SERENE is a three-year research and development project funded by the Portuguese Foundation for Science and Technology (2022.08138.PTDC). It focuses primarily on addressing the challenges posed by a significant portion of the building stock in Portugal, which predates seismic design codes and exhibits both seismic vulnerability and energy inefficiency. To this end, SERENE aims to propose and demonstrate an optimal framework for enhancing the seismic and energy performance of existing buildings, minimizing economic and environmental impacts. The project employs a scientifically sound approach, utilizing multi-criteria decision-making optimization and life-cycle performance metrics, integrating hazard, exposure, and vulnerability models to identify retrofitting strategies that ensure sustainability and resource efficiency.