Web Exclusive! Performance Based Design--Local Needs to Global Needs
Around the world, prescriptive building codes and fire safety standards are increasingly being replaced or supplemented by performance-based standards that promise to provide increased design flexibility, lower costs, improved safety, and even enhanced global trade. In the U.S., performance-based design is slowly gaining a foothold. This article will attempt to provide an overview of the complex issues surrounding performance-based design and fire safety.
As you stand on the Brooklyn Bridge at dawn and look out on the city, the first light of day catches the Empire State Building, then the gleaming Chrysler Building. As the sun rises further, its rays lead your eye down the Boulevard, stopping at one architectural and cultural marvel after another. On your right stands a 36-story pyramid with a sphinx guarding the entrance. On your left, there's the Doges' Palace, the Rialto Bridge and St. Mark's Basilica. Across the street, the Eiffel Tower begins to glint above the Arc de Triomphe. The Eiffel Tower? Yes, you guessed it; this is Las Vegas, NV, a living monument to American fantasy, ingenuity and excess. It's also a prime example of performance-based design in action.
The unique world-unto-themselves hotel theme parks that make the Las Vegas Strip one of America's favorite vacation and gambling locations have all required performance-based design to some degree. Prescriptive codes alone cannot tell you how many exits it takes to make a restaurant safe on the 11th floor of a half-size Eiffel Tower replica.
While Las Vegas may overflow with performance-based designs, most areas of the United States still rely on building codes and fire safety standards that are prescriptive in nature. Unlike performance codes or guidelines that are based on design objectives and goals, prescriptive building codes tell you the exact requirements that must be met in order to make a structure safe for building occupants. This level of detail, while easy to enforce, also limits design, say critics. In addition, many of these prescriptive codes have been instituted on a regional basis across the U.S. in reaction to catastrophic fires, earthquakes and windstorms, resulting in a patchwork of standards.
Many are familiar with the common U.S. residential building standard that calls for wooden studs and beams to be located 16 inches-on-center. This is a simple example of a prescriptive code. In the United States, we do not yet have a single building code or set of unified standards that are used in every state. Building construction and fire safety design in the U.S. is primarily governed on a regional basis by four code models issued by nonprofit organizations. These include: