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

The heating technology is stated in the building application, so simply switching is not so easy if the authority objects. The issue with gas, I see here not only in the costs but in the fact that this gas heating system certainly cannot be replaced with another gas heating system. Even regarding existing rights, I would have a question mark in the medium term. Owners of a Euro5 diesel know what to make of that in case of doubt.

At this point, I would also tend to an indoor unit. I cannot imagine that the municipality can seriously prohibit that. A surcharge of 30,000€ is also quite something.

Somehow I can't keep up. If I switch from gas to an air-water heat pump in the inventory and the noise emissions are okay, the municipality won't notice. How do they then prohibit that in new buildings?! I would look for indoor units, you will never recover 30k, I wouldn't want gas either.

Official inquiry in the municipal council or to the mayor as to whether such a regulation is still tenable in times when every cubic meter of gas must be urgently saved for political reasons. Including reporting in the regional press. The municipal council will quickly become flexible...

P.S.: I would still be interested to know on what grounds air-to-water heat pumps are not approved!

I am also very interested in that. I am not a fan of air-to-water heat pumps and would like to know what reasons a municipality has to prohibit them. My favorite so far is geothermal energy and I really hope that we can switch in 2-5 years.

Switch from gas (standard) to geothermal energy? According to BT, additional cost about €30,000.

We are also initially building with gas, as air-to-water heat pumps are not an option for us.

- is it sensible to install gas and then switch to geothermal energy in 1-2 years with other subsidies?

We are hoping for that too. First of all, we just want to live in a house with heating and hot water. If there are subsidies for geothermal energy then, we want to switch. If our house builder (prefabricated timber frame construction) had offered geothermal energy, we probably would have taken it, even for €30,000, even if we had to save money elsewhere.

The heating technology is specified in the building application, so simply switching is not so cool if the authority objects.

What bad luck if the gas heating breaks down quickly and a new gas heating is no longer possible once the legislator puts a stop to it.

In this respect – however, the OP still owes a few answers – prepare everything for the heat pump so that the device simply has to be installed (maybe in 2025?).

Thank you very much for your responses so far! All of this gives me/us a lot of food for thought! So, the background: It is a "project-related development plan" and it does not provide for an air heat pump. Whether that can still be changed in such a short time, I don’t know. Without this "very restrictive" development plan, I believe that in general an air heat pump cannot be rejected. In this specific case, however, it probably can. We are building with the BT: everything from the plot to the garage from a single source. The BT also offers, for an additional charge, to size the planned (!) underfloor heating more narrowly and to design it for a heat pump. However, he advises against retrofitting geothermal energy. Reasons: difficult to lay cables retrospectively, "hole" in the facade, cables in the basement, etc. Unfortunately, we lack the knowledge of how "dramatic" the effort for retrofitting geothermal energy is? Can you say something about this? Option B: Internal heat pump: We have requested it. Cost estimate is still pending. According to verbal statements, almost as expensive as geothermal energy, since the concrete basement has to be cut, etc. We could get along with... a) Gas - and then preparatory measures for switching in a few years: what should one think of besides the underfloor heating? b) Air heat pump: seems not "wanted" (noise and low efficiency were also mentioned) - as I said, we are already in the middle of construction, whether a letter to the mayor would still help... and then we would not want to do it "without the consent" of the BT anyway, since they are the "builders" 3) Geothermal energy.... at own cost.... what are "normal" costs for geothermal energy in new construction? I have read 18,000–25,000 and the 30,000€ we found expensive, still waiting to see exactly how that breaks down. 4) Funding retroactively: Are there "minimum waiting periods" after new construction? It’s really crazy, house newly built 2022, gas out 2023 with funding?? Oh yes: The house has 180 sqm including basement. Thanks again!!