Separate meter and electricity tariff for air-to-water heat pump sensible?

I would say that is not really good, but still quite standard. If one could have influenced that and halved the distances, maybe another 10% energy could have been saved.

+smaller heat pump. For us, this makes the difference between a 400V and a 230V device with the 7kW heat pump. Before anyone shouts that this would still be way too big: I KNOW! ;) Detailed discussion from here:

Regarding the topic, I never asked myself the question because I already have photovoltaics on the roof and want to use that for the heat pump as well. As far as I know, this only works straightforwardly with one meter.

Just for fun, I just fired up the comparison calculators. I only save 2 cents per kWh in the heat pump tariff here. Either I can't operate the calculators, have a kink in my head, or it would actually never be worth it here. Apparently, I did everything right with my planning.

However, I will ask the electrician to install a proforma meter for the heat pump so that the calculations become easier.

I would say that the cables were laid very tightly.

Worst/Easiest standard you can take. 15cm is already borderline.

That is a tight installation - 5cm! But it is also the triple amount of cables.

Hmm then I’m surprised that our construction supervisor approved the whole thing. I thought he was relatively competent since he also found some spots where the house building company had to make improvements.

Hmm then I'm surprised that our construction supervisor approved the whole thing.

No one is saying that it doesn't work or is wrong. In that respect, he can approve it without hesitation. But better is always the enemy of good.

It is also questionable whether it really saves anything. The heating cost savings (10% were mentioned, which would be €40 p.a. for us) are offset by investment costs for the pipe and labor, and the heating pump does not pump the fluid through the pipes for free either.