Gas with solar thermal? Or heat pump with photovoltaics? Consultation

Hello dear community, unfortunately, my appointment for the energy consultation planned for tomorrow will not take place due to personal reasons and I therefore cannot report. However, after all the comments I have read in this thread, a preliminary offer now created, and after conversations with two colleagues who are already building and facing exactly the same problem, I must admit, which even surprises me, that I will probably tend towards gas condensing technology and solar thermal with the option to upgrade this system in the future with a photovoltaic system or geothermal heat pump.

Install the solar thermal system, [Ggf Sat Anlage] and other penetrations so that they do not obstruct or cast shadows on a photovoltaic system.

I have lost track in the whole thread whether you have planned a controlled residential ventilation system. If yes, I would omit the solar thermal system. It is actually no longer necessary if properly implemented.

Can something like a brine-to-water heat pump be retrofitted that easily? How close must such a borehole be to the house?

Very interesting discussion, thank you very much! (even though I had to smile because of the complicated description of a split air conditioner) since I am still at the very beginning of my planning and research.. One question also arises for me in the context of this discussion: to what extent does the decision today influence my modernization options in the future? If I want to modernize the heating in 15 or 20 years, am I limiting myself by the decision between today's options? Or does it not matter?

even though I had to smile because of the complicated description of a split air conditioner

Yes, that was the intention besides the clarification. Because that's exactly what general contractors, building contractors, and other home construction companies do. They describe the technology to interested parties as complicated as possible and present it as the ultimate.

In fact, every heat pump is basically a split air conditioner, is sold as such, and it often even says so directly on the device. It's also funny to read or see how heat pump buyers then vehemently oppose split air conditioners to the death. Like: "Something like that won't come into my house!" "I'm for environmental protection" meanwhile, a split air conditioner is used for heating, only usually water is heated with it and not the air directly.

At least it has slowly sunk in people's minds that an air-to-air heat pump is indeed a genuine split air conditioner and suboptimal for heating houses in our latitudes.

May I explain the reasons why we are planning a KfW40+ house with a ground-source heat pump, underfloor heating, controlled residential ventilation, photovoltaic system + battery storage?

"Of course," ecology is also a concern. I hope building sustainably like this is the right way. Lots of wood instead of lots of concrete/stone (The production of cement releases huge amounts of CO2)

Children + grandchildren -> responsibility

Nevertheless, we also have to think economically, the money is there, but unfortunately not unlimited :-/

With extras like controlled residential ventilation, the living climate is hopefully more pleasant than in a stone building without controlled residential ventilation. Unfortunately, I have no personal experience with all alternative building methods, only "hearsay."

A better-insulated building will be correspondingly more expensive, but at the moment KfW40+ is very well subsidized, additionally Progress NRW and BAFA. (By the way, it is hardly possible to achieve KfW40+ with massive stone construction at reasonable wall thicknesses)

My bet: In the medium term in 10 – 15, max. 20 years, lower total costs (construction + operation) than "conventionally" built.

Fossil energies are finite; long-term use will lead to increasing costs.
A heat pump in combination with photovoltaic (as much photovoltaic as possible!) + battery enable maximum self-consumption of the self-generated electricity. Ideally, in the medium term, an all-electric battery vehicle as well…

This results in long-term low operating costs (the photovoltaic system essentially pays for itself, if you don’t believe it just calculate with Photovoltaic SOL)

However, with all technical systems, no one is safe about what will happen in the future that could positively or negatively affect efficiency (looking into a crystal ball)

And finding a suitable partner who can plan and build this might be difficult…

Besides, I cannot and will not recommend to anyone how to build in any form.
This is only meant to inspire thinking in other directions as well.
It can’t hurt – can it?