An existing house was completely demolished, including the basement, to make way for a new dwelling. The exterior walls of the first floor do not fully align with the load-bearing lines of the ground floor, as the ground floor has a larger footprint than the upper level. This is compensated by a 21 cm-thick concrete slab, which benefits from the favorable effect of the cantilevered terrace overhangs. To avoid thermal bridging, the slab was insulated both above and below. To reduce costs, a solution with wide-slab floors was adopted, partially supported on cast-in-place steel profiles and partially on upstanding concrete beams.