Making public buildings smarter and more energy efficient requires tailored solutions to overcome the barriers in implementing suitable technology options in a large variety of building types. The PrioritEE project aimed to strengthen the policy-making and strategic planning competencies of local and regional public authorities in the energy management of Municipal Public Buildings, gaining experience in five local pilots in the Mediterranean area. This paper focuses on the PrioritEE toolbox, describing both the “soft components” and the technical components. These components are widely applicable and replicable in all European cities for supporting local administrations in improving energy efficiency and the use of renewable energy sources in municipal public buildings. The Energy Technologies and Building Retrofit Database is a technology repository of energy efficiency measures and renewable energy technologies, providing the main reference data on costs, technical performance and lifetime. With the Decision Support Tool users can assess current building stock energy performance, evaluate different efficiency and renewable interventions, and compare, rank, and prioritize technical options through a set of key performance indicators. A sample of the results to date in the five partner regions are also presented, comparing the main individual characteristics in order to derive replicable solutions for local authorities. This project also highlighted how crucial stakeholder involvement is for tool improvement, capacity building and enabling knowledge transfer.