Rain drainage with or without flushing shafts

The soil report states that drainage according to DIN 4095 is necessary if the basement is not built as a WW. The soil report was also provided to the general contractor in advance. The order confirmation also states that the soil report is to be incorporated into the structural analysis.

However, we now have a change order offer for €2,500 so that we can get our professional drainage. I wonder whether I now have to pay this, since the general contractor should have known from the soil report that the drainage must be built according to DIN.

Now we have also received an additional offer of €2500 to get our professional drainage. I wonder if I have to pay this now, when the general contractor should have known according to the soil report that the drainage must be built according to DIN standards.

Were the flushing shafts mentioned and listed in the first offer?

Were the flushing shafts mentioned and listed in the first offer?

No, only a drainage was mentioned. In my opinion, flushing shafts are part of a permanently functioning drainage. Furthermore, there are no documents regarding the planning (e.g. which slope).

No, only a drainage was mentioned. In my opinion, flushing shafts belong to a permanently functioning drainage. Furthermore, there are no documents about the planning (e.g. which slope).

Well, then you are involved with an additional €2500.

If I order a kitchen, I get an offer, and it will then be delivered at some point. And even if I believe that assembly is part of a kitchen delivery, I must not be surprised if the company refers to the offer, where assembly is not listed. Otherwise, everything is listed separately.

That is my opinion on this – even if it hurts.

Well, then you're in with an additional €2500.

If I order a kitchen, I get an offer, it will be delivered at some point.
And even if I believe that assembly is part of a kitchen delivery, I shouldn't be surprised if the contracting company refers to the offer where assembly is not listed.
Otherwise, everything else is listed separately.

That's my opinion on the matter – even if it hurts.

That would be one possible point of view. However, I also don't buy a new car that definitely won't pass the TÜV because the brakes are missing.

My offer states "Drainage". It has to be functional, but it won't be over the long term without flushing shafts.

My offer states "drainage". It must be functional, but in the long run it is not without flushing shafts.

That is your point of view

The car with missing brakes is a poorly chosen example.