In the last stage of the decade-long reconstruction of City-Nord Hamburg, Sauerbruch Hutton convinced the competition jury with their proposal for the former Postbank area. Of all the entries, this was the only one that proposed not to demolish the existing structure - a well-preserved, solid building constructed in the 1980s - but to recycle and adapt it as far as sensible and feasible. Approximately 40% of the existing building will be preserved and it will be extended with a new timber structure.

The campus that covers some 100,000 square metres of offices and residential areas, will also include a 16-storey residential tower of almost 50 m in height as well as a new office building. Following the motto ‘from fortress to quarter’, the existing structures will be opened up, decentralized and upgraded for various types of use. The restructuring of the existing courtyards will create a diverse urban fabric of public and semi-public spaces. The central courtyard serves as a meeting point and distributor with the residential tower as an iconic point de vue.

The conservation of the existing building as proposed in the competition results in an energy concept that is as sustainable as possible and that cannot be surpassed by a completely new structure. On account of the partial preservation of the building fabric, the savings are enormous and amount to 35 - 45 % compared to a new building with comparable floor area. The use of the CO2-neutral building material timber for the shell of the new residential tower and the additions to the existing buildings also contributes significantly to this ecological optimization.

Consequently, this design represents a prototype for careful urban redevelopment and a sustainable approach to the legacy of 1980s architecture that demonstrates how an existing building can be renovated intelligently and, in combination with newly constructed elements, meet the requirements of contemporary architecture as well as that of modern office and residential use.