PHOENIX aims at changing the role of buildings from unorganised energy consumers to active agents orchestrating and optimising their energy consumption, production and storage, with the goal of increasing energy performance, maximising occupants’ benefit, and facilitating grid operation. The project will design a portfolio of ICT solutions covering all aspects from hardware and software upgrades needed in legacy equipment and optimal deployment of sensors, to data analytics and services for both building users and energy utilities. PHOENIX will take advantage of artificial intelligence technologies, as well as edge/cloud computing methods, to provide the highest level of smartness to existing buildings. To achieve this ambitious goal, PHOENIX relies on a consortium which has the technological knowledge and expertise to understand the social and technical requirements and translate them into ICT innovations (i.e. IoT, AI and Data Analytics) for the integration and smartness upgrading of existing buildings with legacy equipment and systems. To demonstrate the real impact and replicability, the proposed solution with ICT innovations and cost-effective services will be validated in 5 different pilots at European level (i.e. Ireland, Greece, Sweden and Spain). Moreover, the consortia have high expertise and business capacities to disseminate and exploit the PHOENIX results.