Thanks already for your hints. However, for the further course of the discussion, I still have to set the facts straight once again.
Personally, I do not work a 60-hour week for my money. This statement referred to the lawyer salaries in Frankfurt. With 42 hours per week, it is 4000€ net.
Regarding the statements about the outdoor area, my consideration is the following: Of course, I do not want to use inferior materials or have a standard that significantly deviates from the main building. But the fact is that we are still very young and therefore can definitely cope with the fact that not everything is as we might wish when we move in (it was no different at my parents’ 30 years ago). Therefore, for me it is quite an option to do only the necessary in the garden at first and then, in the next years, maybe also with some own labor (which I still have with my 42-hour week), to create the desired picture. Furthermore, we expect a family income of over 7k (without special payments) from the medium term (from the end of 2019) if the exam works out. And that also if my wife should only work 60% and a child is there.
We simply want to create the conditions to live in a few years the way we have always wished. And if that means living without garden sprinklers or pool for 2-3 years, that is absolutely no problem. The same applies to furniture. For me, the basement would be much more important there.
The only thing we really do not want to compromise on is the kitchen because we like to cook and invite friends. There we will certainly invest 25k upwards.
What is also clear is that we will not build anything just to change it later. If we save, then by leaving out something that can later be retrofitted easily and without considerable additional effort. Maybe one or the other has ideas where else such savings potential might be.