations were part of NIST's investigation of the collapses of New York City's World Trade Center (WTC) towers on Sept. 11, 2001. The changes, adopted at the ICC hearings held Sept. 15-21, 2008, in Minneapolis, Minn., will be incorporated into the 2009 edition of the ICC's I-Codes (specifically the International Building Code, or IBC, and the International Fire Code, or IFC), a state-of-the-art model code used as the basis for building and fire regulations promulgated and enforced by U.S. state and local jurisdictions. Those jurisdictions have the option of incorporating some or all of the code's provisions but generally adopt most provisions.
The new codes address areas such as increasing structural resistance to building collapse from fire and other incidents; requiring a third exit stairway for tall buildings; increasing the width of all stairways by 50 percent in new high-rises; strengthening criteria for the bonding, proper installation and inspection of sprayed fire-resistive materials (commonly known as "fireproofing"); improving the reliability of active fire protection systems (such as automatic sprinklers); requiring a new class of robust elevators for access by emergency responders in lieu of an additional stairway; making exit path markings more prevalent and more visible; and ensuring effective coverage throughout a building for emergency responder radio communications.
Nine additional code change proposals based on the NIST WTC recommendations were not approved for the 2009 edition of the I-Codes.
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).
Changes to U.S. Model Building and Fire Codes
The following are the 23 model building and fire code changes consistent with the NIST WTC investigation recommendations now required by the I-Codes (changes displayed in italics are ones that were approved at previous ICC hearings and incorporated at the Minneapolis hearing into the 2009 I-Codes):
Field installation requirements for fireproofing to ensure that:
Special field inspections of fireproofing to ensure that its as-installed thickness, density and bond strength meet specified requirements and that a bonding agent is applied when the bond strength is less than required due to the effect of a primed, painted or encapsulated steel surface. The inspections are to be performed after the rough installation of mechanical, electrical, plumbing, sprinkler and ceiling systems.
Luminous markings delineating the exit path (including vertical exit enclosures and passageways) in buildings more than 75 feet high to facilitate rapid egress and full building evacuation.
Broadening the use of luminous markings to identify obstacles, exit doors, exit signs and floor numbers in the exit path in buildings more than 75 feet high.
Luminous exit path markings in existing buildings more than 75 feet high with the exception of open, unenclosed stairs in historic buildings.
Increasing the area of the Fire Command Center (the area from which all fire department operations are directed and usually housing the control panel for alarms, sprinklers, etc.) from 96 square feet to 200 square feet with at least one side 10 feet long in buildings more than 75 feet high.
Approved radio coverage for all buildings for emergency responders within the building based upon the existing coverage level of public safety communications systems at the exterior of the building. Approved coverage includes specific requirements for signal strength, system design, installation and maintenance.
Installing an emergency responder radio communications system to provide the required level of radio coverage throughout a building. Typical hardwired communications systems would be replaced.
Additional Proposed Changes to U.S. Model Building and Fire Codes
The following are the nine model building and fire code change proposals consistent with the NIST WTC investigation recommendations that were not approved for the 2009 edition of the I-Codes but will be considered for resubmission at a later date after being amended:
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Materials provided by National Institute of Standards and Technology. Note: Content may be edited for style and length.
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