Fiber optic connection is being installed - use existing multi-utility infrastructure?

That would be the question. At our place, Telekom, electricity, and sewage/water connections run from the start of the property to the house. Now power cables still need to be laid for the gate and the wicket gate. How is the garden landscaper (who digs; the electrician lays the cables) supposed to know where which cables have been laid? Sewage/water should not be the problem since it is laid deeper. But electricity and Telekom cables... Do you get a drawing showing where which cables have been laid?

I noted this down during the construction phase. And there should always be a warning tape (I can't recall the name right now, a yellow or red-white plastic tape) above electric cables in the ground at the required distance.

Yes, normally they take a somewhat thicker plastic band. The tradespeople here took photos and I think the electrical and cable guys also made drawings (but did not hand them out). In some cases, you can also obtain a cable inquiry somewhere. Although I don't know if it extends to private property. I also took photos.

I also took lots of photos right away back then when the cables were pulled into the house through the multiservice duct. When the fiber optic cable was installed later, I could directly show the guys the photos and say "That's where you need to dig, then you'll find the empty conduit." It was no problem at all. They were also glad they could go through the multiservice duct. It was less work for them.

It was the same for me. When laying the main power connection, I had a conduit laid parallel to the power cable in the trench. The fiber optic cable ran along the property boundary parallel to the power cable. This made it easy for the fiber optic crew. They could dig with a spade and were at my conduit within three minutes. This then led directly into the multi-utility entry point. The "blowing" of the cable took less than 5 minutes. Everyone was happy that it went so quickly and "without" complications. The subcontractor made some quick money there. With my neighbor, they actually cut through the main power cable. Things can go that way too... :oops:

I think the decision for us will be made when we are on site with the craftsmen. If, when suggesting to go through the multi-duct, the reactions from the craftsmen don’t feel like "no problem, we’ve done this on the last 20 houses too, we know what we’re doing," then I’ll drop it and let them drill/lay it as they do with all the other houses. What use is it to me if it’s not actually difficult to use and seal the multi-duct, but the craftsmen don’t do it often and therefore aren’t experienced? After all, I want a sealed entry into the house, and not end up winning in court later with the argument "the craftsmen should have known, so now they have to fix it."
Brief side note: [Glasfaserausbau] is being carried out by a local provider. [DG] started marketing in parallel three years ago and then withdrew (that’s a whole other story). I think the subcontractors doing the expansion probably don’t differ much in quality, but still I have the feeling that with such a small provider there isn’t much expertise in case of special requests or problems. Ultimately, neither of the two options (no matter what we decide on) is a catastrophe for me…

The tradespeople here took photos and I think the electrical and cable guys also made drawings (but did not hand them out). You can sometimes also get line information somewhere. Although I don’t know if that extends to private property.

At least here it does. We did that before the construction as well, electricity and water, because we had bought the place finished. At least with the water we then knew that they didn’t know where it was on our property ;). At the neighbor’s they did. They had to look for it.