A distinct building has risen up on the former site of the Lotto Tower, close to the Central Station in Brussels. The project fits into the redevelopment plan for the ‘Pentagon’ of Brussels, the historical city centre which lies between the boulevards of the inner ring. The oval tower has a total of 18 stories, three of which are underground. The designers set one of the floors further back than the others in order to break up the massive appearance of the building, and part of the building was designed with an overhang. The stability study was carried out by VK.

The building’s location, along a busy main road and a metro line posed quite a challenge. It was decided that only the central structure containing the vertical circulation would be cast on site. The stories were stacked using prefabricated materials, which demanded a long period of preparation and intensive consultation. The oval form required additional calculations and as many floors as possible were constructed using prestressed cell-shaped floor slabs. Each floor has a patio, but each is integrated in a different location. Ultimately, several varieties of prefabricated columns and posts were used. This combination of techniques allowed this building project to be completed in record time, only 18 months.

Large atria on several levels of the building span 5 floors. Steel columns filled with concrete were used to support this part of the structure. The type of ground upon which this building is built required that it be founded on piles.