When the city hall in Stühlinger, a district of Freiburg, was completed in November 2017, it became the world’s first public net-plus-energy building. It has a gross floor area of 24,000 square meters and provides space for more than 800 employees.  

The special thing about the new building is that it can produce more energy than it needs itself. The public administration building covers its own energy needs and can also feed surplus energy into the municipal power grid. The electricity and energy for heating and cooling are generated from renewable sources such as photovoltaics, solar thermal energy, and geothermal energy.  

The result is that the primary energy requirement of the new Stühlinger city hall is only 55 kilowatt hours per square meter per year, which corresponds to 40 percent of the primary energy requirement of a comparable office building. Thanks to these and other special features, the Stühlinger city hall plays a pioneering role in energy and sustainability. Drees & Sommer’s engineering experts were responsible for the corresponding energy concept, technical building services, building physics, and façade technology. 

In 2018, the building received the German Sustainability Award!