Rehabilitation of Deutsche Bank Towers in Frankfurt

Inaugurated in 1984, the headquarters of the Deutsche Bank, with its twin towers, has long been a symbol of Frankfurt as a financial metropolis. After more than 20 years of use and in view of revised fire-protection requirements, a modernization of the 155-metre-high towers was deemed necessary. Following a comprehensive analysis of the building, a decision was made to undertake a full rehabilitation. In addition to the redesign of the internal spaces, this was to include a complete renewal of the mechanical services. One aim of the planning was to make ecological sustainability a central point of reference and to achieve a substantial improvement in the energy efficiency of the development. As it turned out, it was possible to effect savings of 67 per cent in the use of heating energy, 55 per cent in the use of electricity and 74 per cent in water consumption. A further major aspect of the refurbishment was the renewal of the facade. The old glazed outer skin was replaced by triple glazing, and the insulation in the space between this and the load-bearing concrete structure was increased to a thickness of 14 cm. Another innovation is that half of the windows can now be opened, thereby allowing natural ventilation of the internal spaces. As a result, the facade has assumed a more lively quality, while still retaining its characteristic appearance.