The "West Arcade" building at KfW headquarters in Frankfurt, equipped with a special WICONA façade construction, was awarded with the "CTBUH 2011 Best Tall Building in the World Award” of the international Council on Tall Buildings and Urban Habitat (CTBUH). The CTBUH evaluated the design, the technical innovations applied and energy efficiency as well as the building's impacts on the city in which it's located and inhabitants.
Already being touted as one of the most energy-efficient office buildings in the world, KfW Westarkade is projected to use approximately half the energy of an average European office building, and one-third of a US-based one. A bespoke double façade construction for unitized assembly was specifically designed by WICONA for this requirements. The building addresses the prevailing wind direction to exploit it for controlled natural ventilation of the offices by means of its double-layered façade, which allows for the building to be naturally ventilated eight months out of the year.
The attractive facade design with elements in three colours executed as double skin façade in a unitized system was developed specifically by WICONA for those object-specific requirements. The new building completes the already existing building- ensemble of the “Kreditanstalt für Wiederaufbau” (KfW) from the 1970th, 1980th and 1990th. The Sauerbruch Hutton Generalplanungsgesellschaft Berlin mbH won the first price in a competition of 19 architecture offices. The client chose this draft because of urban development measures, architectural, functional and environmental reasons.
An aluminium double skin facade surrounds the office tower with its 13 floors. The construction of the “interior façade layer” is based on the window system WICLINE 77 with concealed sashes or fixed glazing. Storey high, colourful turn sashes open outwards and let light and sun into the office floors. This part of the aluminium double façade creates a thermal case and permits natural ventilation. A mechanic ventilation system supports this process in case of bad weather conditions: a horizontal thrust ring ventilation. The ventilation flaps open and close depending on wind direction and they assure an optimal heat ventilation. In cooperation with the professionals of the FKN façade GmbH & Co. KG in Neuenstein a special construction for the “external façade” was developed.
The plan of the architecture firm Sauerbruch Hutton combines form, colour and sustainability. The building already won the CTBUH prize for Europe in the summer. With a primary energy consumption of 98 kWh/m² per year, the "West Arcade" has one of the highest eco-standards in the world for office buildings.
Peter Murray, award juror, comments: “The streamlined form integrates itself into its surrounding context, while simultaneously standing out through the playful use of color. Whereas many buildings use color as a way to mask an otherwise unremarkable building, here it contributes an additional rich layer to what is already a remarkable building.”
"We are very pleased with the award this extraordinary building has received. We see the West Arcade as a symbol that demonstrates how it is possible to combine very high energy efficiency with impressive architecture", said Dr Ulrich Schröder, Chief Executive Office of KfW Bankengruppe. "KfW not only actively promotes energy efficiency but also practices responsible management of the environment and climate in our own buildings. All the better that we also receive a prize for these efforts."
The CTBUH is headquartered at the Illinois Institute of Technology in Chicago. The internationally oriented organisation supports exchange between architects, engineers and designers of high buildings. The award was accepted yesterday evening by Axel Hinterthan (KfW), Matthias Sauerbruch and Louisa Hutton (Sauerbruch Hutton) in "Crown Hall" in Chicago designed by the famous German architect Mies Van der Rohe.