€30,000 surcharge for geothermal energy sensible? Experiences?

I can well imagine that in times like these, "disposition fees" are also charged by the executing companies. They sometimes create schedules six months or more in advance. Especially for such large development projects. If, for example, the plumbing subcontractor needs an extra week because the client has special requests in one building, it disrupts the deployment schedule for five other projects. You practically have to bribe the subcontractor to really stay longer or to come again. That's just how things are these days.

30,000€ is not an additional charge but a total price, which could only be somewhat justified by including a previously non-existent underfloor heating system with the necessary planning changes. Otherwise, it is simply usury, unless 300m of drilling meters are supposed to be included. I believe the actual message is: You won't get it here, period, end of story. The reasons for this can be manifold.

Thank you for your feedback! Phew, yes, we will see if the developer is willing to enter into talks again with the city or about the zoning plan amendment. Unfortunately, this is not so easy in a "project-related" zoning plan. Everything that is not exactly defined visually requires a subsequent change to the zoning plan. Example: an additional garage door, as it is visually apparent and therefore a deviation from the zoning plan. Unfortunately, we do not have an exterior basement staircase... that was still a question here... We also do not want to come across as "troublemakers." The developer is the client, if I understood correctly, and whether we should write our own letter to the city, we need to discuss with the developer. Just asking, what are “realistic” costs for an air-source heat pump? Provided it would be approved?

. Just asking, what are "realistic" costs for an air heat pump? Provided it would be approved?

Standard heating load air-water heat pump up to 6kw including everything, I would realistically estimate 12-17k for having everything done. You have to offset the gas boiler 5k + buffer + solar thermal modules and connection. The heat pump should maybe cost 5k more. BAFA individual funding is no longer available, right?

Thank you for your feedback! Phew, yes we are checking if the developer is willing to go back into talks with the city or to change the development plan. Unfortunately, this is not so easy with a "project-related" development plan. Everything that is not visually specified exactly as laid down requires a subsequent amendment of the development plan.

And for the third time the question: Is a heat pump explicitly prohibited? What does the development plan say? Doesn’t matter if project-related or "normal". It is and remains just a development plan. Why don’t you answer the question?

I have read through the development plan again from start to finish. In the written text section, there is no indication of a heating type, let alone a prohibition. However, everything is depicted "pictorially" exactly, front side, back of the house, garden, tree, etc. street lamp, garbage bin... so very precise. According to information from the BT, any visual deviation must be approved. Such a "box" in front of the door is visible. I have no legal knowledge of this. I rely on the statement from the BT that it requires approval and that the approval has not been granted. Upon explicit inquiry about air heat pumps. Only geothermal energy was approved. Maybe you can give me a "source" from which I do not have to get this "not" approved, although the development plan depicts all views of the house and property and this is indeed a change? Thank you very much.