Going green is the mantra for just about everybody these days, so it is no surprise to see that just like charity, going green begins at home. With the roof over your head in particular, as designers at Rolf Disch have come up with a net positive city in Freiburg, Germany, which is capable of producing up to 400% the amount of energy it consumes. Dubbed the Sonnenschiff (Solar Ship) and Solarseidlung (Solar Village), these cleverly utilize buildings will comprise of a series of large rooftop solar arrays which will also function as sun shades simultaneously. Not only that, these buildings were built to Passivhaus standards which further lowers the amount of energy required for heating and cooling. The entire development comprises of 52 homes with space for commercial facilities. Other eco-friendly technologies used include phase-change materials and vacuum insulation which will boost the thermal performance of the building’s wall system.