Large two-floor apartment situated near to the Treviso city wall and composed of a large irregular space plus two rooms: the kitchen and the bathroom. The project connects the day-area spaces through a single material (mdf) and a single colour (black) that is distributed through walls that open up into a bookcase, and close in on themselves to form hidden cupboard space, and then arrive at the central heart of the house. The bookcase is a matrix structure designed to hold objects and books of varying dimensions. The kitchen freed from the walls that relegated it to a closed space, is filtered by a large retractable sheet of glass that maintains transparency and consequently the continuity of material and colour.