This unusual house with a U-shaped layout and a clear facade articulation has been carefully integrated into an undulating, landscaped site on the edge of a wood. The reinforced concrete structure is faced on the outside with a rear-ventilated skin, consisting of large precast concrete elements that extend up above the roof slab. In their coloration and surface texture, they underline the solid volumetric expression of the building. Blastfurnace ash and crushed Nero Ebano stone were mixed with the concrete to achieve a black pigmentation. The irregular surface texture was formed by inserting latex moulds in the shuttering to create the appearance of a rock-like structure. After setting, the concrete was subjected to a special acid-cleaning treatment. The surface thus achieved can appear rough-textured or soft and velvety, depending on the incidence of light. Contrasted with this are the large window openings incised in the volume.