Heating and cooling (H&C) accounts for about half of Europe’s total energy needs with 75% still dependent on fossil fuels. Thus, rapid and significant change is needed to reach the EU 2050 goals. Due to the local nature of H&C systems, action has to be taken at local level involving a variety of stakeholders. This has been recognised in recent years and activities have been started like developing best practice policies and open source analysis tools. However, (efficient) H&C planning and project development are still not commonplace in most European municipalities. The objectives of Act!onHeat are to further disseminate and take up the concept and methods for strategic H&C planning, increase its quality and to push the development and implementation of identified measures. To reach these goals Act!onHeat will implement the following activities: (i) identify the success factors of strong and efficient existing H&C plans and develop a workflow for strategic H&C planning and project development based on the existing open source tools Hotmaps and THERMOS, (ii) support at least 120 municipalities in strategic H&C planning and the development of at least 30 pre-feasibility studies for related individual projects with a mix of tailored individual and group support activities, (iii) train stakeholders who can actively contribute to decarbonisation in the use of workflows, processes and tools through a dedicated training programme, and (iv) leverage additional impact with a mix of Europe-wide roadshow events, acceleration dialogues, webinars and further promotional activities. The consortium is perfectly suited for these activities bringing together leading European experts in strategic H&C planning and policy analysis, local governments networking, capacity building and investment support. A remarkable number of letters of support show the interest of the target group as well as the well-established connections between the target group and the consortium members.