The shock of Sept. 11, 2001 brought a heightened focus to building safety and spawned new security measures at high-profile locations such as the Bank of America Tower in midtown Manhattan. Setbacks from the street, stricter access control and shatter-resistant glass are now common in corporate construction, says New York architect and security expert Barbara A. Nadel. -- Dan Levy
Photographer: David Sundberg for Bloomberg

The shock of Sept. 11, 2001 brought a heightened focus to building safety and spawned new security measures at high-profile locations such as the Bank of America Tower in midtown Manhattan. Setbacks from the street, stricter access control and shatter-resistant glass are now common in corporate construction, says New York architect and security expert Barbara A. Nadel. -- Dan Levy
Photographer: David Sundberg for Bloomberg

How September 11 Changed Architecture

Bank of America Tower, New York
Bank of America Tower, New York

The shock of Sept. 11, 2001 brought a heightened focus to building safety and spawned new security measures at high-profile locations such as the Bank of America Tower in midtown Manhattan. Setbacks from the street, stricter access control and shatter-resistant glass are now common in corporate construction, says New York architect and security expert Barbara A. Nadel. -- Dan Levy
Photographer: David Sundberg for Bloomberg

Bank of America Tower, New York
Bank of America Tower, New York

The 55-story high-rise on Manhattan's Sixth Avenue and 42nd Street, which opened in May 2010, also uses bollards at street level to deter car-bomb attacks. Perimeter protection is a crucial first line of defense, says Nadel.
Photographer: David Sundberg for Bloomberg

Bank of America Tower, New York
Bank of America Tower, New York

Shatter-resistant glass on the tower's massive curtain wall is intended to minimize flying shards in a blast, a main cause of post-attack collateral deaths.
Photographer: David Sundberg for Bloomberg

Bank of America Tower, New York
Bank of America Tower, New York

Like many companies, Bank of America is reticent about discussing security measures in the 2.1 million-square-foot building, which was designed by Cook + Fox Architects. Instead, the bank prefers to tout the tower's platinum certification for green construction and sustainability.
Photographer: David Sundberg/ESTO

7 World Trade Center, New York
7 World Trade Center, New York

The building, on the edge of Ground Zero in lower Manhattan, has a two-foot thick concrete core, redundant steel superstructure, and enhanced fireproofing and sprinkler capacity. The safety system exceeds New York City's building code, says developer Silverstein Properties Inc.
Photographer: David Sundberg/ESTO

7 World Trade Center, New York
7 World Trade Center, New York

The 52-story tower at Ground Zero opened in 2006 to replace the 47-story building of the same name that caught fire from burning debris in the World Trade Center attacks and then collapsed.
Photographer: David Sundberg for Bloomberg

7 World Trade Center, New York
7 World Trade Center, New York

 The plaza outside the 1.7 million-square-foot building, designed by Skidmore, Owings & Merrill, has elevation changes and low-rise obstacles to deter bomb-laden vehicles.
Photographer: David Sundberg for Bloomberg

New York Stock Exchange
New York Stock Exchange

Seven city blocks in New York's financial district, including iconic sections of Wall, Broad and Exchange streets were fortified by more than 70 bronze bollards, designed by Rogers Marvel Architects of New York and installed beginning in 2003. Their hardened steel and concrete cores are an example of redundancy in security design.
Photographer: David Sundberg for Bloomberg

New York Stock Exchange
New York Stock Exchange

Rogers Marvel designed the bollards with angled forms to pick up light at different points in the day and serve as lunchtime seating and meeting spots. "The chance they will be used for their intended purpose is statistically small,'' says firm principal Rob Rogers. "But since they are a part of the public realm, we hoped to create something that was a delightful part of city life.''
Photographer: David Sundberg for Bloomberg

Battery Park City, New York
Battery Park City, New York

"Tiger Trap" collapsible sidewalks have been installed in Battery Park City and are modeled on airport runways that are engineered to crumble and slow a hurtling plane, the technology is also being proposed for the Pentagon's enhanced perimeter plan, Rogers says.

Battery Park City, New York
Battery Park City, New York

Glass benches installed elsewhere on Battery Park City's waterfront serve a dual purpose as functional urban furniture and obstacles for vehicle attacks. Security can be "ridiculously robust but elegant,'' Rogers says.

U.S. Embassy, Berlin
U.S. Embassy, Berlin

A 1995 competition for a new embassy near Berlin's Brandenburg Gate was won by architects Moore Ruble Yudell of Santa Monica, California. Three years later, terror bombings at U.S. embassies in Kenya and Tanzania halted the plans. More delays ensued over a revised design that would have enclosed the property in a security zone cut off from Pariser Platz. In order to accommodate U.S. security requirements, city authorities moved the adjacent street farther away from the building. The complex finally opened in 2008.
Photographer: Sean Gallup/Getty Images

U.S. Embassy, Beijing
U.S. Embassy, Beijing

The Beijing embassy was also completed in 2008. This time, distance from the surrounding environment wasn't seen as a problem. SOM architects said it was honoring Chinese design by employing large pools, courtyards and a decentralized building plan over 10 acres in the spacious capital city. Rendering: courtesy of the Embassy of the United States

Federal Building, San Francisco
Federal Building, San Francisco

The San Francisco Federal Building, completed in 2007 and designed by Morphosis Architects of Santa Monica, shows in bold relief the U.S. General Services Administration's Sept. 11 security requirements:  a plaza well set back from the street and potential truck bombs and blast-resistant exterior materials including glass. A spacious lobby allows for screening machines and queuing.
Photographer: David Paul Morris/Bloomberg