Caterpillar - An Experiment in Fabrication

Innovation excels through limitations. In the case of the project for a restaurant addition to an existing hotel in the Swiss Alps, the primary constraint was that construction would have to be limited to a period of six weeks. It was clear from the outset that prefabrication techniques had to be used in order to comply to the tight schedule. The entire planning phase of approximately one year was directed toward the design not only of the building, but most importantly of the sequence of construction procedures on and off site. Design encompassed the design of processes. 

The building had to be assembled in parts: the larger the members, the faster and more efficient the assembly. The local timber industry was willing to collaborate. Based on discussions with manufacturers, strategies were identified as to the most resourceful application of available technologies. Selected finally was a type of hybrid construction combining both digital and analogue techniques. Computer integrated manufacturing was used to accelerate the fabrication of the pieces – allowing a direct transfer of digital information from the architect’s office to the machines in the woodshop. While the primary structure was digitally cut, analogue procedures were used for the construction of the modules. Not surprising, in this respect, was the craftsmen’s request to reduce the difference between the individual elements in favor of a repetition of similar parts: the more identical the units, the more proficient the manual work. 

The final assembly had to be meticulously choreographed. In order to assure a high degree of coordination between the various trades, the entire structure was erected indoors – in a local factory hall – prior to the beginning of construction in situ. Sequences were rehearsed and progressively improved. This part of the work led to the pre-assembly of large modules, comprised of structural components, thermal insulation, electrical wiring, duct work, and enclosure.  The size of the units was determined by transportation restraints, specifically by the height of a highway overpass along the route from the factory to the site. 

The building consists of a total of eleven modules, interlocked with one another to form an entity. Whereas the units are designed to perform as distinct frames, it is only through their interconnection that structural firmness is attained. As each module is slightly tilted, a visual game ensues between the instability of the parts and the stability of the system – a distortion effect being conveyed. The building’s fleeting quality is furthermore emphasized by the silver-gray color of the zinc cladding. Taking on the quality of a snakeskin, the layers of scales glimmer in the sun light. 

Key to the entire assembly are the gaps between the modules. These spaces are framed with glass, resulting in a repetitive rhythm of openings for the passage of light. What emerges in formal and spatial terms is a sequential arrangement of open and closed wedges – a caterpillar-like assembly of seemingly crawling parts. Rumor has it that the building tiptoes on the ground. When covered in snow, the impression of a camouflaged structure is suggested, merging the building with its surroundings – nothing but a series of irregular bumps in the landscape. 

What was explicitly an exercise in technology is in effect an exploration of architecture’s sensorial properties, its latent potential to activate the senses. Working from the exigencies of real construction, the project evolves into the domain of the affect: architecture as a machine à émouvoir – the metamorphosis of a caterpillar into a butterfly.