Experiences with brine heat pump

You mean screed heating? That depends on all sorts of things – outside temperature, mass of the screed, type, insulation, heating curve/time, etc. For us, it was about 2300 kWh of HEAT. It wasn’t very cold outside, I think around 10C. Depending on the COP, which is only medium of course, the warmer, so about 550 kWh of electricity, or more, or less, depending on the construction project, with a heat pump.

Exactly.
For us, the construction phase would be in summer, so it will probably be warmer than 15°C then. Okay, as a guideline I will assume 550kWh.
We were told that costs of 1400-2200 EUR are likely to come up.

Can the heat pump do that at all? For these amounts of energy, the heat pump is generally not designed. And something like 1000-1500 euros can definitely be accurate if it runs via a separate [Durchlauferhitzer].

We already had this question somewhere in a similar form yesterday, except for the starting up it works. A brine heat pump can keep a house at temperature without an electric heater even at -15°, so why shouldn't it be able to heat up from 15°C to 30° (smaller difference!)

We were told that for the drying heat-up we should rather use the heating element... that suits us quite well since the borehole is not finished yet. We should expect costs of about €600. I can report later what it actually ended up costing.

It’s not entirely clear to me whether warm outside temperatures are really good – I would rather say no. Better to have it nice and cold outside so that cold air is let in, heated and saturated with water, and then vented out so that you have new cold air again. The components don’t cool down that quickly. That would be my understanding.

I have heard that the weather machines are fully booked. Otherwise, you are right, cold (preferably dry) air is best for drying. Just not too fast please with screed, it is supposed to set, not dry, and for that it needs some moisture for a while.