Polygeneration is an integrated process that produces two or more energy products from one or more primary energy, sources (PES). Polygeneration systems have wide applications in utilities, industrial sectors and building sectors. However, there are still very limited applications of the powerful and practical optimization techniques in polygeneration systems of building sectors comparing to their wide applications in industrial sectors. System optimization is one of effective and reasonable tools to exploit the potential of polygeneration systems. Polygeneration offers potential to fulfill the ambitious target of zero energy building (ZEB) because the interdependence of different energy products can be utilized to provide advantage and flexibility to accommodate more renewable energy sources (RES) in the system. Polygeneration based ZEB can be treated as a type of Polygeneration Microgrid (PM) because PM represents a promising solution to supply electricity, heat and cooling efficiently using local energy sources, including RES. The development of PM is closely associated with building applications.