Double costs for the bathroom / who has to pay?

Hello!

First, a few pieces of information:
My girlfriend and I bought a semi-detached house near Bremen at the beginning of last year. It was a new building that was still in the shell stage.

So, in terms of planning, we still had all possibilities.
We received a list of the craftsmen who work with the seller from our seller.
Our purchase contract includes a basic equipment for the bathroom, which we completely changed. However, we could not choose the executing craftsman. So, we only had to bear the costs that exceeded the seller’s standard. Unfortunately, during the construction, two (!) of the bathroom installers went bankrupt, although we had already paid almost €6,000 in advance.
Almost nothing happened in the bathroom, which is why the handover date could not be met. The developer therefore had to find a new craftsman for the bathroom and pay again. Overall, the bathroom was therefore practically paid for twice.
Now the developer is charging us these costs.

Now the question: Who is obliged to bear these costs? Because we personally could not choose the craftsmen and the developer naturally accepted the cheapest offers possible.
Is it legal for him to charge us this second invoice? Contractually, only the standard was secured, but not our changes.

I am unfortunately a bit desperate. I hope my problem is understood.
I am grateful for all hints and comments.

Thanks in advance!

Best regards
Tim

To whom did you make the advance payments? Directly to the plumbing company or to the developer?

To the plumbing company directly.

I believe that this is not a developer, right? With this one, there is a fixed price that does not change except through special requests, and payments are not made directly to trades.

So, only a corresponding lawyer can really tell you this in a legally secure way! It is a question of the exact contractual constellation, but the fact that you paid the plumber yourself does not sound very good. Because then he would be your contracting party who has gone bankrupt, and the contract was continued by a new one, which also has to be paid.

BUT to really assess this, you need a lawyer who looks at the contract! What exactly did you buy and in what capacity does the seller appear?

I don't think this is about a real estate developer, right? With one of those, there's a fixed price that only changes due to special requests, and they don't pay the trades directly.

It was about a real estate developer. We have a fixed price for the entire house. This fixed price included a standard for the bathroom. All special requests had to be paid separately to the trade after calculating the costs for the standard with the developer. Super complicated. I'm really just annoyed about it...