Single-family house planning with a granny flat - ~230m² - basement - gable roof

@all - Thank you first of all for the good suggestions! But please, this is not about the possible KfW funding. We will definitely comply with the legal requirements! And please, subsidy fraud is definitely not the case here, so please be careful with such statements. (not meant in a bad way). My point is that we are planning a house that can still be used in 10 years in such a way that the additional living space created by the son's move-out can be used sensibly. I think otherwise we have enough square meters for 2 people ;-)

But you will never recover 18-22TEUR in additional costs through the subsidy... economically, that is total nonsense.

I have a few questions: What is the purpose of the hallway? Why is the entrance with the two adjacent rooms not centered and the AZ located where the entrance is now? Where should the dining table be placed? How should the living room be furnished? How do you envision the bedroom situation if you always have to go through it to reach the bathroom? Where should the fireplace (stove) go? Where is the modern part? Sorry, the floor plan seems a bit old-fashioned to me – probably because of the large hallway... I do see an apartment planned, but not yet implemented. That will probably be a comfortable children's area for now :)

I also find the floor plan cramped and not exactly modern. But since you have a lot of space, you can afford to "clutter" it. If you like it that way...

What I really don't like is the master bathroom upstairs with the only access through the bedroom. In the requirements description, I read something about a playroom; so the mentioned son is still at a playing age. Little ones quite like to share the bathroom with their parents. That means: the son always has to walk through your bedroom. Personally, I wouldn't want to put up with that.

Overall: you have a lot of space and I'm sure there are much smarter ways to plan a house with a granny flat. Especially considering that the son is obviously still in playing age and doesn't yet need a very separate living area.

Without having a floor plan in mind: wouldn't it make more sense to plan a comfortable guest area in your half of the house, which is initially a children's area, i.e. a large room with a separate bathroom, fully integrated into your house? You can still plan a granny flat, but initially leave it in shell condition and use another room in the basement as a guest room. When the son is old enough to move into his own area (before he leaves the parental home completely; which never has to happen if he gets such a comfortable apartment; so I would consider that...), you can expand it as he likes. Until then, tastes and preferences will surely change. Or you use the granny flat as what it is: a rentable granny flat until the son is old enough to move in. So make a fixed-term rental agreement immediately. Advantage: it generates income that can be well used for financing. I don’t know how your apartment situation is; here in the Munich suburbs, you don’t have to worry that the granny flat will remain empty, you can rent it out immediately even with a fixed-term lease.

And: looks like it's self-designed. Right? For a house of this size and with the various requirements, I would definitely look for a good architect. The 5,000€ is certainly well spent.

: As already mentioned, this is not about the subsidy at all! We don't want 240 sqm for 2 people in old age but to rent out the 50 sqm. That’s why we are planning everything today and, if necessary, implementing it directly.

: Hey, those are many questions, but that was exactly the point of my post: to point out meaningfulness or improvements. Now, to your questions

What is the hallway for?: It's very large and designed open to let plenty of light into the house. The wall to the living room will not be built but made of glass.
Why is the entrance...?: The entrance should not be far from the double garage, because of a canopy.
Where should the dining table...?: The dining table should be opposite the kitchen.
How should the living room...?: The TV will go where the small window is or was planned. Left side.
Bathroom access?: You’re right, that’s far away... hmm good point.
Fireplace stove?: Not 100% decided yet, but probably on the wall where the stairs are.
Modern?: You can argue about modernity, but everything is very bright and open, thanks to the gallery and hallway.
Separate apartment...?: Correct, it is not yet a pure separate apartment but a spacious children’s area.

Modern?: One can argue about modernity, but everything is very bright and open, through the gallery and hall.

Who says? Now call it a city villa and conjure up a kitchen island out of thin air, and we won’t be able to close our mouths again.

We’ve also gone through all those considerations with children’s rooms, granny flats, yes no maybe, being flexible. First you look for the jack of all trades and then you make compromises later.

My tip: really find a capable planner. You have enough ideas, a list of requirements, and then find the right partner in the discussions.