Enig­ma­tic Space

A space that is not reminiscent of anything, that follows no convention and serves no other purpose than to be different from everything else the visitor is acquainted with: the installation in the Swiss Pavilion at the 2016 Architecture Biennale in Venice is oriented towards departure from the familiar. However, the systematic avoidance of historical, technical and aesthetic references is not an end in itself. Instead, the installation is meant to encourage contemplation of how we create and experience architecture – and of what else is possible beyond that. ETH Zurich’s Professor Christian Kerez, architect, and Sandra Oehy, curator, confront the public with a space that unsettles and fascinates in equal measure.

How it began...

The design process began with castings of materials and with the production of hollow moulds. From 300 models, one was selected and digitally captured; different techniques were used, such as optical and tomographical scanning, due to the high complexity of the chosen form. The combination of these techniques and the subsequent ­realisation of the digital model occurred with the help of Benjamin Dillenburger, Assistant Professor of Digital Building Technologies at ETH Zurich. The production of the formwork elements for the planned concrete structure also required a combination of different methods and technologies: the elements were made by means of CNC milling or, when the forms were too complex, 3D printing.

In terms of statics, the installation is a self-supporting spatial shell. However, determining its load-bearing behaviour was anything other than trivial. Very thin shells with double curvature are extraordinarily efficient in a structural sense; but this is a freely formed shell, i.e. a framework that is not formed on the basis of criteria related to specific internal force paths and is statically indeterminate to a great extent. In order to analyse the internal forces and systemic behaviour, civil engineer and ETH Zurich’s Professor Joseph Schwartz applied so-called discrete analysis. This method follows the graphic statics approach, in which, unlike in analytical statics, all mathematical operations are carried out using vector geometry, free of numerical calculations, such that the relationship between force and form also becomes visually comprehensible in the space.

Reminiscent of a grotto

The 1 to 4-cm-thick, glass-fibre-reinforced concrete shell was eventually constructed in a few weeks, in a technically very complex procedure, in the Swiss Pavilion. Here, the structure now stands: an envelope, which looks fragile in relation to its considerable volume, around an enigmatic space within a space. Upon entering it, the visitor leaves the familiar ­behind. The subtly illuminated interior is most reminiscent of a grotto. The visitor can linger within it, look around – and ponder.

Judit Solt, Editor in Chief TEC21, Schweizerische Bauzeitung