I also cannot understand why BG Bau is viewed so positively here. For example, if you register the father-in-law as a construction helper and then feel safe that he is insured, his help can be classified as a favor if something happens, and you do not see any benefits from BG Bau. This has been decided repeatedly by courts, and the crucial point was that the relatives helped a lot in terms of time but did so without payment. Therefore, you would have to take out accident insurance anyway for the property owners and the father-in-law, and there are some that include all construction helpers at once; that way, you are better off.