Construction costs are currently skyrocketing

For the passive house, unlike the Gebäudeenergiegesetz standard or the KfW efficiency houses, there are no technical minimum requirements and currently no suitable funding framework. The former probably conditions the latter. There is only the German Passive House Institute, which specifies a target value that the annual heat demand must not exceed 15 kWh/m² and the heating load must be a maximum of 10 W/m², with airtightness of less than 0.6/h at 50 mbar pressure difference. The specifications are purely physically justified by the type of heating only through reheating the supply air. The 10 W/m² can still be achieved with the given minimum air exchange at just under 40°C. With a higher heating load, more air or a higher temperature would be required. Deviating from this, one can of course also simply use infrared heaters or other electric direct heating instead of reheating the air. I would recommend electric surface heating for maximum comfort.

Then you can save yourself other heating systems (except perhaps electric underfloor heating in tiled areas, especially the bathroom for comfort). I have not heard of anyone building an EH40 with such minimal heating. Is a fully comprehensive air heat pump with water underfloor heating so cheap that people prefer to forgo the extra energy consultant costs for PHPP and some extra insulation measures for a higher building standard (serious question)?

From a certain living space size, the additional central heating as an air-water heat pump together with electricity cost savings is simply cheaper again than the extra effort for PHPP planning and additional insulation. Probably the construction costs balance out and then in the end the higher electricity costs of direct heating remain against the additional maintenance costs of the heat pump.

Or is the surcharge really that high? Or is there so little trust in science and energy consultants (perhaps rightly so) that it can also work?

Most energy consultants will not recommend passive house planning, similar to how most heating installers prefer to plan an oversized heat pump. The main thing is not too cold and if it goes wrong, you’re the fool. Additionally, the user must also fit the house with appropriate behavior (ventilation) and the construction supervision must be carried out meticulously (keyword thermal bridges and especially airtightness at windows and connections).

In the normal case, with poor construction execution, there may be 3-5 W/m² more heating load and you do not notice because the heating system manages that as well. In a passive house, this leads to 18°C in the living space.

For the passive house, you should have confidence in your abilities and preferably also gain experience in this field as a planner with colleagues with corresponding knowledge before tackling it independently. The examples mentioned with passive house owners whose buildings do not get warm confirm this.

Overall, the passive house has not really established itself as a standard, but most of the knowledge in modern construction (airtightness, minimum air exchange, avoidance of thermal bridges) ultimately stems from earlier research and construction projects related to the passive house and has been adopted from there.

Sure, that is offered and installed very often. Bien-Zenker offers it as standard for their 40s houses. Feel-good climate heating. So air-air heat pump. Streif Haus as well. There are various providers who rely on it.

Schwörerhaus and Weberhaus as well. The Ott houses here in the settlement almost all have Proxon too, even down to the old building energy law. It's simply cheap and possibly an upgrade to underfloor heating will still come out of it. The three- to fourfold operating costs are then paid by the buyer.

Friends of mine lived in an apartment (Miete) without heating. There was only an electric heater in the bathroom. The end of the story was electric fan heaters in every room. It was so semi-cozy…

Friends of mine lived in an apartment (rented) without heating. There was only an electric heater in the bathroom. The end result was electric fan heaters in every room. It was kind of uncomfortable...

Blowers are the most uncomfortable thing you can have. But at least the rent reduction for an apartment without heating should have compensated the electricity costs.

Gas currently costs me 10.38 cents/kWh, heating electricity would be 25.11 cents/kWh. The gas boiler maintenance costs 200 EUR, about the same as the heat pump inspection plus the meter for the heating electricity, however you set it up.
The builder wanted a surcharge of 12,000 EUR for the heat pump compared to gas. If I assume an unrealistic annual performance factor of 4 for the air-to-water heat pump and need 10,000 kWh of heat, I come to a saving of 410 EUR per year.

29.3 years before it pays off.

And no, photovoltaics is also not a solution, because you first have to have and invest the 10,000 EUR for the system on the roof...

Great for the green conscience and at the tea party in the eco-shop... economically pure nonsense ;)

Gas currently costs me 10.38 cents/kWh, heating electricity would come to 25.11 cents/kWh. The gas boiler maintenance costs 200 EUR, so roughly the same as the heat pump inspection plus the meter for the heating electricity, no matter how you set it up.
The builder wanted an extra 12,000 EUR for the heat pump over gas. If I assume a utopian annual performance factor of 4 for the air-water heat pump and need 10,000 kWh of heat, I come to a saving of 410 EUR per year.

29.3 years until it pays off.

And no, photovoltaic is also not a solution because you first have to have and invest the 10,000 EUR for the system on the roof...

Great for the green conscience and at the tea party in the eco-shop... economically pure nonsense ;)

Well, those are just the builder’s markups. Somehow he has to make money too.

Besides, a "maintenance" of the heat pump by third parties is not necessary. You can do all the important things yourself (mainly checking and cleaning), saving yourself both the boiler maintenance and the chimney sweep.

For heating electricity, regular electricity is enough except in southern regions, here in central Germany just under 25 cents.

Therefore, the amortization will come much faster. But for the extra cost, you can actually push a lot of emissions through the chimney. However, if the prices of the energy sources (politically intended) develop differently over the next 20 years, the pendulum can swing much faster towards the heat pump. Increasing CO2 pricing for gas will be unavoidable and has already been decided.

And those who install a photovoltaic system in new buildings not just as a solution but because it makes sense as a good investment (self-consumption of general electricity, electromobility) can amortize much faster.

But yes, it has to fit. You can build simply and cheaply with gas without your own negative outlook on the future (of gas). At least as long as there are still gas heaters...