A large space concept is looking for ideas

Impermissible causal connection!

- a connection that I would also express for myself with regard to your quote or had let be expressed, not as an necessarily logical consequence of your quote.

Ultimately, the room layout is a matter of taste. For example, I wouldn’t want to sleep in the [UG=EG] facing the street, but rather in the [OG] facing the garden. You can sleep there with the window wide open and don’t have to worry about people or creatures that might climb or crawl in.

But I would also keep it flexible:

[OG]: Bedroom, dressing room, bathroom, 2 rooms (children’s rooms or offices)
[EG]: Entrance with wardrobe, open-plan room, guest toilet
[UG]:
In the bright part: 2 rooms (children’s rooms or offices, one of which with kitchen preparation), bathroom, 2nd entrance
In the dark part: technical room, storage, pantry, utility room

If you already plan 2 entrances now, you can separate them better later. I would put the main entrance for guests, postman, etc. rather on the [EG].

not as a necessarily logical consequence of your quote.

I meant your quote. Stone or concrete basements do not necessarily or better exclude a timber frame panel house from the finished floor level. Besides, I consider it misguided to build an age-prepared house in your mid-30s or to include a granny flat when the budget is already questionable to comfortably meet your own wishes. I'm just too lazy to browse the development plan, but today's new development areas usually oppose your idea of three residential units later on.

you don’t have to worry about people or animals crawling/climbing in there

ahem....so you have no animals in the garden, but some in the basement, which is actually the ground floor? Terrible-.
For many years I had it exactly like that and found it wonderful; it was cool, quiet at night, animal-free (except for the occasional saber-toothed tiger in my little dreams). It’s a matter of design and personal preference. I have to take away the label "basement" from these rooms right from the start, because they are 100% above-ground living spaces with identical living qualities.

but rather on the upper floor towards the garden

....then another room would lose that connection to the garden; also, in summer I voluntarily went to the shadier bedroom anyway.

I was also referring to your quote. A stone or concrete cellar does not necessarily or better exclude a timber frame panel house above ground floor level.

Besides, I consider it misguided to build an age-adapted house in your mid-30s or, where the budget is already questionable for your own wishes, to also include a granny flat. I’m too lazy right now to browse through the development plan, but today's new development areas mostly oppose your idea of three residential units later on.

Okay, the legal situation is unfamiliar to me because it is not relevant to me. The common measures of "age adaptation" such as extra-wide doors etc. sound quite nice but in my experienced reality have mostly appeared quite differently. My idea of "age adaptation" would rather be the thought of parting with an inappropriate property again. My idea for this thread lies especially in flexibility for changed family circumstances, whatever they may be; I would by no means have the parents’ retirement phase in mind. Otherwise, one would rather recommend a building plot near a pharmacy, a nursing home or a cemetery—. Sorry, I had it like that; a school above, a cemetery a little bit next door. So pleasantly quiet apart from 1-2 times a month—. My mother was happy about this easily accessible proximity because she could go to the grave daily and could even see it from the dining table. I would never have thought that such a circumstance could also have a positive effect. From that perspective……who knows what will be...

ahem.... so you don’t have any animals in the garden, but some in the basement, which is actually the ground floor?

I slept on the ground floor for a few years and did indeed have visits from hedgehogs, neighbor’s cats, and quite a bit of crawling critters when the window was open. When my husband wasn’t home, I didn’t dare sleep with the window open – anyone could have just jumped over the fence and come in. So I really had bad experiences.

A bedroom facing northeast would be ideal, wouldn’t it? Children’s room / office facing south, since the view there seems unobstructed? Obviously, there is greenery on two sides – wonderful.