Concept notes and papers
In 2008 the Guardian newspaper in one of its articles asked if the city of Freiburg, Germany (in the black forest) is the greenest city in the world for being a pioneer in the implementation of renewable energies, ecological housing, car-free streets, and the awareness of these issues in its citizens, who consider it as the first Green City. Freiburg also has the first “PlusEnergy” or positive energy house, the Heliotrope, a house that produces more energy than it consumes, a concept developed by the architect Rolf Disch.
