DESIGN CRITERIA AND LOADS
Robert E. Solomon
Chief Building Fire Protection Engineer
Building risk and hazard from the threat of fire have been largely managed through prescriptive code requirements since the 1800's. Use of fire resistive materials, compartmentation features, and later, installation of automatic sprinkler systems and automatic fire alarm systems have worked together to make tall buildings extremely safe from the effects of a fire. Code prescribed mandates have worked very well to direct architects and engineers towards the necessary level of protection for the building occupants as well as the structure itself.
In the United States, many code enforcement jurisdictions have recognized the effectiveness of these integrated systems. While any number of anecdotal stories or narratives can be used to demonstrate this, perhaps the most compelling argument lies in the evacuation strategies associated with tall buildings. In the majority of circumstances, tall buildings have become a "defend in place occupancy" when the appropriate prescriptive systems and design features are present. In these environments, occupants are normally best served and protected by remaining in a given area provided they are not in close proximity to the initial fire.
The US code system is now moving to incorporate performance design options as an alternative to the long established, time tested, prescriptive design that has dominated fire protection codes and standards for so many years. A performance code, as defined by NFPA is essentially a document that states its goals and provides reference to some, but not all, of the approved methods to achieve those goals.