The development of 400 Lake Shore Drive is located where the Chicago River flows into Lake Michigan, on the site where Spire, the 150-story Spanish architect, began construction in 2007, but halted the following year due to the global financial crisis .
The Spire land was signed by the developer Related Westwest in 2014. The company abandoned Calatrava's plan in favor of the proposal of the "skyscrapers brothers", for which he recruited Childs, designer of the One World Trade Center in New York, and to the architectural studio Skidmore Owings and Merrill (SOM).
While Calatrava's spiral tower was planned to include 1,300 luxury apartments, the new scheme for 400 Lake Shore Drive includes a combination of luxury condominiums, apartments and a boutique hotel in the two skyscrapers.
The pair will be placed at an angle to each other, with a large gap to the left to keep the views from downtown Chicago to the water. The duo has a different shape and size: the South Tower is thin and tall, while the shorter North Tower is more robust.
"We are proposing a new urban destination: two residential towers, iconic both at its base and in the sky, which differ in location, rotation and height," Childs said in a statement.
Staggered terracotta and glass facades form balconies for the residences and hotel rooms, and finally are reduced to the top to preserve the views. Additional details will be provided by metal frames around the windows.
The Childs design also pays tribute to the history of the Chicago School, a group of architects who developed a variety of projects in the city at the end of the 20th century. Among the main references is the choice of terracotta, which can be seen in Chicago landmarks, such as Wrigley Building, Reliance Building, The Sullivan Center and The Rookery, and rectangular windows formed in three parts.
The address of 400 Lake Shore Drive is also known as the former home of the city's founder, Jean-Baptiste Pointe DuSable.
With a height of 900 feet (274 meters) shorter than the Calatrava needle, the highest South Tower, 1,100 feet (335 meters), is located next to the Chicago River Walk, which the team plans to extend with a pass which goes under Lake Shore Drive. The addition would provide a direct link from the city center to the lake shore and the DuSable park.
Inside, the South Tower will have capacity for 300 of the condominiums and the 175-room hotel, as well as some of the amenities, while 550 apartments will be located in the 850-foot tall Torre (259 meters).
After the design of Calatrava was discarded, the global firm Gensler proposed another alternative for the site facing the sea, which was never collected. Similar to the Childs scheme, it contained a mixed-use program, with condominiums, rental apartments, two hotels, but also tourist attractions.
The Spire is not the first of Calatrava's projects to fail. Towards the end of last year, work in the Greek Orthodox Church on the site of the World Trade Center in New York was suspended indefinitely.
Some of his built works have also proved problematic: both the Oculus transport center in New York and the Ysios winery in Spain have emerged as leaks.
The city of Valencia also threatened to sue the architect after parts of the roof of the opera house in its City of Arts and Sciences complex began to fall, only eight years after its completion.
