Nowadays, the use of building automation and control systems is currently growing faster through the European continent, aiming to improve the energy efficiency, the building performance monitoring and to better respond to occupants' needs. In 2018, the revised Energy Performance of Building Directive EU 2018/844 (EPBD) has introduced and updated a set of concepts with the aim of reach the total decarbonization of the European building stock, together with the reduction of the greenhouse gas emissions within the 2030, respecting a minimum thresholds fixed at $-40\,$\% of the levels registered in 1990. For the first time, an indicator for the evaluation of the smart readiness of buildings has been introduced at the EU level, for which the adoption is still voluntary from the European member states.