Swatch Omega Headquarters, Bienne, Switzerland
With 1,997 m³ / 70,523 ft³ of indigenous spruce timber, this campus is one of the largest hybrid timber constructions. The three buildings - the Swatch Headquarters, the Omega Factory and the Museum Cité du Temps – are speaking a uniform design language: they share a common material palette and environmental awareness. Each strategy implemented in the project is designed to minimize global impact and serve as a model for future buildings. To achieve an energy-efficient, comfortable working environment, radiant cooling and heating with activated ceiling panels or water pipes embedded in the concrete ceilings are used. The campus uses the regenerative energy potential of groundwater from wells: for heating, heat pumps "collect" the relative heat of the water from the subsurface. The heat itself is free of charge, only the heat pumps need electricity for operation but deliver considerably more energy than they need for operation. When cooling is required, the groundwater is cold enough to lower the temperature in the cooling circuit of the radiant cooling system via heat exchangers: operation in summer does not require heat pumps. Thus, in addition to the heat, the cold is also regenerative and only takes the rather low amount of electrical energy for the pumping. All roofs carry PV modules on surfaces facing southeast or southwest and cover part of the electricity requirement.
The new office wing with its winding dragon's body seems to reach across the street for the neighboring museum; 240 m / 787 ft long, 35 m / 115 ft wide and 27 m / 88,5 ft high above the street. A bridge on the third floor connects the office building with the "Cité du Temps" across the street. The grid roof construction consists of 4,600 individual wooden elements. Manufactured with high precision, the parts fit into each other. The building concept is geared to the comfort of the employees and increases well-being and productivity: acoustic elements are inserted into the concrete ceilings and a concrete core activation system provides thermal comfort. The mechanical basic ventilation covers the minimum hygienic requirements, the supply air enters the building according to the displacement principle, thus minimizing the risk of draughts and ensuring high ventilation efficiency. There are also operable windows.
Three different construction elements form the facade shell of around 11,000 m² / 118,403 ft²: firstly, there are glass elements, in which triple glazing keeps thermal losses low, with shadings on the outside for best sun protection efficiency; it is covered by a glass pane that protects the shading (closed cavity). Then there are translucent elements with low U-values made of a membrane construction with a special interlayer that allow diffuse light to enter the interior. Thirdly, there are closed elements with the lowest U-value, which are covered with PV where they are horizontally or facing south. The arrangement and proportional distribution of the elements was optimized according to the view (only through the glazed elements), daylight distribution in the room, overall U-value and best energy gains for PV.