After renovations, eleven UN organizations moved into the building and it began serving as the center of the UN Campus, Bonn.

In March 1965, Egon Eiermann, one of the most prominent German architects of the period, received the contract for the design and the artistic management.

In 1979, an emergency exit stair tower was added on the Rhine side of the building after plans of Eiermann's student, Georg Pollich.

The required renovations were handled by the North Rhine-Westphalia state construction company and cost an estimated €54 million.

On March 31, 2006, ownership of the property was transferred to the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety.

At the beginning of May, three large, lighted UN-emblems were added to the roof, though for technical reasons, one could not be placed on the Rhine-facing side.

Also as part of the security preparations for UN occupancy, a 700-meter fence was built encircling the UN campus and an adjacent road was closed to traffic.

After the renovations, there is room for approximately 675 employees in the building, though some floors remain empty for future UN institutions to occupy.

Preservationists justified their decision, stating that the building, with its eschewal of hierarchical elements in the facade design, was a “vivid example for the understanding of democratic construction in the young West Germany.”