The K20 Art Collection in Düsseldorf is home of one of Germany’s most important contemporary art collections. When the State Chancellery of North Rhine-Westphalia decided to update and expand its original 1986 home two years ago, the administrators tapped the architects of the existing museum, the late Arne Jacobsen’s Copenhagen-based Dissing+Weitling. As they had to shutter the facility to execute the renovation and 21,528-square-foot addition, they also called upon the Bonn-based lighting design firm Licht Kunst Licht to overhaul the dated lighting system. With numerous museums in their portfolio, Licht Kunst Licht principal Andreas Schulz and lighting designer Alexander Rotsch