Conversion of an existing three-storey residential building into an offices building. The building design program required the addition of one floor. Our proposal was a metallic floor, constructed in a niche, preserving the basic tracing of existing facades. At the same time, it constitutes a complete, autonomous part which allows the existing building’s vertical completion without the addition’s interference.  Design also included the creation of an esoteric atrium, which connects different floors and provides natural lighting to an enclosed space, which – due to its previous use – was relatively complex and labyrinthine.