Building a house at 21 years old .. too young?

I by no means consider the draft absolutely good – but only relatively so against the background of the young builder, in the sense of a residential learning and planning training house or à la "my first Sony." At twenty-one, juvenile criminal law still applies to house planning. The house to come now only serves in my eyes as a first step on the way to homeownership. This allows the builder to first secure his first property and daily sharpen his senses through its use, understanding what could have been better planned. In five or perhaps eight years, he will then shed the caterpillar house and build a butterfly house. The more mainstream the hut is, the better it will sell again. Investing optimization energy now would largely be waste. A Pareto optimum in this situation is not only sufficient but even better.
I limit this assessment to the hard facts (walls); I do not take the painted-in furniture seriously and think that with a kitchen plan, this living-cooking-dining area can be planned in such detail that it fits within the framework of these walls. The bay window is expensive, mainly due to the consequences for the roof structure. But it is probably planned here to compensate for the stairs in the floor plan and is therefore not entirely dispensable. I would "smooth" it, i.e., shorten it by a quarter of a meter and instead bring the sides next to it forward into the same front line. The consequence would be a total of ten to twelve square meters more over both floors, but because of the then favorable roof structure, practically almost the same price.

I don't understand that. Why should it be a waste to optimize as best as possible? Building a house consumes so many resources and energy, I would definitely make sure to make the most out of it, without needing something new after just 8 years.

I have now read everything again and see that Daniel writes on page 6 in post 31 that the November appointment is set. I hardly believe that there will be much left to change in the floor plan of his prefabricated house. Daniel, maybe you will get back to us on this.

in November appointment

I don't find the design particularly exciting, but our house from the sixties is not strikingly beautiful either
You can still live well in it and adapt it if you don't like it, most things are possible. 140 square meters are enough to feel comfortable as a family.
(The children move out again at 21 anyway )

In any case, I wish:
Good luck and little rain.

Building a house consumes so many resources and energy, I would definitely make sure to get the best out of it, without having to replace it after just 8 years.

Pareto can be googled, I myself don't have a Bavarian diploma.

I was not concerned with Pareto (Thanks, I don’t need to google it), but rather with the fact that it is considered almost a given that after a short time you will build something new anyway.