Commerzbank Tower – Germany

Commerzbank Tower – Germany

Frankfurt serves as Germany’s financial hub. This skyscraper’s modern design may look clean and simple, but engineers have integrated a number of modern techniques to push for energy efficiency and a relaxed work environment.

Profile:

  • Height: 259m
  • Floors: 58
  • Built: 1997
  • Use: offices
  • Location: Frankfurt – population 780,000

Background:

Tallest building in Europe until 2005, when it was overtaken by the Triumph Palace in Moscow. It is now the tallest in the EU since Britain’s exit. (Apart from London’s Shard and 22 Bishopsgate, every building [there are 10] taller than the Commerzbank in Europe is in Russia).

Capacity of 2400.

Owned by Samsung since 2016.

Design

The tower consists of a 60-metre equilateral, rounded triangle base and cross section with a triangular atrium.

The triangular shape assists ventilation through building by the creation of ‘negative pressure’ – pockets of low pressure air form a natural current as higher pressure air is naturally forced towards these areas.

cross sectional tower diagram

The Commerzbank was one of the world’s first ‘ecological’ skyscrapers – environmental aspects were well considered during the design phase. Some ecological aspects include:

  • ‘Rahmenkonstruktion’ – literally ‘frame construction’ – uses cantilevers and beams to allow for the spanning of floors over nine integrated gardens. These are spaces within the building walls full of various plants and trees, providing a relaxed place to have lunch or meet colleagues.
  • This framed design also reduces the need for artificial light sources since more natural light is let in, reducing energy consumption.
  • The tower uses natural ventilation 85% of the year.
  • Openable windows exist in every office for easy temperature control.

>> Overall, energy consumption is reduced by a half compared to similar office buildings.

  • views over the city from an integrated garden
  • middle triangular atrium used to house an integrated garden

The building has been supplied with exclusively renewable energy since 2008.

The air conditioning system uses ‘Wasserkreislauf kühldecken-System’, a cyclical system that uses the evaporation, condensation and movement of water to control the office temperature. Condensation from this system is used to flush the WCs.

Construction

By architects Foster + Partners. By structural engineers Krebs + Kiefer and Arup, and civil engineers Hochtief.

^ the Commerzbank Tower during construction

The tower stands on foundations of 11 reinforced concrete pillars. The actual building’s superstructure uses a Vierendeel frame system – meaning one made of rectangular members, as opposed to triangular trusses. It reduces bending moments and removes the need for diagonal frame members (which in this case are not aesthetically appropriate) but must be stiffened to provided the desired strength. Here, the frame is made from steel rather than reinforced concrete, reducing weight by a third.

The basement uses a torsion frame (which resists twisting forces) and reinforced concrete walls.

Any timber used in construction came from managed sources.

[Image credits for this page: koreaninvestors.com, billkirkwood.wordpress.com, architecturerevived.com, fosterandpartners.com]