Floor plan house with granny flat - improvement suggestions?

Well, the children are 17, 13, and 7. Apart from the little one, you can already expect a certain degree of pain tolerance from the other two, I think.

??? - the parents of Claudia-Maren were meant.

??? - it meant the parents of Claudia-Maren.

Huh? The point is that three children of primary school age would definitely cause chaos in the cloakroom, which Grandma and Grandpa wouldn’t be mentally able to handle. But at 17 and 13 years old, the two bigger kids will surely manage to hang up their jackets properly and throw their schoolbags into the cupboard.

Because this concerns the family itself, the shared hallway does not bother the parents. It is not ideal, but we have to be willing to compromise here.

aha, it doesn't bother the parents, but you… you would make the compromise. But actually not…?!

For that, one or two children's rooms would probably have to go into the attic.

No. The house remains approximately the same size because the space requirements do not change.

The student plans to stay in town after finishing studies (also has a job prospect).

But it is tedious to speculate about what will happen in 10-15 years.

It does not matter what will happen in 10-15 years. True. But as a planner, you must know whether the student will remain at Hotel Mama (for whatever reasons), or if he can be encouraged to find his own place. Sorry, but the crux here is a room that is somehow too much for a senior apartment and also does not belong to you.

To be honest, these are all relatively many ifs. If I were you, I would either plan a nice granny flat for the seniors and more space for your apartment than to hastily consider someone who might want to live somewhere completely different after their studies. And if that is the case, I have an idea that is quite simple. Put the seniors' apartment and the student's one-room apartment on the first floor, but in such a way that the apartment can also be well divided into a 4-room apartment, and then have the spacious apartment for yourselves downstairs. It is not barrier-free, but I know many people who still go to the first floor at an advanced age (even if with a stairlift). If that is possible, I would plan that as a suitable option. Because then you basically have a classic two-family house with identical floor plans on both floors, only with the possibility to separate one area. And such a house with two 4-room apartments can also be sold well and is not as nearly unsellable as your idea. Unfortunately, that's how it is.

Basically, the original poster wants 2 houses for the price of one. In my humble opinion, that is the crux of the issue where the project is currently failing.

Honestly, there are a lot of ifs in all of this. If I were in your position, I would either plan a nice granny flat for the seniors and more space for your own apartment instead of hastily considering someone who might want to live somewhere completely different after finishing their studies. And if that is indeed the case, I’ll suggest a very simple idea. On the 1st floor, accommodate the seniors’ apartment and the student’s one-room apartment, but so that the apartment can also easily be divided into a 4-room flat, and downstairs then have the spacious apartment for yourselves. It’s not barrier-free, but I know many people who still manage to get to the 1st floor in old age (even if only with a stairlift). If that is possible, then I would plan that as a suitable option. Because then you basically have a classic two-family house with identical floor plans on both floors, only with the possibility to separate one area.

So then, go ahead and make an approval-worthy proposal with 4 bedrooms, living room, kitchen, dining area, utility room, staircase, bathroom and guest WC + 2 parking spaces and terrace on this plot of land all on one floor. I’m curious.
Not to say it’s impossible. I just find it difficult.

Of course, it is really difficult, I admit that. Here is my suggestion. Yes, there is a room missing below, but you could sacrifice the kitchen there to make another room. Then you would only have 33 m2 of living/cooking space like above, but maybe that is just enough. Or two children share a room or the oldest moves upstairs to the student apartment and the student gets a tiny house in the garden. That's cool too, right? Of course, it is not meant seriously. Maybe you now have a new good way of thinking.