Opernturm Frankfurt am Main, DE
The new OpernTurm enriches Frankfurt’s skyline with an impressive high-rise building. Viewed at ground level, the building, built according to a design by Christoph Mäckler Architekten, Frankfurt, gives the Opernplatz a frame on its west side.
It thus restores the clearly defined representative space around the opera building as it was created here in the 19th century. The building consists of the tower and a seven-storey podium building. This takes up the perimeter block development of the 19th century.
Project data
Architect
Christoph Mäckler Architekten, Frankfurt a. M., Germany
Client
Tishman Speyer, Frankfurt a. M., Germany
Construction
Josef Gärtner GmbH, Gundelfingen, Germany
Glass supplier
Schollglas Sachsen GmbH, Nossen
View of Opernplatz
Corresponding to the opera building, its façade was made of yellow sandstone. Two-storey arcades with shops and restaurants give the currently deserted square back its urbanity, and from a roof terrace you can enjoy the view of Opernplatz. Behind it rises the 168 m high OpernTurm. It is entered either via the Galeria – a glass-roofed incision in the podium building – or via an impressive four-storey entrance hall on its south side. Classically, the tower is divided into a plinth area up to the 4th floor, a middle section with office use and a striking head with a city loggia on the 41st floor, which offers a wide view over the city.
Demarcation from the Frankfurt skyline
The expressive plasticity of the entire building catches the eye. It was important to the architects to set themselves apart from the smooth shells of the office towers that dominate the Frankfurt skyline. Therefore, in reference to the façade of the opera, the decision was made in favor of sandstone. The special feature of the OpernTurm façade is that it is not curtained, but actually carries over the entire height of the tower itself. In the so-called “tube-in-tube” construction, the development core and the outer shell are designed to be load-bearing. On the 40th floor, they are connected to each other in a stiffening manner. The architects deliberately used the depth of the sandstone façade resulting from the construction to make it possible to experience it three-dimensionally. In addition, it acts as constructive sun protection. The windows are deep in their reveals, which is visually enhanced by the dark profiles and narrow aluminium ventilation sashes.
Slender proportions stretch the building
Vertical incisions that deepen upwards, which run along the entire height of the tower in the middle of each side of the tower, give it slender proportions. Finally, in the area of the 41st and 42nd floors, the sandstone façade separates from the glass on the west and east sides. A post-and-beam construction set back by approx. 4 metres from the sandstone front forms the outer shell. In contrast, glazed steel structures are placed on the front sides of the tower on these floors.
23% less energy consumption
In order to emphasise the plasticity of the sandstone façade, the glass of the entire building should be barely noticeable, i.e. it should have a high proportion of white. This is where the advantages of GEWE-therm® insulating glass came into play, which offers effective thermal protection when viewed neutrally and can be equipped with additional functionalities. All of the tower’s 12,000 m² of barrel glazing was made of GEWE-therm® sun with the HS 51 high-selective coating. From a height of 120 m, especially on the south side, additional radar-absorbing equipment for the glasses was required due to Frankfurt Airport. For the glass roof of the Galeria, insulating glass was made of GEWE-safe® laminated safety glass in combination with half-tempered GEWE-tvg®. To prevent overheating, they were also given the Sunguard Solar silver grey 32 sun protection coating. To protect against noise, the shop windows were additionally equipped with acoustics.
The natural stone façade in combination with the high-performance glazing used makes a decisive contribution to the fact that the OpernTurm will consume 23% less energy than required by the Energy Saving Ordinance. For this, it is also one of the first office high-rise buildings in Europe to receive gold certification according to the US environmental standard LEED.
