Main Forum is a building complex designed by Gruber + Kleine-Kraneburg on the northern bank of the Main river between Untermainkai and Wilhelm-Leuschner-Strasse. Main Forum consists of an 80-meter-high tower and a five-storey ring building. Main Forum offers space for around 1,400 employees. The apartments are located exclusively in the lower building. The Main Forum building houses the headquarters of the IG Metall union and is therefore colloquially known as the IG Metall high-rise.
Main Forum has around 46,680 square meters (502,459 square feed) of floor space and was designed according to energy-saving principles. Instead of full air conditioning with chillers, a system of pipes below the main forum is used for cooling. During the cold season, Main river water flows into the pipelines, which can be used for cooling in the summer months.
In order to save energy even in winter, the facades are designed differently depending on the cardinal points. Therefore, the south side is provided with a closed natural stone facade for heat storage. Seen from the Main, the building appears to be divided into two parts. The west side has a reddish natural stone facade, while the east side is glazed. The windows in the office can be opened.
The foundation stone for Main Forum was laid on May 28, 2001, and both buildings were completed in 2003 after a construction period of almost three years. The construction costs for the ensemble were around 125 million euros.
On the ground floor of the Main Forum tower there is a 20 meters (66 feet) high atrium that connects the building parts and the L-shaped inner courtyard. Here you can find the installation “Utsurohi” (in English “A moment of movement”) by the Japanese artist Aiko Miyawaki. It is a body of water with a chrome-plated steel cable construction that is constantly in motion.
In the Main Forum building there is also an approximately 1,000 square meters (10,764 square feet) conference area. The largest conference room (“Conference Room North”) is also rented out to external organizers by IG Metall.
Status June 2002: The IG Metall high-rise is being built by construction company HOCHTIEF AG.