Construction costs are currently skyrocketing

For fun, one could also calculate when the 25 kWh/m²/a will pay off, for which one has invested a high five-figure, possibly even a six-figure amount compared to a "normal" house (which is just still permissible according to [GEG2020]) :D

Here are current net prices (Southwest) in the earthworks sector:
Set up construction site €650.00
Dispose of excavated soil at landfill €24 per t
Create subgrade with 30cm gravel and compaction €28 per t
Gravel driveway €28 per t
Install mixed inspection chamber €2,700
Lay wastewater pipes per meter €95
Lay rainwater pipes per meter €90
Gravel for backfilling work areas €20 per t

I can't imagine that the screed layers manage not to step on the heating pipes when laying cement screed with a laying distance of 10cm (or less)...

The laying distances don't matter there. They walk on it like a farmer in the field. Even with a 30cm laying distance, they trample on it diligently.

But normally that's not a problem. The pipe can easily withstand it. It already does during installation when you staple rooms with 5 cm. No one pays attention to where they step.

It doesn't matter as long as everything has been fastened to the [tackerplatte].

Installation distances don’t matter there. They walk all over it like a farmer in the field. Even with a 30cm installation distance, people stomp on it diligently.

But usually, it doesn’t matter. The pipe can handle it without any problems. It already does while laying it, if you sometimes fasten rooms with 5 cm. No one pays attention to where they step.

Well... with a 30cm installation distance, the probability and number of hits is significantly lower than with 5cm spacing. Usually, that may be irrelevant, yes. But it’s an additional potential source of error that one can certainly mention, right? Then he just steps on it awkwardly or drops something and boom... prior damage that eventually leads to leakage…

Especially since we have already calculated that the 4,000 EUR extra cost is never saved during the lifetime… and for that, twice as much pipe under the screed that can break? And twice as many controllers that can give up the ghost?

These are all just snapshots. What did not pay off at all during a lifetime 10 years ago. Since electricity is guaranteed to move in only one direction over the next years/decades, various measures will indeed be worthwhile. Added to this is the uncertainty regarding political decisions, which already talks about rationing and capping [der Strom Preise] up to a certain quota. The reduced consumption will likely have an impact on profitability as well.