Cities, communities and neighbourhoods are centres of our coexistence, but also centres of our energy consumption. More than 50% of this energy is needed to provide heating and cooling for space heating, hot water and processes. An energy turnaround is therefore primarily a heating and cooling transition. AEE INTEC develops, demonstrates and optimizes supply concepts for district heating or smaller grid-based solutions. Simulations, intelligent data evaluation and spatial planning tools are valuable instruments that are constantly being further developed to meet the growing complexity of our energy system. In addition to digitization and storage and generation technologies, the integration of other energy systems such as electricity and gas networks as well as infrastructures such as wastewater and mobility offer enormous potential for making a turnaround in heating and cooling technically, ecologically, economically and socially sustainable.