Skip to main content

Kö-Bogen I and II






Düsseldorf, Germany


The challenge

For Kö-Bogen I and the food court of Kö-Bogen II, a sprinkler piping system was sought that was not only safe and made of sustainable material, but that could also be laid directly into the concrete of the floor slabs.

The solution

aquatherm red pipe fulfilled these requirements and ensured among other things that the representative entrance area of the food court received a discreet sprinkler solution in a visually beautiful exposed concrete ceiling.






aquatherm red



Düsseldorf’s prestige buildings receive aquatherm sprinkler system – Sigh safety, sustainability and flexibility – not exactly low demands that were placed on the sprinkler piping system of Düsseldorf’s prestigious Kö-Bogen I and Kö-Bogen II buildings. aquatherm met these requirements with its aquatherm red pipe and also saved time during installation thanks to prefabricated elements.

The Kö-Bogen I by star architect Daniel Libeskind has become a landmark in the heart of Düsseldorf near Königsallee. Behind its façade of glass and white natural stone, which is broken up with diagonal cuts, or “cuts,” is a mix of high-end shopping, dining and office space. Two 26-meter-high buildings offer a floor area of approx. 42,000 m². Due to its sustainable construction, Kö-Bogen I has received LEED Platinum certification.

The adjacent Kö-Bogen II – called KII – is no less impressive: designed by the Düsseldorf architectural firm Ingenhoven, the building with retail and office space also stands out with its unusual facade. 30,000 hornbeam hedges form Europe’s largest green facade, reducing the building’s carbon footprint – an exemplary response to the challenges of climate change. This is because greenery reduces thermal radiation, retains moisture and reduces ambient noise. It also absorbs as much CO2 as 80 deciduous trees can. The adjacent triangular “food court,” which houses the food service, offers a walkable lawn roof.
This sustainable roof invites you to linger in good weather and is a popular meeting place for all visitors.

Safety convinces

Both buildings not only impress with their architecture, but also offer users the highest level of safety in terms of fire protection. For its comprehensive fire protection measures, Kö-Bogen I received the “Sprinkler Protected” seal of approval from the German Fire Protection Association (bvfa). On three floors the sprinklers are connected with the piping system aquatherm red, which was laid invisibly into the concrete of the floor ceilings. All necessary string and supply lines were prefabricated by aquatherm according to the customer’s specifications. This eliminated the need for numerous welds on the construction site, saving not only a lot of time but also manpower. Also the leak test already took place at the aquatherm plant in Attendorn, South Westphalia, so that the pipes were subsequently delivered to Düsseldorf ready for installation. In concrete terms, around 3400 sprinkler connections and 6500 meters of pipe, including fittings, were installed in 25 construction phases.

Unlike metal systems, the piping system aquatherm red is welded into a homogeneous, materially cohesive and thus safe unit thanks to fusion. In this process, the pipe and fitting are briefly heated using tools provided for this purpose and then simply joined together.

The fire protection system proven in Kö-Bogen I was also used in the “food court” of KII. A particular challenge here was the exposed concrete ceiling designed by the architect. “The architect’s wish was to install the sprinkler system directly in concrete. This would not have been possible with a metallic system. With aquatherm red, we got a discreet sprinkler solution in a visually attractive exposed concrete ceiling for the prestigious entrance area,” explains Jannis Windmüller, Project Manager Fire Extinguishing System Construction at ARASTI Feuerschutzanlagen GmbH & Co. KG in Essen.

Laying directly in the concrete

The laying directly in concrete is made possible by the special material of aquatherm red: the plastic polypropylene, specifically the material used by aquatherm developed material fusiolen® PP-R FS. It is not only flame retardant (building material class B1), but also corrosion resistant. By comparison, when metal sprinkler systems are used, corrosion occurs as soon as the metal and wet concrete meet. Corrosion can only be prevented with the help of special protection, which makes the installation of metal pipe systems in concrete complex and expensive.

ARASTI connected the approximately 70 sprinklers in the food court area with more than 200 m of aquatherm red piping. “The aquatherm service technicians supported our personnel very well in the run-up to the installation by providing extensive instruction on the new welding tools,” reports Jannis Windmüller. Things got exciting when the concrete was poured. “Because of the sloped ceiling, some project participants were concerned that the pipes would slip or be pushed elsewhere during the concrete pour,” Windmüller said. “However, there were no difficulties. The piping system – well held to the formwork and reinforcement – stayed in place and is tight.”

Sustainable raw material polypropylene

Not only because of the above described advantages in installation and application aquatherm red proves to be the product of first choice. It is also far ahead of systems made of metal in terms of sustainability and durability. Its material polypropylene – a by-product of crude oil processing – is one of the two most important standard plastics. Life cycle analyses in accordance with ISO 14040 examine the impact of raw material production on the environment. Studies show significantly lower CO2 emissions from polypropylene pipes compared to other raw materials, especially steel. aquatherm has been processing this raw material, which is characterized by long service life, very good environmental compatibility and recyclability, for about 50 years already. The plastic waste resulting from the economic and production process is recycled internally and partially processed into new products.


Find the right contact person for your questions and your project quickly and easily. 


Content of this page