The international architectural design competition for the high-rise complex on what is called the Millennium Area in Frankfurt has been decided. The jury, chaired by architect Prof Johann Eisele, chose the design by the Frankfurt architectural firm Ferdinand Heide as the winner of the competition. Second place went to the architectural firm Cobe from Copenhagen. The offices of David Chipperfield Architects (Berlin/London) and Schneider + Schumacher Architekten (Frankfurt) also received commendations.

The now-completed architectural design competition has created the basis for the further development of what is called the Millennium Area (in German: Millennium Areal). CA Immo and the City of Frankfurt had developed the concept for a mixed-use building complex with two high-rise buildings of different heights and block pe-rimeter development. While the block perimeter building and the lower high-rise (Tower B) are to be predominantly residential, a mixture of office and possibly hotel use is currently planned for the higher high-rise (Tower A). In addition, public uses such as food services, retail, services and a day-care centre are to be accommodated in the ground floors and on the lower floors to create a lively and diverse complex of buildings.

The design by Ferdinand Heide envisages the construction of a 288-meter office and hotel tower (Tower A), a 157-meter residential tower (Tower B) and a block perimeter building in a wood hybrid construction. In terms of building law, the two high-rise buildings have a height of 280 meters (Tower A) and 150 meters (Tower B), which are, however, slightly higher due to the two sloping roofs. The two towers will be twisted in an intriguing way creating spacious terraces and attrac-tive projections and recesses in the building cubature, especially in Tower A. Through the “twist” in the towers, however, the design also succeeds in increasing the distances between the buildings, which is particularly beneficial for the lighting of the flats in Tower B and significantly increases the energy yield for photovoltaic systems integrated into the façade. On the ground floors, the design provides for public spaces with a high quality of stay.

The crowning glory of Tower A is the design of a publicly accessible “Sky Hall”, which can be used both as an event space and as a viewing platform.

Prof Johann Eisele, Chairman of the jury: “The design of Ferdinand Heide for the high-rise complex won over the jury with the successful urban disposition of the buildings, which also establish a relationship to the existing Tower 185. The design features a successful hierarchy of public spaces and a coherent identity for the various building parts and uses. It also has spectacular architecture: The tallest building is designed as a twisted sculpture. The upper end of this tower is concisely shaped and gives the building a striking, unmistakable impact at a distance.”

Mike Josef, Head of Planning for the City of Frankfurt, adds, “The competition process provided an excellent result that is convincing in terms of sustainability and mixed use – even in one of the tower peaks. The fact that 200 of the total number of around 500 apartments are publicly subsidized benefits the social mix of the entire neighbourhood. I am particularly pleased that an architect from Frankfurt, Ferdinand Heide, has won the race. His two high-rises will hopefully soon complement the high-rise cluster at the trade fair center in terms of urban development and enrich the skyline with their architectural appeal.”

In addition to outstanding architectural and urban development quality, CA Immo had already formulated the highest and most ambitious requirements in the competition announcement for both a re-source-saving and climate-friendly realisation and the future operation of the building complex. This includes an innovative energy concept through which a large part of the energy required by the buildings is to be regeneratively generated directly in or on the building, among other things through the use of large-scale photovoltaic systems in the facades of the high-rise buildings and through the storage and use of internal heat sources of the buildings. When it comes to the building materials to be used, it is important that the extraction and processing comply with recognised ecological and social standards. They should generate the lowest possible level of “grey energy,” require low operating costs for cleaning and maintenance, provide the longest possible service life and feature a high degree of deconstruction and recycling capability. CA Immo had already carried out extensive preliminary studies on all aspects of sustainability, the results of which were presented to the competition participants as objectives and concrete planning guidelines.

In his design, Ferdinand Heide showed convincing approaches to all these aspects. These include the architectural design concept of the perimeter block building in a wood hybrid construction and an in-novative structural concept for the high-rise buildings, which requires around 20 % less concrete and steel than conventional construction methods. The requirement to implement photovoltaic systems in the façade of the high-rise buildings was also solved in a way that was both highly energy-efficient and architecturally convincing. Some 3500 photovoltaic modules on the façade and roofs meet up to 25% of the buildings’ electricity needs. In addition, an energy concept was developed which, among other things, ensures highly efficient and resource-saving operation of the buildings through the use of geothermal energy and heat recovery.

Matthias Schmidt, Managing Director CA Immo Germany and Head of Project Development: “Our vision for the complex that was formulated for the competition was not simply to develop the tallest office building in Germany. We want to see a building here that both makes a statement architecturally and will be regarded as a new benchmark for sustainable building development in the future. Ferdinand Heide has mastered this task in an outstanding way, like no other office in the competition. We are convinced that this iconographic design does justice to the justifiably high design standards of this project. At the same time, Ferdinand Heide and the specialist planners have shown how innovative construction principles can be used to conserve precious raw materials, save the ‚grey’ energy bound up in the building and reduce the CO2 footprint already in the erection of the complex. The flexibility of the structure also ensures a long-term useful life. And CO2 emissions were also significantly re-duced for the operation of the building through the maximum use of renewable energies. For example, both the use of geothermal energy and the in-house production of electricity via extensive solar panels in the façade are planned for the building complex.”

Construction start will not likely be before 2025/2026. Specific timing has not yet been decided upon by CA Immo and will depend on a number of factors including, among others, receipt of building per-mission, decision on ultimate usage mix, and satisfactory market demand resp. pre-leasing ratios.”

Eight renowned international, national and local architectural firms were invited to participate in the architecture competition. These include the firms 3XN Architects (Copenhagen), David Chipperfield Architects (London/Berlin), Cobe (Nodhaven), Ferdinand Heide Architekt (Frankfurt), Herzog & de Meuron, (Basel), Ingenhoven Architects (Düsseldorf), OMA (Rotterdam), Schneider + Schumacher Architekten (Frankfurt).

The competition results of all participating offices as well as the revised winning design by Ferdinand Heide will be publicly exhibited from 6th to 17th December 2021 in the atrium of the Frankfurt City Planning Office.