SEEDS unites a multidisciplinary and complementary team of SMEs, LEs, RTOs, and stakeholders that constitute the whole (local) value chain of energy efficiency in buildings and thermal demand electrification, from planning, design, and construction to operation and commissioning. SEEDS is built upon the consortium's vast experience in developing, testing, and valorizing decarbonization solutions, supervising real-life demonstrations of building renovation and smartification, and deploying energy flexibility. SEEDS demonstrate replicable heat pump solutions integrated with renewable energy to decarbonize buildings' thermal demand. Addressing that every building is unique and requires tailored solutions to be cost-efficient and energy efficient, we develop scalable and generic design and operational optimization methodologies, deploy multiple proven heat pump technologies at scale, and optimally integrate them into the building and broader energy system. SEEDS demonstrates these (up to TRL6-8) in 6 pilot sites (incl. 1 replication site), providing real-world settings spread across the different climate zones and European construction markets. SEEDS is centered around three key themes: cost efficiency through optimization, system integration through holistic design and control, and replicability through configuration modularity and scalable building types. These are addressed in 7 focus areas: 1) Iterative design of the component and integrated system, 2) Secure and interoperable data platforms and IoT, 3) Integrated system optimization for energy efficiency and flexibility, 4) Deploying energy flexibility to enhance grid stability, 5) Replication strategies, exploitation, and business models, 6) Decision making support framework for replication, and 7) Dissemination, communication, and stakeholder outreach. Thanks to the 27 partners' wide-reached field of impact and networks, SEEDS is set out to boost the electrification of thermal demand in buildings.