Colonia-Haus

After Frankfurt's Grand Tower (completed 2020), the Colonia-Haus is Germany's second-tallest predominantly residential building. From 1973 to 1976 it was the tallest building in the country, and from the planning stage until 1976 the tallest residential tower in all of Europe. Among Germany's 300 tallest high-rises it ranks 21st. The Cologne Uni-Center, completed around the same time, has more apartments (954) but stands at only 134 metres.

Apartments occupy floors 3 to 41, with commercial units on the ground floor and the first two levels. Four high-speed lifts each hold up to 18 people. The building retains a now-rare permit for rubbish chutes on every floor and arranges letterboxes by storey rather than using a central mail lobby. On the ground floor there is a swimming pool with Rhine views (8 × 15 m), a Finnish sauna with plunge pool and relaxation room, and a fitness and table-tennis room. A municipal day-care centre also operates within the building.

The Colonia-Haus was added to Cologne's register of listed buildings in 2015. Balcony damage was first noted in 1985, and a structural survey in 2009 identified concrete deterioration. In June 2023 two cranes were erected on the roof to begin balcony restoration work, with costs estimated at approximately €26–27 million.