Floor plan / planning of a single-family house with a granny flat on the upper floor

Primarily, we try to get a functional floor plan on the ground floor and then plan the upper floor. My father is really very frugal

Do I really have to recite the mantra of the gravity of floor planning every week like the rosary? The urgent advice to start with the "second" level basically applies – also, if this like here should be the level of the resident with "lighter" wish-weight. In your case, however, there is a special feature that the "second" floor is supposed to be the smaller one. It follows that if the upper floor is to become a full story, practically rooms for common or the needs of the ground floor residents must be placed there. With the utility room this only works to a limited extent, but well with the housekeeping room, storage room or the like.

But to be honest: I assumed the worst and expected you to bring me back down to earth again and that I would discard the current floor plan

Oh dear, you don’t scold once, and it’s already misunderstood as praise. I am further away from finding your latest ground floor good or even just good enough than the Marlboro man would be to get a cigarette. I have merely, as it is only half a house after all, considered it factually not yet worthy of evaluation. The ground of facts is hard and here, especially, nothing for "wimps," as instructor Schmidt would say: I consider this concept, basically only to transform the status quo (the band of the same name pleased me quite a bit back then) a poorly viable pipe dream. I am sorry if I may have irritated you by nonetheless answering the principle question of the most suitable roof. That the squaring of the circle has an empty set of solutions is of course an unproven thesis and its success not completely excluded – but a layperson at least needs a fairy who is not an only child for that.

About the therapy
Father has been doing occupational and physical therapy at home for over 6 years - does not use a room.
My girlfriend usually goes to sports with other MS patients depending on her condition and her therapies. The car has been modified.
About the house: I would plan it so big that the wheelchair can go everywhere, the rest as needed. It should become a home to feel comfortable in and not everywhere a reminder of what might not be possible at some point.
And yes, you need space. With crutches, you can no longer walk sideways between the chair and the wall.

Planning a stairlift is not a mistake, your father is not getting younger either.

Hello Oimelwutz, you could look for a video from SHK-TV on YouTube. The title is "Viega: Höhenverstellbares WC-Element Eco plus" There you can also see the glass plate with height adjustment of the washbasin very well. All kinds of washbasins can be attached there. It just must not be too heavy. It works with a gas spring, like on an office chair. I find the system very stylish. It is not immediately obvious that it is a special product but rather looks like a stylish splash guard behind the washbasin. Next to it, discreetly, the button for adjusting the height.

Hello ,
thank you very much for the tip. The things make a good impression and really look great.
I noted them down immediately

Otherwise, not much has happened with us. We are still looking for a suitable partner for our project.
In mid-October we have another appointment with another construction company and with a building consultant.
In addition, we will contact two architects this week.

Meanwhile, I am of the opinion that without an architect we will probably not create an ideal floor plan. I would even prefer it if he would accompany us throughout the entire construction period.

I am curious to see how and in which constellation things will continue.

In the meantime, I am of the opinion that we will probably not create an ideal floor plan without an architect. Ideally, I would even prefer if he accompanied us throughout the entire construction period.

That is exactly the classic job of an architect, and you definitely need one: with a general contractor's drafting slave, you won't get any resistance if you put nonsense on the wish list (as long as it is approvable and you can and want to pay for it). A good architect is well worth the cost.

Is there an MS group with you? Maybe someone can recommend an architect who has accompanied a conversion or new build. Almost everyone can manage senior-friendly or similar, with the standard for wheelchairs it gets trickier. GCs who should be able to do it are Wir-Leben-Haus and Wolf Haus (Gefäll).