Commerzbank Tower

Commerzbank Tower is a 56- storey, 259 m (850 ft) skyscraper in the Innenstadt district of Frankfurt am Main, Germany. An antenna spire with a signal light on top gives the tower a total height of 300 m (980 ft).

It is the tallest building in Frankfurt am Main, the tallest building in Germany and the second tallest building in the European Union. It had been the tallest building in Europe from its completion in 1997 until 2005 when it was surpassed by the Triumph-Palace in Moscow.

The Commerzbank Tower is only two metres taller than the Messeturm, which is also located in Frankfurt. The Messeturm had been the tallest building in Europe before the construction of the Commerzbank Tower. Commerzbank Tower was designed by Foster & Partners, with Arup and Krebs & Kiefer (structural engineering), J. Roger Preston with P&A Petterson Ahrens (mechanical engineering), Schad & Hölzel (electrical engineering). Construction of the building began in 1994 and took three years to complete. The building provides 121,000 m (1,300,000 sq ft) of office space for the Commerzbank headquarters, including winter gardens and natural lighting and air circulation. The building is lighted at night with a yellow lighting scheme that was designed by Asadullah Aftab who was allowed to display this sequence as a result of a competition.

In its immediate neighbourhood are other skyscrapers including the Eurotower (home of the European Central Bank), the Main Tower, the Silberturm, the Japan Center and the Gallileo, the latter being also owned and used by Commerzbank. The area forms Frankfurts central business district, commonly known as Bankenviertel. When the building was planned in the early 1970s Frankfurt's Green Party, who governed the city together with the Social Democratic Party, encouraged the Commerzbank to design a 'red' skyscraper. The result was the world's first so-called ecological skyscraper: besides the use of 'sky-gardens', environmentally friendly technologies were employed to reduce energy required for heating and cooling. Commerzbank Tower is shaped as a 60 metres (197 ft) wide rounded equilateral triangle with a central, triangular atrium. At nine different levels, the atrium opens up to one of the three sides, forming large sky gardens. These open areas allow more natural light in the building, reducing the need for artificial lighting. At the same time it ensures offices in the building's two other sides have a view of either the city or the garden. In order to eliminate the need of supporting columns in the sky gardens, the building was constructed in steel rather than the conventional (and cheaper) concrete. It was the first skyscraper in Germany where steel was used as the main construction material.