Construction Study - AARAU Bus Station

Instructor: Julia Koerner  ︎
Site: Aarau, Switzerland
Year:  2021 Spring
Team Work - Case study

    A unique structure, which roofs the main bus station in the Swiss town of Aarau, was built at the end of 2013. The canopy has a cloud-like shape and contains the largest single-chamber cushion in the world.

    Architects Vehovar & Jauslin with engineering firm formTL, have constructed a large floating structure that stands over the town’s bus station in Aarau, Switzerland. The main frame supports the curve edge where the membranes are fixed and reshaped by the cable system. The transparent canopy is made from an upper blue and lower clear ETFE-foil, printed with a bubble pattern that together creates a sinuously formed air-tight cushion that is butt-welded without visible repetition. The necessary utility lines for drainage, lighting, recirculating air and measurement technology run invisibly inside the construction. This cable-supported pneus is the world's largest inflated cushion built very airtight and energy efficient.

    The cushion is enveloped and spanned by an irregular mesh of stainless steel cables that are fixed to the curved pipes on the edge. The edge beams are supported by a load bearing system consisting of steel girders lying within the cushion. 

The entire technical infrastructure for water, air, electronics and sensor technology has been integrated into the inner steel structure.

    The roof is supported by a total of 11 filigree columns made of round pipes that are slightly inclined in an axis.  The "cloud" seems to float. The ETFE cushion has such an airtight and energy‑saving design that merely 15 % of the forecast air power needed to sustain the structure is required.