The interventions in the ‘Planeten Flats’, which from both architectural and technical points of view was a monotonously repetitive, building, were so spectacular that in 1993 the renovation project was awarded the ‘National Renovation Prize’. In particular the architectural changes which resulted in a clear position of the entrance, the changes in the facade that divide the building into three distinct horizontal layers, and the spacious winter garden with a multi purpose function, give the building a pleasing integrated modern look. In themselves the techniques necessary to reach the architectural goals were not spectacular, but the many technical difficulties that had to be faced are worthy of description. These include different temperature movements in elements that are partially standing and partially suspended and the complicated method used to remove bearing walls and replace them by prefabricated concrete columns to bear the steel beams as supports for the bearing walls above.