Two years ago, the Freedom Tower planned for the World Trade Center site represented the best thinking in tall building design. The version developed in 2003 by architect David Childs and engineer Guy Nordenson employed an exposed diagonal “diagrid” structure to distribute both vertical and lateral loads, including the potential pressure of a bomb blast, around the building perimeter and over buried train tracks. This system would have reduced the likelihood of collapse in a catastrophe while also giving the building a distinctive beauty. The tower’s torquing shape likewise combined functional and aesthetic advantages: In addition to minimizing wind turbulence, it would have created a constantly changing silhouette. A lofty cable structure was engineered to support wind turbines generating some of the energy consumed by office floors below.
Those features are gone now. Over the past two years, the tower has gradually been stripped of its best attributes. The final blow was delivered earlier this summer by the New York Police Department, which forced a total redesign when it demanded a greater setback from the street and a heavy barricade to resist potential bombs. Now, just after the fourth anniversary of 9/11, the Freedom Tower has become a bland prism with a forbidding 200-foot-high concrete base.
The new design is no good because it reflects the wrong approach to counter terrorism. In the name of defending the tower against a bomb blast, developer Larry Silverstein, Governor George Pataki, and the NYPD have induced Childs and engineers Cantor Seinuk (Nordenson left over design changes) to eliminate features vital to the long-term security of our open society. Instead of fortresses that rise from bunkers in empty plazas, we need buildings that promote urban interaction, sustainable energy policies, and the lively commerce in goods and ideas that has long been our greatest strength. Securing ourselves against terrorism includes making sure that misguided counterterrorist policies don’t stifle our creativity and depress our economy. It is as much a matter of good urbanism, energy efficiency, and compelling design as it is of setbacks and barricades.
How do these factors bear on security? In addition to safeguarding against the immediate threat of a terrorist bomb, new buildings need to enhance our society’s long-term viability. Excessive reliance on nonrenewable fuel reduces our environmental quality and economic strength. It also distorts our foreign policy, leading us to support states where oil production funds repressive regimes that inspire terrorists, as happened in Saudi Arabia with Al Qaeda. Nor is the aesthetic power of good architecture beside the point in the global competition for “hearts and minds” between democracies and authoritarian or fundamentalist regimes. Great buildings, like business innovations or a vibrant culture, demonstrate a society’s vitality. If we want to increase our long-term resilience, we should adopt design strategies that not only resist bomb blasts but also promote openness, exchange, conservation, and innovation.
New York can learn from its closest counterpart across the Atlantic. Long a target of Irish Republican Army bombings, London has a track record of integrating security concerns into its architecture and planning, and it has recognized the value of sustainable design. A central London office building recently completed by Norman Foster, Britain’s leading architect, shows just how good progressive security design can be. That the building in question houses Swiss Re, the primary insurer paying for the World Trade Center reconstruction, and replaces a structure damaged in a 1992 IRA bombing, only increases its relevance.
Dubbed the Gherkin, the 41-story Swiss Re building has a tapering cylindrical profile like that of a torpedo. This unique shape is optimized to reduce wind turbulence at street level and naturally ventilate the interior through six atriums that spiral through the building, drawing in fresh air and venting office areas. In addition to providing workers with daylight and striking views, these atriums allow the building to employ natural ventilation for about 40 percent of the year, lowering the building’s energy consumption an anticipated 14 percent below even stringent low-energy standards. What’s more, these aesthetic, experiential, and environmental advantages don’t come at the expense of security. A diagrid structure like that formerly planned for the Freedom Tower gives the building the strength to withstand a bomb blast, and a carefully designed plaza provides a setback while sensitively reinforcing the pedestrian urbanism of London’s financial district. The Swiss Re building is a virtuoso synthesis of security provisions with features that reduce energy consumption, stimulate workers, and enhance the cityscape.
Those in charge of rebuilding lower Manhattan missed an opportunity for Foster to replicate his Swiss Re success here when they passed over his entry in the competition that led to the Freedom Tower design. By allowing a one-dimensional idea of security to trump pedestrian urbanism, energy efficiency, and aesthetic power, they have now let us down again. Fortifying individual buildings won’t do much good if it comes at the expense of the underlying ecologies that sustain our open society. But we shouldn’t have to choose between short-term protection and long-term security when we can have both. If we follow the lead of Foster and Swiss Re, securing our buildings against bombs can also lead us toward the social and economic renewal that is ultimately our best defense against the terrorist threat.