Heating system new construction (heat pump + stove + solar)

How high is the water temperature coming from the brine? 10 degrees?

So our office is cooled by well water. The cooling runs 24 hours, but uses relatively little electricity.

That's always the problem. But if you want passive cooling in the summer, you won't get far with oil anyway. Then only air conditioning or a heat pump with cooling function helps. And then photovoltaics are useful again.

Whether oil works without solar (in the sense of being allowed)... you have to ask someone who knows about it.

But as often: no matter what it will be, calculate, calculate, calculate.

You write that gas would be your preference? Then just take a liquefied gas tank and you can install a gas boiler. It doesn't get any easier than that.

Then oil can be used right away. For me, oil and liquefied petroleum gas have absolutely no place in new buildings anymore.

So anyone who has had liquid gas once does not want it again. Expensive, complicated,....

Otherwise, I am of the opinion that gas is the right energy source in new buildings. The madness of wanting to do everything with electricity is a joke in Germany.

Then you might as well use oil. Oil and liquefied gas have absolutely no place in new builds for me.

You inevitably need a basement for oil, gas can be stored much more space-savingly in the garden.
Can you briefly explain to me why specifically liquefied gas has no place in new builds anymore?

If there simply is no gas network available, the alternatives are scarce. And not everyone likes heat pumps.