Abstract: Disclosed is a system for optimizing energy utilization in a multi-building development or community. In an embodiment, the system has a passive energy loop comprising a continuous liquid filled pipe. A plurality of energy transfer points connect a plurality of buildings in the development onto the passive energy loop. A system control center adapted to control the plurality of energy transfer points to extract excess thermal energy from or input required thermal energy to each of the plurality of buildings, thereby to optimize the energy utilization and minimize greenhouse gases produced by the system.