Municipal heating plans coordinate but do not impose obligations

30 June 2026 marked the deadline for large cities in Germany to develop a municipal heating plan (KWP). These heating plans thus provide, for the first time, a comprehensive vision for heat supply. At almost the same time, the Bundestag abolished the 65 percent requirement for new heating systems with the Building Modernization Act (GModG), and with it the only lever for translating the results of the KWP into obligations for building owners. Which heating technology prevails, whether heating networks are built, and whether buildings connect to them therefore remain voluntary decisions of utilities, network operators, and owners.

These are the findings of the analysis “From Heating Plans to the Heating Transition: What Municipal Heating Planning Achieves in Large Cities and Where It Reaches Its Limits” by the Institute of Energy Economics at the University of Cologne (EWI) on behalf of the Förderinitiative Wärmewende der Gesellschaft zur Förderung des Energiewirtschaftlichen Instituts an der Universität zu Köln e.V. The analysis evaluates the implementation strategies of all 57 published major city heating plans, assesses the limitations of the tool, and discusses options for action both within and outside the scope of the Heat Planning Act.

Municipalities plan most concretely where they can act themselves

All 57 plans call for monitoring progress and retrofitting municipal properties; 50 aim to incorporate heating planning into urban land-use planning; and 45 call for transformation plans for existing heating networks. The plans are most concrete where municipalities take action themselves: in their own buildings, within the administration, and in advisory services. So far, only a few cities, for example Hanover, have implemented binding measures such as mandatory connection to and use of heating networks.

According to the analysis, the structural limitations weigh more heavily than the methodological ones: a heating network operator is obliged neither to build nor to connect, and a gas network operator is not obliged to decommission its network. With the removal of the 65 percent requirement from the Building Energy Act (GEG), owners no longer face any consequences for choosing a particular heating system. In addition, municipal heating planning has methodological weaknesses: assumptions on retrofitting rates and on the availability of green gases can be chosen freely, and the costs of expanding the electricity grid are mostly not included in the cost comparison of the supply areas. As a result, the costs of district heating, heat pumps, and green gases cannot be reliably compared from a system perspective. Yet the regional division in the KWP depends on precisely this comparison.

Binding force comes from outside the Heat Planning Act

Within the context of heating planning, the analysis identifies four options for improvement:

• standardized corridors for scenario assumptions
• better access to data
• network cost metrics for economic feasibility comparisons
• integration with the future distribution network development plans.

These measures make the regional division more robust but not more binding. Instead, instruments outside the scope of the Heat Planning Act may be considered: municipal ordinances to ensure demand for heating networks, provisions in zoning plans, state-level requirements regarding heating system selection, and targeted support for flexibility and retrofitting.

“Heating planning is weakest precisely where the heating transition is decided: in the investment decisions of utilities, network operators, and owners,” says Dr.-Ing. Ann-Kathrin Klaas, Head of Research Area at EWI, who prepared the analysis together with Tobias Leibfritz and Carina Schmidt. “The plans provide a guideline for the heating transition, but implementation remains non-binding.”