Bark box

Bark box

STÄFA (CH) - In 2004, e2a architekten won the competition to renovate part of the 1970s Obstgarten (Fruit Orchard) auditorium with library in Stäfa, on the north shore of Lake Zurich. The brief was to give the concrete blocks an aesthetic makeover while also improving their energy efficiency. The classrooms underwent a metamorphosis. The typical brown atmosphere of the 1970s made way for a fresh, white, much lighter interior. The buildings were also wrapped in a thick layer of insulation, but one that did not compromise the image of the original complex: the architects opted for fair-faced concrete facade panels.

The new auditorium (600 seats) with library, which replaces the former concert hall, is the heart of the campus and its most striking building. The auditorium interior is pure white, like the classrooms, and has generous skylights, but from the outside the structure stands in stark contrast to the other austerely designed buildings. The new concrete facade is decorated with an all-round relief in the form of an organic pattern derived from a photo of the bark of an apple tree. On the one hand this refers to the original function of this area (orchards), on the other the relief makes the massive, imperforate concert hall volume appear lighter, as well as tactile.

The photo of the tree bark was converted into a digital file (positive) and then milled into Styropor moulds (negative). A total of 167 concrete panels, with the same number of different motifs, were cast in these moulds and installed precisely in accordance with the predetermined pattern. (Kirsten Hannema)