This article elaborates on the development and role of the Solar Info Center in the City of Freiburg, Germany. In 1998, the idea of the Solar Info Center was conceived with the vision to create a service center for all aspects of sustainable building and habitation, from renewable energy and energy efficiency to eco-friendly construction materials. Today, whatever a customer might be looking for - whether it is technical competence, planning, consultancy, project development, product engineering, Research and Development (R&D), education and training, legal advice, events, exhibitions or education - everything in the field of renewable energy and energy efficiency- it can be found at this marketplace. The building of the Solar Info Center features a rational, sustainable and ecological energy and technology concept and is the first certified office building in Germany to be heated emission-free by 100 %. Three years in the official monitoring program of the Federal Ministry of Economics and Technology verified the low energy demand for heating of 26 $kWh/m^2a$.