In the 1990s, a Viennese dairy firm vacated its innercity location, and young media enterprises began to discover the spacious premises in this industrial building. In the end, all that remained unoccupied was a small space on the roof, built originally to house a water-storage tank. Plans were made to convert this 18m2 room into a dwelling. An extension would have been feasible only by strengthening the flat roof at a considerable cost. The architects therefore sought to exploit the existing area to the full and to create the feeling of a spacious ambience. The first step was the removal of the water tank. The sloping support on which it was seated is still visible. In the area where there is no problem in providing the minimum headroom required for the staircase, this bearing surface was extended up to the outer wall, where a window allows additional daylight to enter from the west. Part of the external wall supporting the roof was then replaced with large, room-height, glass double doors that afford a view out over the roofs of the city. The new floor, in glass-fibre-reinforced concrete with a sealed surface, is continued externally without a threshold to form an outdoor paved terrace and a visual extension of the living area. Mounted on the sloping surface at the rear of the flat is a “kitchen sculpture” in welded sheet steel. Integrated into this are a hob and waste bin. The refrigerator is suspended from the ceiling above. The shower, too, is reduced to a minimum. It consists of a stainless-steel tray sunk in the floor, with the fittings simply attached to the wall. In other words, one showers in a small spatial recess that forms an extension of the main space. The revolving steel drum built into the wall between the living room and the toilet is a playful device: it houses the television, which can be turned and viewed from either side. The most striking idea for achieving a maximum effect with a minimum of space, though, was to have the table, bed and cupboard in the room only when needed. At other times, they disappear through openings in the outer wall into lightweight, insulated extension structures.