DEFENSE Battery Park City used 3-D models to predict speed, impact conditions at perimeter. (IKONOS satellite image by Space Imaging)

A series of revisions to New York City’s building code, based partly on lessons learned from the 2001 attacks on the World Trade Center, are coming up for legislative and mayoral approval this summer.

"Building code officials have expanded the thinking for newand difficult situations, especially for those we are not equipped to research," says Patricia J. Lancaster, New York City Commissioner of Buildings. The National Institute of Standards and Technology, for instance, is analyzing stair enclosures, building hardening, new products and elevator enclosures without concrete or concrete block that could affect structural loads. New concepts are being developed, such as sheetrock with Lexan (a high-performance polycarbonate plastic) in the middle, and use of ceramic materials, not yet rated or tested.

Some New York Code Recommendations

Enhance robustness and resistance to progressive collapse. Prohibit use of open web bar trusses in new commercial high-rise construction. Encourage use of impact-resistant materials in stair and elevator shaft enclosures. Encourage more stairwells or wider stairwells in buildings. Prohibit use of scissors stairs in high-rise commercial buildings with floor plates over 10,000 sq ft. Require air intakes in new construction to be located at least 20 ft above grade and away from street loading bays.

Source: Building Security: Handbook for Architectural Planning and Design, By Barbara A. Nadel, McGraw-Hill (2004).

Without a single security code adressing design, facility operations and technology, owners and design professionals must rely on life safety and building codes, industry standards and federal guidelines for best practices. The National Council of Building Code Officials will use the New York City Building Code as a model and determine which items to adapt, making this effort a benchmark for other cities concerned about high-rise safety.

If proposed code recommendations prove to be too expensive, groups won’t advocate for them and their chances for adoption decrease, says Lancaster. Typically, 80% of the revisions are accepted, 15% are discussed in a mediation procedure or arbitration and 5% prove contentious enough to omit or arbitrate, she says. The proposed building code adresses operational concerns for owners and institutions.

The revisions are designed to create a more level playing field in competitive real estate markets and among varied building types because smaller buildings have the same concerns as larger ones. Developers and owners would have to provide a higher degree of building hardening and safety measures. New York’s consensus-driven code review includes a cross-section of the building industry, real estate property owners, government and Buildings Dept. officials and more than 400 professionals.

The operators of Battery Park City, a 92-acre mixed-use development located between the World Trade Center site and the Hudson River in Lower Manhattan that sustained substantial damage on 9/11, emphasized basic security when they began reconstruction efforts in 2001. The Hugh L. Carey Battery Park City Authority, the public-private operators, first increased perimeter security, landscaping and reviewed traffic patterns. As a high-profile site for financial and media tenants, design goals included transparent security, public amenities and maintaining onsite pedestrian access, while addressing vehicular bomb threats. Click here to view map

"We [first] wanted to eliminate Jersey barriers and planters, provide unobtrusive perimeter protection and urban design features to allow pedestrian movement," says Timothy S. Carey, BPCA president and CEO. "Bus shelters, bike racks and streetscape elements are engineered as bollards to restrict vehicular traffic. Boulders, trees and earth-backed walls as benches serve as vehicular threat deterrents." The U.S. Coast Guard determined the 70-ft waterfront plaza setback provides sufficient standoff in a river-based blast scenario, he adds. Harbor patrols, rather than new physical elements, offer additional surveillance.

"Battery Park City is implementing innovative security approaches merging technology and aesthetics," says Antony Woo, BPCA vice president for construction. Public-private teams are studying three-dimensional computer models for speed...