Achieving energy self-sufficiency for a 35,000 square foot building in a highly dense urban fabric is a formidable task, for which incorporating net-zero strategies cannot be an afterthought but ingrained in every design decision. The Unisphere is one of the world’s largest net-zero commercial building located in Silver Spring, Maryland, Washington DC. Some of the energy efficiency measures taken are: openable windows which automatically change tints depending on the weather conditions. Moreover, air circulates through a quarter mile-long concrete labyrinth 12 feet underneath the building, providing passive heating and cooling—the labyrinth tends to be cooler than the outdoor air in the summer and warmer in the winter. The building uses a geothermal system to condition the spaces in the summer and winter. Natural daylighting illuminate the spaces and artificial lighting is equipped with daylight controls. The energy is generated through 3000 solar panels.