Delivery and Payment of Prefabricated House - What Is Accepted?

If tiling work, exterior plastering, and sanitary fixtures are still outstanding, there can be no final acceptance and certainly no final payment. For a final acceptance, all contractually owed services must have been rendered. Is this a contract from 2017 or already one according to current construction law?

It is a current contract from 2018

How high is the agreed final installment there, ?

15% of the house price is agreed as the final installment

then the contract is apparently okay so far. Be sure to also proceed according to the contract. If a contractor insists on acceptance in order to receive the payment installment, all alarm bells should always ring!

The problem is resolved and the contract will be followed. So no premature acceptance