Cofrastra® 40: significant flexibility and high efficiency for LEED Gold certified Tower 185

Germany's fourth tallest office building in Frankfurt's Europaviertel has 54 floors and a total height of 207 metres. Thanks to more than 76,000 m2 of ArcelorMittal's Cofrastra 40 composite floor sheets, which were used for the flooring system, significant space optimization could be achieved.

Detailed information

Tower 185 is a new generation skyscraper and marks the dawn of a new era of responsible and environmentally friendly office buildings. In addition to the sustainable design in all functional areas, this also includes the highly flexible use of space.

The tower forms the entrance to the Europaviertel, a new business district that is being developed between the Frankfurt banking district and the exhibition grounds. It lies in close proximity to the Skyline Plaza shopping and convention centre.


Rising up out of a six-storey horseshoe-shaped plinth building with a natural stone façade are two multi-storey highrise buildings with an aluminium-glass façade that enclose a central glass structure.

The skyscraper was designed by Frankfurt architects Prof. Christoph Mäckler Architekten. According to Mäckler, the architectural symbolism stems from a rematerialised modernist design epitomising both timeless elegance and a sustainable use of increasingly scarce resources.

Tower 185 fits perfectly into the environment and is in line with the surrounding urban architecture. The materials used create tension in the composition and meet all conceivable aspects in terms of aesthetics, functionality, ecology and economy.

Sustainability: an intelligent energy concept

Tower 185 was designed as a Green Building and meets the LEED Gold requirements. LEED (Leadership in Energy and Environmental Design), developed by the U.S. Green Council in 1998, is an internationally recognised classification system that defines the guidelines for environmentally friendly, resource-saving and sustainable building. As such, it is continuously adapted to current requirements.

The intelligent energy concept of Tower 185 is based on all main LEED categories and guarantees long-term stable and low costs.

- 50% of the tower façade is closed in order to save heating and cooling energy and thus operating costs and also to reduce CO2 emissions. Floor-to-ceiling windows that can be opened manually guarantee best natural light and ventilation. The rotunda, which connects the two highrise buildings, is made of an impressive glass façade. Since it faces the north side, it is not exposed to sunlight.

- The use of 2.3 million litres of rainwater per year (for toilet water and watering of green areas) reduces the fresh water consumption of the building.

- 25% of the property consists of green areas, including the flat roof areas of the plinth building.

- Ecologically friendly materials were used.

- Over 90% of the construction waste was recycled and a central construction site logistics concept reduced energy consumption for waste disposal by approximately 65%.

- By using building materials from the region, short transport routes and thus lower CO2 consumption were ensured.

Optimisation of space utilisation

Tower 185 offers significantly higher efficiency and flexibility compared to conventional space utilisation. Due to its specific floor plan and the generous room height of three metres on all storeys, 35% more individual offices can be accommodated per storey. Furthermore, each storey offers 54 window work places and eight corner offices.
Overall, the building has more than 100.000 m2 of rental space.

At the floor level, the plinth building with its horseshoe-shaped floor plan forms an area surrounded by arcades that also serves as an access area for vehicles. The arcades are occupied by restaurants and shops.

Additional amenities include the building's daycare centre, underground parking garage with 551 parking spaces, electric charging stations, 170 bicycle parking spaces and optimal access to the public transport system.

According to the developers, the lift system is very advanced and guarantees short waiting times: The ten high-speed lifts travel at a speed of seven meters per second.

Construction within the time frame

After only 33 months of construction, Tower 185 was completed within the planned time frame and budget of 450 million Euros.
The massive structure consists of reinforced concrete and is designed as a tube-in construction. The utility service shaft and the façades are load-bearing elements.

As for the ceiling system of the highrise, HOCHTIEF AG, the company commissioned with the construction of the tower, opted for the use of the high quality Cofrastra 40 composite floor panel system developed by ArcelorMittal Arval.

An important advantage of this system is the quick installation time, a fact that significantly accelerated the construction phase.

In total, ArcelorMittal Arval supplied more than 76,000 m2 of Cofrastra 40 panels for the floor system of "Tower 185".

Project Information

  • Frankfurt on Main
  • Germany
  • Architect:
    Prof. Christoph Mäckler Architekten
  • 2008 - 2011
  • Constractor:
    CA Immo Deutschland
  • Photographer:
    ©CA Immo; ©ArcelorMittal Construction Deutschland

Technical details