Anyone with a knowledge of architectural history will be reminded of Farnsworth House. However, the new Fellows Pavilion of the American Academy in Berlin differs from that icon of modern architecture both in terms of its spatial arrangement and its constructive concept. The pavilion stands on the shore of the Wannsee, at the old garden wall of the Academy’s grounds. From the historical main building, which is on a small hill, visitors first see the intricate structure from above, which explains the meticulous design of the roof.  The new building creates more space for the ever-increasing number of fellows. A central corridor leads to seven study rooms and a kitchenette. All the spaces are delimited with wood-clad walls, while the corridor side is glazed, as are the sliding doors leading outside. Curtains ensure a degree of privacy. The wooden deck of a wraparound verandah continues inside as hardwood flooring. The floor plan is deliberately simple, other than the roof, each of whose four sides features an obtuse pediment. The view of the roof is symmetrically divided into four rectangles in the curved shape of a hyperbolic paraboloid. The geometry of four clusters of straight lines twisted against each other creates four apices in the middle of the roof edge. This presents a contrast to the four low points found at the building’s corners and – as a spatial surprise – a fifth in the middle. This entire figure can best be appreciated at dusk, when the building is lit from within.  Above the partitions and glass façade, joints divide the roof surface into nine prefabricated framing elements. The view from below features double-walled steel ribs arranged lengthwise along the building. Each of these consists of two 5-mm-thick framing pieces welded together 10 mm apart. This pincer-shaped construction enables the undetectable attachment of the roof structure by means of screws at exactly the same distance. The roof cladding is made of narrow strips of steel sheeting that are fixed to the supports with pressure bars. Because the roof surface is curved, the steel strips would have to have been cut in a slightly trapezoidal shape, but the tolerance created by the perpendicular strips means that the high number of elements can be taken on in the pressure-bar joint. In order to ensure that the roof sheds water, the thickness of the sprayed insulation above the lowest point of the roof is raised to the extent that it creates a slope along the roof’s diagonals. The corner joints at the ends let the water flow downwards.  Contrary to what might be assumed from the building’s appearance, the roof does not rest on the corner supports alone. Rather, the supports are statically oversized; they are meant to join the floor slab and roof as a single visual entity. In fact, a large portion of the roof burden is carried by the 16 narrow, U-shaped steel profiles arranged at the ends of the partitions in the floor slab, which is also made of steel. The walls hold both the heating elements and the cross-bracing, making them an integral component of the static system.  With this project, the architects have taken up neither the structurally independent floor plan nor the flowing spatial concept of Mies’ 1951 masterpiece. Instead, the Berlin pavilion celebrates the roof, executed here in a strictly geometric design. This roof presents an elaborately constructed, detailed crown to a simple floor plan.