Main lines incorrectly installed

The correct reaction would have been to send the pictures and point out that all positions are offset by about 1 meter and that he should take a look at it soon in order to then take the necessary steps for correction. Then wish him a nice weekend and that would be good. If nothing happens by next Tuesday/Wednesday, or if suddenly masonry work starts, follow up.

Probably the connections will be reset, and the current ones then filled in. Whether this is correct will ultimately only be explained to you by an expert anyway (the site manager doesn’t listen to anything else anyway, if at all).

Measuring from the wrong points happens all the time. A classic example is when the raw floor suddenly becomes the finished floor and certain or all things sit 20 cm lower (e.g., toilet, windows, sockets) or then the height is not taken into account (e.g., stairs or even the ceiling)...
At a neighbor’s place, the house is offset by 2 meters because they misinterpreted the 2-meter recessed boundary stone (simply left out the recessed part...) during their own surveying instead of using a surveying office...

Hm... can it be any more unfriendly? He has to first get an idea of the current situation.

He has time for that, or rather he should have noticed the defect earlier. I saw it too, because I am busy with my construction.

I already had to point out twice to an employee of the general contractor that he should take a look at the scope of work.

Reminders by email should be avoided, I also don’t know any craftsman who voluntarily checks his inbox every day.

Why? I am building with a general contractor. Even on Sundays, the site manager reads the emails.

A reminder must also be given with a deadline, otherwise you are giving them unlimited time. Apart from that...

You are right. But I deliberately did not set a deadline. That would only be due upon completion of the house.

Are you building with a general contractor? Then they owe you the house that was planned... what happens in the meantime you have to partly endure. So if something happens on a Friday afternoon and the site manager wants to get an idea of the correctness of the work only next week, you cannot intervene, threaten or remind before he even had time to react. You can point out that something has caught your attention... he should take a look... but coming immediately with reminders is totally exaggerated.

It is good that you are careful, but please give the site manager or general contractor time to react.

I do give them time to react. I pointed out the defect. I also want to prevent bigger financial damage. On site, I have no authority over the craftsmen. The site manager dismissed my telephone notice offhandedly.

I won't say anything about that except: have fun building. I believe you either ruined your time with this email yourself or you are on a good path with your approach and opinion.

The correct reaction would have been to send the pictures and point out to him that all positions are offset by about 1 meter and that he should take a look at it soon to then take the necessary steps for correction. Then wish him a nice weekend and that would have been good.

I informed the site manager by phone on Friday.

13.11 Foundation and earthworks completed
14.11 Fine staking out by surveying office
15.11 Strip foundations of the house constructed
16.11 Basic pipelines laid
17.11 Floor slab and strip foundation of the garage constructed

I responded in writing by email on Saturday. Also to prevent further damage from simply continuing to build, with photos in the mail.

If nothing happens by next Tuesday/Wednesday, or if suddenly masonry work starts, ask about it.

I am also giving the general contractor time to respond.

Probably the connections will be newly set, and the current ones will then be backfilled. Whether this is correct will ultimately only be told to you by an expert (the site manager won’t listen to anything else (if at all))

Which expert? Do you mean they will hire an expert?
You apparently have little knowledge of DIN standards. DIN 1986 applies here.

I won't say anything except: have fun building. I think you either ruined your own time with this email or you are on a good path with your approach and opinion.

For your information, the site manager called today. He agreed with me. The basic lines are installed incorrectly. The heating and plumbing company has 14 days to present a solution.

Well, the plumber will be glad that the problem will now be resolved for him.

how can the error be properly corrected

Blasting, debris removal, new construction. I would definitely not agree to bending the pipes above the slab.

I hereby urge you to properly remedy the stated defects and to restore the contractually owed condition.

I find this wording correct, not rude or anything like that. What is missing is the deadline and possibly at the end the note "should you let the deadline pass without result, we reserve the right to have the defect remedied by a third party at your expense." A completely normal construction phrase for everything that cannot be resolved immediately after a verbal request.