Interregional cooperation is fundamental to improve the effectiveness of local sustainable energy policies, as a response to overarching EU strategies and commitments. The RENERGY and RE-SEEties projects represent valuable international cooperative experiences, which have proved that the transfer of knowledge among scientific institutions and local authorities, can support a real synergy among politicians, businesses and citizens and the achievement of the main Covenant of Mayors targets. Both the projects produced a methodological toolkit aimed at supporting local authorities in creating a sustainable and resource efficient future giving rise to local implementation plans ready to be endorsed. The RENERGY project, aimed at developing efficient energy policies at regional level in an inclusive, integrative approach, focused on the transformation of urban communities from consumers to producers of energy. The RENERGY toolkit had the purpose to provide local authorities with a roadmap to develop their Local Implementation Plan (LIP). The methodology was tested by 11 partners' countries giving an innovative and positive approach to local energy policy whereas good practice exchanges, Energy Labs and Case Studies contributed to the transfer of knowledge and to increase local communities awareness. The RE-SEEties project was aimed at contributing to the resource efficiency challenge by investigating on energy consumption and waste production and disposal, examining the role of potential changes in consumption patterns and policy making alternatives to support the achievement of resource efficiency targets. A comprehensive approach to energy and waste flows at urban level was thus adopted in order to reduce the overall carbon footprint of cities. A step by step methodology was devised to approach jointly energy and waste issues, whereas structured initiatives were promoted to support a change of behaviour and a tight cooperation between municipal officers working on different themes. The interest aroused within and beyond the involved communities as well as the important results achieved in these two projects testify the importance of a proactive engagement of local governments and communities on energy and climate themes as well as the necessity of adopting a long-term comprehensive approach to ensure a socially inclusive growth and a steady transition towards a low-carbon society.