FOUR, Frankfurt am Main

Architects:
UNStudio, Amsterdam/The Netherlands

Planning time
2017 – 2020

Construction time
2018 – 2022

Services by Werner Sobek
Structural engineering (SPH 1 – 8 in accordance with HOAI § 64) (in cooperation with Bollinger + Grohmann, Frankfurt am Main/Germany)
Structural analysis for demolition of existing buildings
Excavation wall engineering
Special structures – steel construction

Client
Groß & Partner, Frankfurt am Main/Germany

Images
UN Studio/Groß + Partner

FOUR, Frankfurt am Main/Germany

In March 2016 it was announced that the Dutch architectural firm UNStudio had won a concept competition for the urban redevelopment of Frankfurt’s DB estate with its plan to build four skyscrapers connected by a shared base structure. The winning design involves demolishing all but the historically listed buildings on Junghofstraße to make space for the development on the proposed site. According to the concept, the individual towers will stand at 228 metres (Tower 1), 173 meters (Tower 2), 120 metres (Tower 3) and 100 meters (Tower 4) in height. The largest of the towers – a 59-storey skyscraper located on Neue Schlesingergasse – will become the third-tallest structure in Frankfurt and serve as a hotel and office building. The shortest tower – situated on Junghofstraße – will also house offices. The remaining two high-rises will contain 600 apartments. The gross floor area of the buildings will amount to 210,000 m2 above ground and 100,000 m2 below ground. At least 90,000 m2 of this area will be dedicated to office space, around 60,000 m2 will be used for apartments, 30,000 m2 will house hotels and a further 20,000 m2 will accommodate retail outlets and eateries. After consultation with the city’s historic monument authorities, permission was granted for the creation of two openings in the long block of 1950s buildings on Junghofstraße to allow public access to the site for the very first time. The new six-storey base structure will contain shops, food outlets and a day care centre in a move to revitalise the area and transform it into a vibrant public space. The final architectural plans for the project were selected in February 2017 as part of a design contest that followed on from the concept competition of the previous year. UNStudio managed to build on its earlier success by winning the second competition as well, beating ten other competitors in the process. The construction site will be one of the largest ever seen in Frankfurt and provide employment for up to 3,000 people. The size of the overall investment is estimated at one billion euros. When complete, the new urban quarter will offer workspaces for 3,000 people and accommodation for a further 1,000.