The Kö-Bogen I by star architect Daniel Libeskind has become a landmark in the heart of Düsseldorf, Germany.
Behind its facade of glass and white natural stone, which is broken up with diagonal cuts, is a mix of high-quality shopping, gastronomy and office space.
Two 26m -high buildings offer a floor area of approximately 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 Düsseldorf-based architects 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, thus reducing the building's carbon footprint.
The greenery reduces thermal radiation, stores moisture and reduces ambient noise. It also absorbs as much CO2 as 80 deciduous trees.
The adjacent triangular "food court," which houses the catering facilities, features a walkable turf roof.
Both buildings not only impress with their architecture, but also offer its users the highest level of safety in terms of fire protection.
Kö-Bogen I received the "Sprinkler Protected" seal of approval from the German Fire Protection Association (bvfa) for its comprehensive fire protection measures.
On three floors, the sprinklers are connected with the piping system aquatherm red pipe, which was laid invisibly in the concrete of the floor ceilings.
According to the customer, aquatherm prefabricated all necessary line and supply pipes. This eliminated the need for numerous welds on site, saving not only a lot of time but also manpower.
Also, the tightness test had already taken place in the aquatherm factory in Attendorn in the south of Westphalia, enabling the pipes to be delivered to Düsseldorf ready for installation. In concrete terms, around 3,400 sprinkler connections and 6,500 metres of pipe including fittings were installed in 25 construction stages.
Unlike metal systems, the piping system aquatherm red pipe is welded into a homogeneous, materially bonded, and is safe thanks to fusion. In the 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, according to ARASTI Feuerschutzanlagen project manager for the fire extinguishing system, Jannis Windmüller.
"The architect's wish was to install the sprinkler system directly in concrete. This would not have been possible with a metallic system,” Windmüller said.
“With aquatherm red pipe we got a discreet sprinkler solution in a visually beautiful exposed concrete ceiling for the representative entrance area.”
The laying directly in concrete is made possible by the special material of aquatherm red pipe: the plastic polypropylene, specifically the material fusiolen PP-R FS developed by aquatherm.
It is not only flame retardant (building material class B1), but also corrosion resistant. ARASTI connected approximately 70 sprinklers in the food court area with more than 200 m of aquatherm red pipe piping.