Construction costs are currently skyrocketing

And one more note to the spiteful ones... your place and mine initially belong to significant parts of the bank ;) Always keep that in mind when making fun of people who build small houses or don't have a double garage.

And one more note to the spiteful ones... your and also my place initially belongs in essential parts to the bank

Nope. Your and our places belong exclusively to you and us. We are 100% owners and possessors. We merely have a loan agreement with the bank. Nothing more and nothing less. The bank can't do anything to the place as long as you pay your installments – as long as that’s the case, you can do whatever you want (setting the place on fire excepted ;-))
And even if you don't pay your installments, the bank won’t become owner of the place but will have it auctioned off.

Everything related to drinking water requires a registered master craftsman here in Berlin.

This was about renovations. You don't need a connection for that. And nobody notices what you do. Nobody cares about what you do yourself.

Nope. Your and our places belong exclusively to you and us. We are 100% owners and possessors. We merely have a loan agreement with the bank. Nothing more, nothing less. The bank can't do anything to the place as long as you pay your installments – for as long as that lasts, you can do whatever you want (except torching the place ;-))
And even if you don't pay your installments, the bank doesn't become the owner of the place but lets it be auctioned off.

That's hair-splitting blah.
As long as you and I transfer a sum X to someone so we’re allowed to live in the property, we are ultimately tenants. Because whether the place still has any value in 20 years, nobody knows.
This applies especially to those who have just newly built (like most here) and therefore own barely more than 20, maybe 30% of the house.

What belongs to me is what I can sell and pocket the proceeds 1 to 1.

So, we are now moving forward again with offers. Today the heating/heat pump;

Heat pump: €14,529 (Viessmann Vitocal 200-S E10)
Heat buffer storage: €977 (300 liters)
Heat pump accessories: €7,939 (base, covers, etc.)
Underfloor heating: €6,262 (two full floors completely laid out)
Heating piping: €3,564.52

In total, we had planned €5,000 more, so of course great if it comes out cheaper.

Are these gross or net prices?

Something current again...
Frost protection 32 + 56 per ton free on site €15.60