Twenty-five years ago, Hans Imhoff, the well-known chocolate maker and main Stollwerck shareholder fulfilled a long-held dream when he opened his Chocolate Museum on the Rheinauhafen peninsula in Cologne, in the former harbour customs headquarters, one of the city’s most sought-after buildings. He had first had the idea while moving the Stollwerck factory 18 years earlier, when he discovered a treasure trove of machinery and other material worthy of being displayed in a museum. In 1991, Hans Imhoff bought the entire northern tip of the peninsula from the local authorities, which included the harbour customs building, originally built in 1896, the Malakoff Tower built in 1854 and the steel swing bridge, the oldest bridge in Cologne, over the river Rhine. Plans to extend and refurbish the building were drawn up by the architect, Fritz Eller, (now ninety-one years old) who wanted to restore the historic building to its pre-war glory as since the war only emergency measures had been taken. The design was approved by the Heritage Preservation Commission and while the construction contracts were being awarded, the building was officially registered as one of Cologne’s historic landmarks. After 13 months of building work, the Imhoff Chocolate Museum was officially opened in 1993.

At the northern tip of the harbour, the architect built a glass pavilion in the shape of a ship’s bow to house the production line designed specifically for the museum as well as a three-metre high golden chocolate fountain. On the western side of the customs building, facing the town and the swing bridge, Fritz Eller inserted a glass cube between the building’s two towers. This houses a tropicarium created in collaboration with the University of Bonn, that naturally includes cocoa trees. The design is completed on the southern side by a semi-circular administration building.

To mark the Chocolate Museum’s 25th birthday, the previous exterior lighting system that lit the facades with an even blue light, was replaced with an LED lighting system that marks out the complex, especially from the opposite bank of the Rhine. So the historic customs building is now an important element in the Cologne night skyline, and the structure and details of its facades are accentuated by agLicht’s tasteful lighting design that uses warm white illumination instead of the coloured lighting installed previously.

MaxiWoody LED projectors fitted with Opti Smart lenses and mounted on poles and the adjacent facades ensure that the light is distributed evenly over the natural stone and plasterwork of the historic facade. This basic lighting system is then integrated with floor-recessed Light Up Earth luminaires fitted with Wide Flood optics that create an interplay of light and shadow on the various details. iPro luminaires have also been inserted discreetly in the steel structure of the swinging bridge in an integrated solution that emphasizes the value of the structure’s engineering. On its southern side, the semi-circular administration building is characterised by a grid that is highlighted by 114 Trick luminaires installed at the top centre of the windows, each of which emits a 180° light blade effect. This means that when the lights are turned off in the offices, the building, which stands on an aluminium-coated base looks as if it is floating. In the glazed foyer, iPro projectors have been inserted in the roof structure so they blend in perfectly and emit an even, diffuse and welcoming downlight that is very similar to the effect of natural light. The illumination in this area is particularly important as the foyer houses the main museum entrance, access to the café, the cloakroom, cash desk and toilet area, and is therefore the museum’s main hub where the visitor moves in both a horizontal and vertical direction. In the cloakroom area and on the curved exhibition wall, recessed Laser luminaires also help visitors find their bearings by making the light and spacious atmosphere even livelier.