Positive energy districts (PEDs) are central in the global transition toward sustainable, decentralized, and self-sufficient energy systems. Energy transformation taking place locally in cities may trigger broader sustainability transitions (STs) toward PED ecosystems at macro level. The work adopts a service ecosystems perspective to tackle the complexity of STs in the energy sector. The work builds a conceptual framework intended to support the transition and renewal of PED service ecosystems at a micro- and meso levels and uses illustrative case examples from a PED located in Espoo, Finland. The framework is intended to map the interdependencies between different actors in commercializing PED service ecosystems, and acts as a transformational tool for the public and private organizations to address change in PEDs. The framework concretizes the value propositions, actor roles, resource integration, and monetization mechanisms, as well as the transformation enablers, challenges, and long-term impacts. Additionally, the goal of the framework is to help municipalities to understand their roles in strengthening the institutional and social enablers for the local energy transformation with clear regulatory frameworks, incentive mechanisms, long-term political commitment, and vision. Overall, the study supports our understanding on the underlying mechanisms in the paradigm change toward sustainable energy systems.