Heating type for new construction - Which is the best?

He therefore recommends getting used to this ugly outdoor unit of the heat pump.

Even though you should primarily not choose the air-to-water heat pump based on appearance, but rather on heating load, take a look at Ochsner or Alpha Innotec; they offer units that I at least find acceptable for aesthetic reasons... The controlling factor should be the heating load, determined with the already mentioned heating load calculation.

Heat load calculation!!

A vicious circle. Unfortunately, this only comes after the contract for work is signed, because only then does service phase 4 begin, where the heat demand calculation is carried out. And anything that is not included in the contract beforehand and is changed must be expected to be costly to have to buy later.

Can't you commission them separately and then provide them later?

For me, the drilling costs 6700 euros, for a 5KW heater.

So, I just called and requested a price quote. Drilling for 8kW extraction power will cost only 12,000-15,000 EUR... you really have very builder-friendly conditions there. Here with us, 100m is the limit at the latest, sometimes even 60m. Anything deeper than 100m requires a special permit from the mining authority, which involves considerable effort - according to the information. So it will probably be an air-to-water heat pump after all...

I am not allowed to go deeper than 100 m either. It is partly calculated on a guess. The construction contractor said the drilling company did it as a flat rate. How long it takes, etc., is the company's risk. That was how it was calculated in another offer as well, but already with 9000 euros. The company that is drilling now has already drilled on site before, maybe some experience values.

Can't you commission them separately and then make them available later?

I probably won't have any other choice, because otherwise I won't be able to negotiate anything once the contract for work is signed. Then every change will be extremely expensive.