ᐅ Incorrect planning of ceiling boxes in precast concrete slabs

Hello everyone,
I am currently having my house built by a developer (145m² (1,560 sq ft) of living space across 2 full floors plus a basement, exposed roof structure, controlled mechanical ventilation) and I have a small issue where I would really appreciate some advice:

For the ceiling boxes (LED spotlights, occupancy sensors, speakers, standard electrical boxes) in the basement and ground floor, I provided the layout, complete with all measurements and a truly (sorry) foolproof legend. Everything was also drawn to scale. These were then transferred to the ceiling plan and sent to me on a regular weekday afternoon (3 p.m.) for approval, with the expectation that I would approve them that same afternoon.

I immediately noticed two placement errors in the boxes because they were obviously drawn completely wrong in the room, even though all the other boxes are aligned. However, in the short time, I unfortunately overlooked that two incorrect boxes were also shown in the plan, even though I had specified the manufacturer including the article number. I only realized this during the on-site ceiling inspection, so now core drilling will probably be necessary.

The question here is: who covers the costs? The developer claims that since I did not correct the error and approved the plan, the fault lies with me. This is obviously true, but I do wonder why I am paying the premium for a developer, taking the stress of creating a painstakingly accurate millimeter-precise plan myself, only for such careless mistakes to occur later during the simple transfer of measurements and boxes (there are only 3 different types plus speaker enclosures...) and then I am expected to foot the bill for fixing them.

What is your opinion?
Best regards,
Tranceport

Approved is approved; you will probably have to cover the costs yourself.

Why choose a worry-free build with a developer?

That was a special service, which was certainly not included in the scope of work. Otherwise, nothing would have needed your approval. In that sense, he cannot be held responsible for

errors. And neither can you. There will always be costs in life that could have been avoided. That’s just how it is and not a big deal.

I bet every homeowner has some socket, ceiling outlet, or something else where the purpose was somehow overlooked.

First of all, a correction: this is not a property developer, but a turnkey solid house, and the plot belongs to us (I learned that in another discussion).
But why a special service? How does it work on other construction sites? Somehow the builder must be informed about how the client wants the ceiling, right? And my specifications were 100% correct and clear (position x y: Kaiser halox o Art. 1290-40).

Yes, I almost expected that you meant a GÜ. However, it doesn’t matter here: You have specified some extras. Normally, the scope of work most likely only includes a central outlet, which is placed in the middle of the room.

Okay, understood. Thank you all for your answers!