A Technical an Loistical Masterpiece
In this design, the most important parts are invisible. Because most of the health and fitness centre, which is actually quite a voluminous construction, is hidden from view. It was mostly built right into the mountain slope. Only nine gigantic pinnacles break the serene mountain landscape, like sails before the wind – what an exhilarating contrast. What could almost be called an architectural understatement required, in fact, the careful pooling of quality construction skills and a comprehensive support structure, but most of all it required a brilliant idea – contributed by the internationally renowned architect Mario Botta.
The Grand Hotel Tschuggen in Arosa, Switzerland, can look back on an eventful history. Founded as a sanatorium for the treatment of lung diseases in 1883, it was turned into a winter sports Grand Hotel in the late 1920s. During that time, Arosa evolved from a quiet spa town to a glamorous winter sports resort. Radically modern buildings designed by famous architects were erected, which still dominate the view of the town today. In 1966, a fire destroyed the entire Tschuggen Hotel property. It was reconstructed and opened again in 1970. In 1980, the Kipp family purchased the hotel and completely renovated it in 2004. The last building phase saw the erection
of the new health and fitness centre.
Those parts of the building protruding from the mountain slope are glass-fronted and, at the back, panelled with the natural RHEINZINK-“preweatheredpro graphitegrey” material. Its timelessly elegant colour avoids garish contrasts and, especially during winter, blends in with the snowy landscape to form a white and grey colour symphony, broken only by the dark green of the surrounding coniferous woodland. Through the large windows, the warm interior light streams out into the early mountain darkness. The building‘s interior is designed in accordingly bright colours. The architecture also captures the natural daylight and reflects it down into the spa area, while on the open galleries built into the light sails, guests can enjoy the view of the surrounding landscape.
From ideas to ideal solutions
The characteristic light sails have a triangular footprint and are arranged on different heights on the slope. In addition to the sails‘ different heights of between thirty and fifty feet, this makes for four different types of sail. Their masses, forms and radii were initially calculated with a 3-D program and rendered in different perspectives. Thus, step by step the many different ideas and drafts eventually led to the perfectly dimensioned light sails. This was followed by the detailed planning stage of the skeleton construction consisting of a load-bearing round tube frame with welding spots at the nodal points. Onto this skeleton, a square tube frame was mounted, which makes the construction sturdier; onto this second frame, the façade, roof and other fixtures were then mounted. At the roof section of this frame, a wooden construction was added, onto which the interior panelling, vapour barriers, insulation, shuttering and the RHEINZINK cladding was mounted.
A technical and logistical masterpiece
As part of the complex realisation of this project, the steel erectors rented an industrial building in the city of St. Gallen for the express purpose of installing a giant metal cube as a mounting template. This was used to ensure that the individual frame parts were set in place accurately to the millimetre before joining them. A CNC-controlled machine then bent the load-bearing tubes precisely into the pre-calculated shapes. The result is a work of precision engineering with a tolerance of +⁄- 5 millimetres. With a height of up to 30 feet and a weight of up to 4 tons, the frame constructions were too unwieldy to be transported whole to Arosa, so they were disassembled, processed accordingly and shipped to Fideris. There, they were reassembled, individually flown to Arosa by helicopter and set down directly onto their foundations.
On top of all these challenges came the fact that, at an elevation of 6000 feet, the building season shrinks to a few months during summer. As all construction and weather risks lay with the contractor, careful labour and time management was of the essence right from the start. Parallel to installing the frames, the individual parts for the wood and RHEINZINK cladding were pre-produced. A total of 19,500 square feet of RHEINZINK-“preweatheredpro graphite-grey“ were used for the roofing and parapets – cut into 780 parts, preshaped and mounted in only seven weeks.
The Tschuggen Bergoase is the perfect example to demonstrate that even the most ambitious construction project can be realised in spite of geographical, climatic, and logistical adversities if all parties involved work hand in hand towards a common goal. In the end, it was also thanks to the comprehensive RHEINZINK consulting services that the Arosa project became the architectonic alpine highlight it is.
Project Data:
Project:
Tschuggen Bergoase by Mario Botta, Arosa, Switzerland
