After a few hours of googling and forums, I am of the opinion that an air heat pump + photovoltaic system + battery storage is the most practical solution. For coziness, a stove is also planned in the living/dining area.
How do you come to that? You probably mean an air-water heat pump.
Yes, correct.
Advantages: no costs for gas connection and gas, no costs for the entire drilling process and permits, etc., efficiency increases due to power generation with storage, and you even get money for feeding into the grid. Cooling effect in the house in summer
Please don’t expect miracles in winter. You need power for heating, but the sun doesn’t shine then. Storage itself is not bad if it’s subsidized or, for example, if you have an e-car.
Photovoltaics alone almost always pays off – fill the roof completely.
You can forget about the cooling effect. Even with geothermal, it doesn’t get cold in the height of summer, not even really cool.
So currently we live in a house from the 60s or so, with basically no insulation, and after a hot summer day with over 30°C it’s similarly warm inside...
I don’t expect a constant 19°C but if the house would only warm up to 25°C it would already be a bit more comfortable :)
Disadvantages: higher initial costs compared to gas heating, increased electricity costs in winter when it’s really cold.
Higher initial costs? No.
Increased electricity costs in winter is true. But you also have increased gas costs in winter.
Actually, I am only unsure whether the increased electricity consumption cancels out the savings from not having gas? Are there other disadvantages I haven’t considered?
One thing you haven’t considered: What kind of house do you actually want to build? And your usage behavior. I can heat 120sqm KfW40 with 1,000€ electricity (windows wide open all the time and 25 degrees inside) or 300€ (only 21 degrees and proper ventilation).
The house is supposed to be at least KFW 55 level, is the difference to KfW40 only in the technology (solar, heat recovery) or also better insulation?
How much more expensive is a system with photovoltaic + battery approximately compared to a conventional gas heating?
How much more does a green car cost than a red one? Detach yourself from photovoltaics. It also makes sense with gas heating.
Does the stove support the heating in any way or does the heating always keep its temperature no matter how warm the room gets?
In new houses with underfloor heating, it is always equally warm. No matter how the heat is generated. Of course, a stove provides additional heating. But even then, you can install different variants. Heat storing or just "for fun."
Read quietly here in the forum.
Without a gas connection and unless you live in high mountains, I would take the heat pump. And if possible, then as geothermal. Always put photovoltaic on.
The gas connection costs 1330 gross up to 30m from the local supplier, but the house will be 100m away from the street, so I estimate it will be more expensive.
Here in the north, winters are rather mild; continuous subzero temperatures have been rare in recent years.
What is better with geothermal? In winter you don’t have to heat electrically, but otherwise?