In order to achieve the desired climate neutrality, it is essential to phase out fossil fuels as far as possible. Oil and gas heating systems are still very prevalent in the provision of space and hot water heating in small municipalities with a predominance of single-family homes. Alternatives in the form of heat pumps, district heating or pellet heating systems must be made possible in order to facilitate the switch to other heat supply systems. This means that new district heating systems must be built in good time - if they already exist, "only" an increase in capacity would have to be implemented - and or the capacity of the electrical lines must be increased in order to be able to connect a large number of heat pumps.

Solid heat space planning - or even better energy space planning - at the level of small municipalities seems to be indispensable. How could such heat room planning be carried out cost-efficiently and who could take on the role of protagonist - especially against the background of necessary gas network decommissioning or dismantling of oil and natural gas heating systems on the one hand and expansion/reinforcement of electrical lines and district heating systems on the other. The idea that this heat room planning should be taken over by the natural gas network operator encounters several - almost insurmountable - hurdles. As already mentioned, the alternative options must be available in good time - i.e. before the switch to district heating or heat pumps. As the gas network operator does not have the authority to dictate to the electricity network operator or the district heating operator when the respective electricity or district heating operator must have created the alternative option - especially as this would indirectly interfere with their profit-relevant business (keyword "management responsibility"), the gas network operator can at best have the gas network decommissioning plan approved by the authority. The competent authority would then have to check whether the alternatives can be made available in good time and subsequently oblige the electricity or district heating network operators to create the infrastructure.

This process would entail at least a doubling of the workload. The idea of motivating the gas network operator to decommission the gas network cost-effectively by providing incentives also appears to be difficult to realise, as the gas network operator is unlikely to fight against its own interests. The definition of economic efficiency criteria for the decommissioning of natural gas networks could lead to the following situation since - as already mentioned - alternatives or the possibility of an alternative solution must be available in good time:

• in the event of a switch to district heating, 2 systems would not be well utilised for a relatively long time and would have to be operated in parallel. The utilisation of the district heating network would slowly increase while the utilisation of the natural gas pipelines would slowly decrease. As a result, the number of cost units in both systems would be lower than possible over a long period of time, meaning that the specific energy transport costs in both systems would remain high. In the natural gas network, the specific transport costs would rise more slowly than possible, while in the district heating network they would fall more slowly than possible;
• the utilisation problem described would also occur when laying electrical lines - either for the installation of heat pumps - if possible - or for the connection of electric heating systems.

What to do? Here, a comparison with the implementation of wood chip-fuelled district heating systems in small villages almost comes to mind. Wood-fired district heating systems were implemented in order to minimise the negative effects on the climate caused by oil and gas heating systems and at the same time to promote the region (recycling of waste wood and creation of jobs, etc.). Mostly, this initiative was based on personal climate protection reasons, tangible economic interests of forest owners or comfort reasons.

In the initial stage, the idea was worked out within a small group, mostly with the involvement of the local council - as far as possible - and the investment amount and the specific heating costs derived from this were estimated in very rough terms. Information events were then organised, in which the municipal representatives played an important role, and individual households were asked about the intended switch to district heating. If there was sufficient interest, the project was intensively promoted and usually realised. A similar approach to the "district heating realisation procedure" described above could be taken when phasing out fossil fuels for heat supply. The municipality or its representatives know best which districts could be supplied by district heating, heat pumps or pellet heating systems. By knowing the "mood" among the neighbours, noise nuisance problems, for example, could best be brought under control. Ideally, purchasing groups could be organised in order to be able to buy the equipment - for example heat pumps - and the installation of the same at a reasonable price.

The results of this heat room planning would have to be bindingly agreed with the gas network operator and approved by the relevant authority. The costs incurred in the course of the planning process (costs for the information event, travel expenses for the protagonists, etc.) could be covered by village development programmes, for example. But first of all, the necessary legal basis must be created in the Condominium Act, the Commonhold Housing Act and the Tenancy Act. Would this be feasible?