Baumschlager Eberle Architekten

Description

The prominent office building from the 1970s has been sensitively transformed into a new phase of its life cycle without losing its character. Refurbished in accordance with the 22•26 hybrid method, the building exemplifies how much potential is inherent within seemingly challenging existing building stock when mass, material and space are understood as active climate components. The façade’s materiality draws on the existing structure, with rhythmic cladding and a ground floor set apart from the rest of the building by a wraparound band. The façade is overlaid with strongly profiled cornices and pilaster strips, referencing traditional uses of these elements. Thanks to the 22•26 hybrid method, building services, energy consumption and greenhouse gas emissions have been drastically reduced, resulting in low operating and maintenance costs. The removal of the suspended ceilings exposed the necessary thermal mass to efficiently store or release heat. Mechanical ventilation has been replaced by controlled window ventilation, which is used for night-time cooling in summer. Opaque façade elements reduce the proportion of glazing, counteracting overheating in summer. In the colder months, the waste heat given off by appliances and users helps to heat the interiors. A geothermal heat pump serves solely to provide peak coverage for heating and cooling. Bio-based materials such as clay building boards and clay plaster create a pleasant and healthy indoor climate. The office building is the first in Switzerland to be nominated for the BREEAM Refurbishment label in the Outstanding category.