"A scalable, replicable, high energy efficient, zero emissions and cost effective SYSTEM to refurbish existing public-owned non-residential buildings to achieve at least 50% energy consumption reduction through:a) A systemic methodology for optimal building retrofitting towards zero emissions, developed to ensure cost effectiveness, scalability and replicability of the interventions taking into account external (geographical, climatic, resources, social) and internal (envelope, facilities and use) building boundary conditions.b) Development of demand reduction strategies: Based on envelope U-value improvement through innovative technologies, material applications and design techniques.c) Development of Energy reduction strategies: An effective interaction and integration of an innovative, scalable, high efficient renewable HVAC hybrid cogeneration system fed with locally available RES, including thermal energy storage strategies as the core of the methodology´s implementation.d) Effective interactions of energy flows: building to building, building to electrical grid and building to heating and cooling networks and improved methodologies for interconnectivity of smart grids and heating and cooling networks under the control of a building level energy operation system.Buildings will be considered as single energy-consumption units and at the same time, connected to other buildings forming high energy efficient districts prepared to be connected with other districts around. These energy units will be able to provide advanced energy services (electrical and thermal) to other buildings in their district, which will make the building strategies replicable al district level in order to attract investments.0’"