Which personal contribution is worthwhile in house construction?

Why should there actually be "no problems with the warranty" just because you don't connect it yourself? How is anyone who only places the cables supposed to understand the installation method? They can no longer assess it once the cables are plastered in or the screed is laid on top. Accordingly, it is not possible to lay out or size the cables correctly. Therefore, strictly speaking, it is not that simple.

Warranty or not, I would rather say that "stripping the wires" is the significantly more demanding task than later connecting the few wires. If you forget a cable or it is undersized, you might have some problems pulling this cable in afterwards. Therefore, most brainpower has to be invested here.

Warranty or not, I would rather say that "pulling wires" is the significantly more demanding task than later connecting the few wires.

So, the most demanding part is still the planning and the associated sizing. Well, equipping a distribution box and wiring it properly is also rather demanding

Pulling the wires itself is just work. You are even allowed to do it under the guidance/instruction of a knowledgeable person

Ok, then just the planning and making sure nothing is forgotten. You don’t have to be a genius to pull the cable yourself, of course...