City Hall Freiburg, Germany

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

Its standout feature: the building produces more energy than it consumes. It meets its own energy needs and feeds surplus power into the municipal grid. Electricity, heating, and cooling are generated entirely from renewable sources such as photovoltaics, solar thermal energy, and geothermal energy.

As a result, the primary energy requirement of the new Stühlinger city hall is just 55 kilowatt hours per square meter per year — around 40 percent of that of a comparable office building. With these and other special features, the building sets a pioneering standard in energy performance and sustainability. Drees & Sommer’s engineering experts were responsible for the energy concept, technical building services, building physics, and façade technology.

In 2018, the building received the German Sustainability Award.