The rebuilding of the World Trade Center site is one of the most important urban planning and architectural challenges of recent times. It is about memory, but equally it is about rebirth, demonstrating to the world the continuing strength and faith in the future that has traditionally shaped the New York skyline. Following the events of September 11th the practice commissioned an expert multidisciplinary team to conduct an in-depth study into safety in tall buildings. The lessons from that study informed this proposal, which celebrated New York's positive spirit with a unique twinned tower, designed to be the safest, the greenest and the tallest in the world.

The tower's crystalline form was based on triangular geometries - cross-cultural symbols of harmony, unity and strength. The two parts of the tower 'kissed' at three intervals over its 500-metre height, creating strategic links - escape routes in case of emergency - which corresponded with public levels containing observation decks, exhibition spaces and cafés. The tower was thus articulated vertically as village-like clusters, each with its own tree-filled atrium - effectively a 'park in the sky'. The building was naturally ventilated through its multi-layered, 'breathing' façade, and the atria played an environmental role, performing as its 'lungs', the trees oxygenating the circulating air.

In urban terms, the redevelopment was identified as a catalyst for the regeneration of the whole of Lower Manhattan, an opportunity to repair the street pattern that was eradicated in the 1960s and to bring new life to an area suffering economic decline. In place of a barren plaza, it envisaged green parks and streets on a human scale lined with shops, restaurants and bars. Connections further afield were strengthened by integrating the city's public transport networks in a new interchange below ground - a new gateway into Manhattan celebrated by a soaring glass canopy. The footprints of the destroyed World Trade Center towers were preserved as sanctuaries for remembrance and reflection. Gentle ramps led visitors down into an ambulatory lining an open volume where each tower once stood. Here, the city would be hidden from view, the sky above empty.

Development

Facts + Figures

  • Appointment: 2002
  • Area: 1,633,640m²
  • Height: 538m
  • Client: Lower Manhattan Development Corporation
  • Structural Engineer: Cantor Seinuk Group
  • Quantity Surveyor: Davis Langdon & Everest
  • Additional Consultants: Anish Kapoor, Roger Preston & Partners, Lerch Bates Associates Ltd, Space Syntax