The overall vision is to operationalise energy efficiency first principle in the practical context of buildings, towards the decarbonisation of the EU building stock, through: Electrified low-carbon technologies such as heat pumps for the electrification of the building thermal energy demand; Integration of RES & storage; Building digitalisation and intelligence with smart energy management systems. To achieve the ‘META BUILD of the building sector’, we will develop and demonstrate at TRL 6-8 highly cost-effective, integrated and replicable solutions (i.e. Heat Pumps coupled with RES and ES systems) for electrifying thermal energy demand in buildings. Social acceptance and strict adherence to energy efficiency measures will be ensured to promote a sustainable, efficient energy use and an affordable pathway to decarbonise the building-sector heating. A holistic approach addresses challenges throughout the building life cycle, including product manufacturing, energy solution design and engineering, construction, renovation, operation, and maintenance. META BUILD will deliver: KPI-driven assessment methodology & LCA analysis on building electrification; Decarbonisation as a service decision support tool; sound Business Models combined with energy efficiency and electrification; Advanced HP technologies, PVTs & other RES solutions, thermal & second-life battery storage systems; Interoperable framework for electrified ready buildings; Energy management services for RT-monitoring & performance analytics; Demand response, grid interaction & flexibility planning tools; Pro-active maintenance & controls services; Digital Twins for maintaining/enhancing the buildings’ performance; Blueprints & policy recommendations for replication & scalability. Focus will be given on both construction and renovation phases of a building, while META BUILD solutions will be demonstrated and replicated in different types of buildings including 6 Front Runners and 7 Replication Multipliers.