This single-family house made of reinforced concrete is conceived both as an urban mansion and a penthouse. Its volume, which plays with the heights constraints, is centred on a large “public” staircase acting as a patio. The different apartments like areas of the family members all abut on this central room. The living-dining area is the larger space. It is thought as a penthouse under the slant roof with a kind of clerestory windows, which emphasizes the relation to the skyline of the city prior to the related surrounding.