In 1951 the telecom company moved into the new building, designed during the Second World War by municipal architect J. Koops. The building was designed up as an urban block, consisting of two parallel wings more or less identical in size. An office wing on Botersloot, the representative side of the plot at the time, was combined with an industrial wing full of telecom equipment at the back of the complex, facing the railway. But by the end of 1990 the surrounding area had changed significantly. The railway viaduct had been replaced by a tunnel with a new market square on top, and several neighbouring buildings were demolished and replaced by new ones.

The existing masonry was cleaned and kept in sight and the building was insulated from the inside. All window frames were renewed, while several window openings were enlarged by surgical interventions and replaced with recessed French balcony doors topped by panoptic windows. A long balcony on the third floor adds a three-dimensional twist to the previously rigid window pattern and the apartments on the roof level all got loggias.

The ceramic roof tiles on the south side have been replaced by glazed solar slates in a neutral, dark colour. As a result, they are practically invisible, preserving the high-quality aesthetic appearance of the roof. The energy concept has been customized for this building. Residual heat from the telecom equipment in the basement is used to preheat the tap water and the floors in the apartments and restaurant. Water is also heated with solar boilers on the flat roof at the rear of the building. The building is heated and cooled with electric heat pumps. Enough energy is generated to supply the needs of almost all apartments and some of the restaurant.

Now that the transformation has been completed, and the building has been inhabited for around 1.5 years, it is really great to see this once dead spot in the heart of Rotterdam come back to life. Public programmes enliven the plinth, people occupy the adjacent terraces, and apartments and outside spaces are intensively used. Reusing and enhancing what was already there has radically transformed the building and surroundings from a dark, neglected and isolated corner of the market square into a vibrant city-centre space. In this way the project underlines the new Rotterdam attitude towards transforming and maintaining existing buildings, an attitude that has increasingly evolved over the past decade from demolishing and replacing buildings to transforming and reusing them instead.