To solve the energy dilemma, research effort was concentrated on stand-alone buildings weakly tight to their immediate environment. Specifically in each building only key sub-systems were considered individually. Such individual systems were made more effective by becoming pervasive into any building area (the reign of “boxes” and “controllers”). Importing parameters from other sub-systems allowed better regulations (Access or Occupancy management systems). Energy Usage Analysis tools are fairly new on the market. They provide the capability to analyse energy profiles of scattered buildings of large corporations. Energy usage analysis and planning on a district level is inexistent. Neither is Energy Usage Modelling leveraged in control schemes. This leaves an unexplored area for more effective building control schemes and suggests a potential of each smart building to contribute to District level energy optimization schemes, thanks to appropriate behavioural and stochastic models.In parallel, efforts made many more renewable and cogeneration energy sources available as high capacity energy storage systems. Such systems now increasingly enter into the planning of large districts, but still timidly penetrate individual buildings. Thus, energy flows (electrical or thermal) can be managed through energy usage schemes, planned in time for significant savings.To reach this aim, it is proposed to play in real time adaptive and predictive behavioural models of buildings and districts, exposed to weather conditions, human presence, energy-efficient materials and technologies. Such models will allow finding optimal supply/demand balancing. Building energy management systems will be turned in real-time configurable ones, bringing flexibility to the building. Thus, buildings will establish, in real-time, energy schemes with the district energy management and information system (DEMIS). AMBASSADOR‘s vision: Flexible buildings to make eco-friendly districts.