Mold in old buildings, wrong windows, clarify regulation 2004

Hello, I moved into a renovated old apartment in 2005 and soon had mold and moisture problems on the exterior walls. Meanwhile, the matter has escalated into a legal dispute. I am of the opinion that the cause is the walls being too cold because they do not match the new windows. I have the following question: The apartment was renovated in autumn 2004. All windows were replaced with new insulating windows. The walls remained unchanged (28 cm wall thickness - no insulation). The apartment was expanded by a former garage. As a result, the living space increased from 79 to 97 sqm. Were there laws and regulations at the end of 2004 that apparently were not followed, and if so, which ones?

Yes, fine, but unfortunately the information is not sufficient for a remote diagnosis. However, 28 cm wall thickness is quite thin if there is no insulation and new windows have been installed (even if it was already in 2004). But as I said, you can’t just say that so easily; you would really have to examine the matter on site. Whether laws or regulations have not been followed is also not so easy to answer, because it is again unclear what you are referring to [Wohnflächenverordnung], [Energieeinsparverordnung], building permit? If there is a legal dispute, an independent evidence procedure will be ordered sooner or later.

Thank you for the response, I mean the [Energieeinsparverordnung]. If you convert a garage into living space, doesn't the newly gained living space have to be designed according to the current [Energieeinsparverordnung]?