United Architects, Ben van Berkel, Caroline Bos, Peter Frankfurt, Mikon van Gastel, Kevin Kennon, Greg Lynn, Farshid Moussavi, Alejandro Zaera-Polo, Jesse Reiser, Nanako Umemoto

This scheme for five linked towers was designed by a project-specific team of architects for the site of the former World Trade Center towers. The principal elements of each tower are a twenty-foot-square concrete core and two or more column-free volumes of habitable space that wrap around it. The supporting framework is a diagonally braced skin; its flexibility and strength allow the exterior tubes to expand and contract as they wrap around the core, producing the dynamic appearance of the ensemble. Each of the five towers is designed to be a self-supporting structure. Conjoined, they are able to resist tremendous forces through mutual support, and unlike a traditional freestanding vertical tower, they offer multiple routes of escape and firefighting access. A "sky park" creates a lofty horizon at the fifty-fifth floor, linking all the towers and bringing public access and social space to the highest common point of the five structures.
The project celebrates the tall building as a technical and cultural artifact. The towers soar to an awe-inspiring height and create a remarkable silhouette across the skyline, a symbol of collectivity; their gaps frame views, channel circulation, and create monumental urban spaces, including public space at street level.