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Buildings
New
York's Building Code Reflects High-Rise Concerns
Recommendations
from 9/11 will be debated
(enr.construction.com - 05/31/04 issue)
By Barbara
A. Nadel
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| 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 Citys
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.
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.
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Source: Building
Security: Handbook for Architectural Planning and Design,
By Barbara A. Nadel, McGraw-Hill (2004).
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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 wont 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 Yorks 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...
(continued...)
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