The heating sector, Europe-wide and in the Baltic Sea Region (BSR), has huge impact on climate change as it accounts for a large share of greenhouse gas (GHG) emissions. One lever to positively steer the developments in this area is “local heat planning (LHP)”, an instrument to depict sustainable and economically viable transformation paths and measures towards a GHG-neutral heat supply at municipal level. The EU Energy Efficiency Directive (EED) recast 2023 now includes a new provision, which requires Member States to ensure that municipalities above 45,000 inhabitants prepare local heat plans that respond to increased EU obligations in the upcoming years. However, many BSR municipalities are not prepared for this extensive task, they lack know-how and resources for LHP as well as the awareness for their long-term responsibilities in decarbonising their local heat sector. PlanHeat addresses this challenge by bringing together municipalities and expert organisations from seven BSR countries that jointly develop a transnational manual on how to prepare local heat plans. This guiding manual comprises five sub-solutions on the topics data access, technologies, staff and skills, stakeholder participation as well as financial and organizational solutions for LHP. Relevant target groups like heat suppliers, energy consultants or ministries responsible for energy and climate policies will be strongly engaged in the project. The PlanHeat manual will be disseminated all over the BSR.