Ecca collection

The building, in Hansastrasse, is impressive not just for its energy saving credentials but also for its unusual undulating steel facade with its ice-like surface finish. 

The upgrade covered all parts of the building. For example, the entire structure is insulated with polyurethane, supplied by project partner Bayer MaterialScience. And 108 photovoltaic panels supply the building with electricity, with excess energy being stored in batteries. 

“As far as electricity supply is concerned the building is self-sufficient,” says principal architect Anna Vering. And should the solar energy run out, the building switches to green electricity produced entirely from water power. The heating system has also been well thought-out: two geothermal boreholes – each 100 metres deep – keep the inside of the building pleasantly warm even in the winter. 

In addition, radiant ceilings heat and cool the rooms, allowing optimum temperature control even on hot summer days. And when the geothermal energy is not adequate, the building is also connected to a district heating network. Triple-glazed windows and a ventilation system with 90% heat recovery make for optimum performance. 

“The building is a showcase for energy efficiency,” explains Vering. “We want to encourage other architects and owners to upgrade old buildings.” 

The special nature of the building is reflected in its undulating facade, she adds. “We looked for a material that would allow us to create these undulations – and at the same time offer a special finish.” Another requirement, she adds, “was that the material should blend in with the streetscape – and be ecological”. 

The architects found just what they were looking for in PLADUR Relief iceCrystal from ThyssenKrupp Steel Europe. The surface of this high-quality flat carbon steel appears as if covered in ice crystals – hence its name. Used until now mainly in industrial construction, for rainscreen facades, this is its first application in a high-end multi-storey building. 

“PLADUR Relief iceCrystal is visually fantastic,” says Vering. “What excites me most are the clear edges it allows you to create.”

The ice-like facade offers several other advantages, not least the fact that it is scratch-resistant and dirt-repellent, and protected effectively against corrosion by having been galvanized and organically coated. It therefore resists both the weather and ravages of time, says ThyssenKrupp, “and in so doing preserves the value of the property”. It also compares very favourably with other building materials in terms of value for money, the company adds, as well as being recyclable – without any loss of quality. 

PLADUR Relief iceCrystal is easy to process, and can be bent, drawn, folded, profiled, stamped, joined and bonded – without cracking and without any loss of strength. This makes it suitable for standard parts and individually formed panels of the type used for the building on Hansastrasse. 

“Fabrication went very smoothly,” confirms Lars Werner, managing partner of HSP-Fassaden, the company that shaped and installed the panels. “Although the steel is only 1.25 millimeters thick, it has enough stiffness – and doesn’t buckle,” he adds. 

The idea behind the building upgrade also convinced the judges of the InnovationCity Ruhr initiative, which have named it Germany’s first Energy Plus office building. 

“Our concept for the property on Hansastrasse won the commercial building category of the competition,” says Vering. “It involved working very closely with Innovation City.” The aim of the initiative is to encourage climate-friendly urban renewal and contribute to the regeneration of the industrial town of Bottrop. In concrete terms it means reducing CO₂ emissions by 50% and enhancing quality of life.”