The white volumes of the extension structures to the nursing school are accentuated by areas of local limestone used in an unusual form: as a perforated skin around the circular staircase, and as a fascia to the lecture-hall wall. The stones to the staircase were laid with openings between them and fixed with adhesive. The effect of light and shade heightens the sculptural impact of the cylindrical volume. In contrast, the wall to the lecture hall has a planar texture. Only the outer face consists of stones, which are cast into a rear layer of concrete. Recycled from demolition work without further treatment, the stones were laid in the formwork with interstices between them that were filled by the concrete.