Make an in-wall cable duct yourself?

Or how about something like this as a TV wall:

I can understand that you don't want such a TV wall, but rather that the TV should be mounted, even on a highboard. That is exactly how I have it and I am very happy with my solution.

According to DIN, a slot in the wall must not become that large.

Purely from practical experience, how was it done in the other rooms with heating, water, wastewater, ventilation, etc.?

Whether a 5-6cm wide gap in a wall a few meters long has a supporting effect... I can hardly imagine it at all

The floor plan looks exactly like that of friends who have a terraced house from Werner Wohnbau. There the electrician installed a flush-mounted duct in the wall (to the neighbors) and that was not a problem or was even done under the responsibility of the developer. Regardless: Could it also be problematic with regard to the warranty to do this now? If cracks appear somewhere on the wall that are supposed to be repaired later, the developer will always claim that you yourselves are to blame, right?

Thanks, we want to mount the TV as flat as possible on the wall if possible

We have a 75 inch TV

Such walls look quite okay with smaller TVs but with such a large one the wall would have to be quite big as well.

what solution do you have? also such a flush-mounted cable channel?

do you know the dimensions of the flush-mounted channel and how thick the wall to the neighbors is?

@Pacmansh do you know the dimensions of the flush-mounted duct and how thick the wall to the neighbors is?

if you are planning such a mess (15 cm thick exterior wall to the neighbor, chasing 6 cm deep) I would have the construction company give me written confirmation that the sound insulation is being adhered to. Otherwise, your neighbor might sue you or you might quickly get totally annoyed by him, his children, and the sound system...