Change requests as a tenant in a new building

Have you already tried talking to your landlord about the AGK and their purpose?

The AGK are simply a processing fee. Insofar as the builder "passes on", "forwards" or "transfers" the invoice for the surcharge, it is an effort for a businessman. One takes money, the other does not. I would also have the standard installed, then as a tenant exchange it for a better one and put the removed parts in the basement for moving out ;)

Don't understand the discussion. Obviously, the construction is purely standard and sufficient for the other parties, but not for you. As private individuals, we had to pay more for "nice" things that seemed necessary to us. And there are differences in the circle of acquaintances as well. Our developer paid his craftsmen fairly and we had fair extra charges. Some acquaintances had to pay the surcharges for the redesign you mentioned + partly horrendous extra charges. If I were you (if this hasn't happened) I would make sure you aren't going to have to pay for the dismantling of his special equipment. Then they will charge again.

By the way, you have the advantage of being able to claim this for tax purposes, private individuals building new homes do not.

Regarding your argument that you are not allowed to charge this or that, I cannot let that stand. I am privately insured and have had one or two experiences. They also like to charge 3.5 times or individually. When asked, I was sometimes told: We are allowed to do that, you are privately insured^^

I had rather expected experiences about what others KNOW about it or what can be done, or maybe someone has already experienced it themselves.

I had already provided that: with the experience that this is not an isolated case; and with the advice to only have pre-installed what is needed for assembly. And with the note that the withdrawal date as the point of depreciation (or letting the air conditioning belong to the landlord) can also be beneficial.