The architects designed a pragmatic yet aesthetically pleasing building. The structure consists basically of a concrete skeleton frame with a simple, pitched roof covered with corrugated fibre-cement sheeting. During the construction of the carcass, the architects consulted two colleagues about the facade infill panels. In the context of a research project at the Department for Architecture and Digital Fabrication at the ETH Zurich, they had developed prototypical wall elements assembled by industrial robots belonging to the institute. Inspired by the construction task, the consultants saw the concrete skeleton structure as something resembling an outsize basket. In a computer simulation, they allowed spheres of different diameters to fall like grapes into the virtual container. By turning the individual bricks – in stretcher bond with open vertical joints – they were able to make the facade resemble this image. Since the industrial robots were directly programmed with the design data, it was possible to prefabricate the infill elements at the ETH within two weeks. They were then brought to the site and put in position by crane. The open-jointed brickwork provides the requisite sunshading, while reducing the direct entry of light and ensuring an almost constant temperature for an optimal fermentation process. Internally, transparent polycarbonate sheeting provides protection against wind and moisture.
As part of their research work at the ETH in Zurich, Gramazio and Kohler are developing production processes for architectural elements. For this purpose, they built a CNC industrial robot plant with which students have been able to create prototypes of wall elements. The infill units for the vineyard extension are an ongoing development of this work. The 400 m² facade area in the skeleton-frame structure is divided into 72 segments and filled with some 20,000 engineering bricks. To achieve the “grapes in a basket” effect, the bricks were rotated about their axis, creating an interplay of light and shade. The variations in grey tones were analysed by computer. To ensure stability, the bricks were rotated by a maximum of 17°, and at the edges of the units, they were laid straight. While the brick courses were bonded with epoxy-resin-based adhesive, the vertical joints were left open. The architects had only three months to complete the building. By feeding the design data directly into the robot (MAYA computer program) it was possible to produce the wall units within two weeks. A pneumatically controlled adhesive pistol was also integrated in the robot to automate the bonding process. Since the bricks are turned at different angles, the overlapping areas vary. Four parallel adhesive strips were extruded, therefore, to ensure an even bonding strength (approx. 8 kN/m²). No additional reinforcement was necessary.
