Property, house buying experiences, opinions?

Perhaps one point of differing understanding is that the OP assumes graduating at 30 is the norm. However, the average age after a bachelor's degree is 23 and after a master's 26 according to the Federal Statistical Office.

Yes, in recent years. But more than 10 years ago it was different; students graduated later (also according to the Federal Statistical Office).

Btw: my last post was also adjusted again. I mentioned that I am the original poster and why I had to register again. But I am now giving up on providing an explanation.

Basically, I don't understand this sentence. Is that the decisive criterion? Please calculate the additional investment versus the funding or interest rate. And whether you really save/use as much energy as it is calculated on paper? We built KfW55 and it is almost a zero-sum game. I recently wrote a bit about our house here. Maybe it will at least help you make the cost side more transparent?

Hi, we are also considering between KfW55 and KfW40 and in my calculations, I also come to a zero-sum game. Lower interest rates, but significantly higher costs. What I have not properly included in the calculation yet are the operating costs. Can you help me with that? How high are yours and maybe you know someone who built KfW40? Do they live self-sufficiently for several months, especially in summer, through a photovoltaic system plus battery?

However, the 26-year-old master's graduate does not start directly with a gross salary of 90,000 EUR. Often, loans still have to be repaid, a car, a larger apartment, furniture have to be acquired, etc. It is rather rare to find the job where one studied and continue to live in one's student flat or shared apartment. Apart from that, in many fields, the studies are not yet finished. You rarely see 26-year-old specialists, nor judges or prosecutors. In natural sciences, a doctorate is often required...