Who is responsible for the installation of the water connection?

We are currently having a bit of trouble with our general contractor regarding the water connection. Background: The utility room cannot be reached directly from the street because an existing building is in the way, so the general contractor planned the house entry for the water connection (electricity and other utilities come from the existing building) via a conduit that would run about 5 meters under the slab. It quickly became clear through a conversation with the utility provider that this is not feasible; it must be led directly into the house using a sleeve pipe (this should actually have been considered during the general contractor’s planning, right?). At that time, the wall section where the sleeve pipe is supposed to go was already built. The originally planned conduit was forgotten, by the way, and the price was refunded. Meanwhile, the interior plaster is done, as well as the external bituminous coating (the insulation is still missing). We have asked the general contractor to take care of installing the sleeve pipe; however, he refuses to do so, arguing that the connections are the client’s responsibility and that we should commission the company that did the shell construction on behalf of the general contractor, but this company does not want to carry it out. For warranty reasons, however, we want the installation of the sleeve pipe to be handled by the general contractor. The originally planned conduit also went through the general contractor. Now the question is, can the general contractor be legally forced to take care of the house entry? After all, it is an essential part of the ordered house... It is always amazing what little things people can argue about...

Hello, what exactly is stated in the contract and the [Baubeschreibung]? Because for us, the connections are explicitly our responsibility. So we commission the civil engineer for earthworks and core drilling as well as the municipal utilities, etc. for the laying of cables / pipes. Only from the handover points in the basement is the [GU] responsible again. Best regards

It is not stated that detailed, only that the house connections are applied for directly by the BH. However, the original variant was planned and billed by the GU, and now he does not want to know anything about it anymore...

You have a contract with the GU, in which he owes you a [Leerrohr]. Demand that he fulfills the contractually owed obligation (Leerrohr). He cannot simply change the contract unilaterally! If necessary, he will then be more willing to negotiate.