Floor plan improvement suggestions for a single-family house on a south-facing slope

I imagined it like this. Section West Finished floor about 60 cm lower

Ground floor gravel with at least 3 steps towards the east

The planning software suggests a total length of 2.4 m for 8 steps (see picture).

Planning software is a tool that should be mastered like a craftsman. If the software plays a trick on you, you should notice it.

Also, due to the shape, the entrance area is not so cramped,

The problem with the staircase is the location: you cut the house area into two parts, both of which are very narrow and therefore hardly any nice room layouts are possible…

Basically, we tried to plan as barrier-free as possible given the space conditions

… thus I actually did not implement the word “barrier-free” in this design at all. I am not starting with 1-meter-wide _barrier-free_ doors, but with all your narrow spots: if just a piece of furniture is standing somewhere, you can’t get past with a sports wheelchair or another walking aid (cane) without getting stuck. Bathroom on the ground floor: not accessible, office you have to leave backwards, collides with another resident who is either coming from the garage or from upstairs. Sofa: not reachable if someone is sitting at the dining table. Kitchen island that cannot be circled, pantry, also exit backwards here. For barrier-reduced living, a staircase with a lift can serve. This can also be a normally turned staircase. Important is: space… area… should be available everywhere so that you can move without bumping into corners or having to avoid another resident.

Besides the doors, the staircase counts for us as one of the biggest barriers in the house and therefore this should, if possible, have a straight walking surface.

The question is, what would be the alternative for the required space in the basement?

Repeated: larger floor area and then basement/tool replacement room. Required space is relative! If the budget does not allow it, you have to consider what is needed.

If you think the children's rooms are too narrow, what room ratio would you recommend? What minimum depth?

Unfortunately, there are no measurements attached - so it is hard to assess. Here are a few standard measurements that I use as common "new build" sizes: - Living room 4m x 4m - Children's room at least 3m depth on each side and at least 12sqm. - Dining area at least 3.5m depth and depending on the number of seats also 4m length.

I don't think the design is that bad at all. With a bit of pulling and pushing, one could probably manage to sort it out. What I do not see at all, however, is the monstrous basement extending to the garage with this budget. That is why the discussion about the floor plan is, in my opinion, obsolete.

The excerpt from the development plan shows more or less only your property, which is too little as a working basis for meaningful advice. First clarify your budget, and then go to an architect. By the way, the classification as a full storey has nothing to do with whether you convert the basement into living space - but exclusively with its protrusion from the (original) terrain.

From my point of view, there is nothing to improve here, since your planning skills work against the creation of a sufficiently suitable basis. An architect’s fee will cost you (for full support from service phase 1 to 8) less than a third of what you would have to bear in additional costs with self-planning, despite compromises with bottlenecks, still oversizes, terrain modeling costs, and the like. Being young does not mean you can really give full power permanently with your own work. Also, forget that a buddy will dig everything for a crate of beer on four Saturdays. Expect painfully stiff money, even on a moderate slope nothing is given away for free. It is better to go to the architect with a wish list than with concrete drawings - for such supposed "preliminary work" there is zero percent discount.

My reading tip as the planning of a fellow sufferer (also with a terrace on the basement overhang) would be

If the software plays a trick on you, you should notice it.

First, I would like to clarify that we are not professionals regarding the software but planned everything ourselves, so please forgive us such errors. Of course, we appreciate such hints.
However, I do not find the size that absurd at all. Of course, the software will use average values, i.e., the guy weighing 150 kg will feel a bit cramped, but that is acceptable to us. In everyday life, probably only 4-6 chairs will be used. It is still possible to set up all 8 chairs.

The problem with the staircase is the location: you cut the house area into two parts, both of which are very narrow, so hardly any nice room layouts are possible…

Where would be a better location for one of the mentioned staircase variants with the current configuration of basement, ground floor, attic?

You have to exit the office backwards, colliding with another resident who either comes from the garage or from above.

I think such situations are also frequently found in supposedly barrier-free buildings, as such an occurrence probability is rated as low.

I have indeed looked at the movement areas for barrier-free construction, but it should be clear that with the current floor area, the same movement areas cannot be applied as found in public buildings. Basically, I consider the rules for public buildings sensible, and certainly, it makes sense to transfer them to private residential buildings in certain areas, but in this regard, the available space in public buildings is naturally significantly larger. Unlike furniture, doors can only be changed with greater effort. Therefore, adapting to changed circumstances is considerably easier by changing the furniture. At least, that is our opinion.

If someone is in a wheelchair, they will not manage with the current kitchen layout anyway, since the worktops would be far too high. Therefore, we have marked a distance suitable for us, which is actually not that small either.
97.5 cm at the northern passage, 72 cm at the southern passage.
1.22 meters distance between the kitchen island and the kitchen unit in the west.

Unfortunately, there are no measurements - so it is difficult to assess. Here are some standard dimensions that I use as common "new build" measurements:
- Living room 4m x 4m
- Children's room at least 3m depth each side and at least 12 sqm.
- Dining area at least 3.50m depth and depending on seating also 4m length.

Dining area: 3.5m depth is given length 2.6m
Living room: approx. 3.5 m x 3.5 m is not that far from the specification either.

I have attached a picture with the dimensions of the children’s rooms; they are about 2.5m deep.

I don't think the design is so bad at all.

At least.

Monster-sized basement up to the garage with this budget.

Compromises can basically still be planned there, but completely without a basement, as already mentioned, is definitely not our goal.

2.50m as room depth is too little for a living space like a children's room. You can clearly notice that the wardrobe doors by the bed no longer open, let alone standing in front of them. Also always keep in mind that you are building a hut for 650K that doesn't even meet the usual standards. That's just ridiculous. As I said, one more tip: build bigger only with a basement and ground floor. That is in my opinion much nicer anyway. Together with the garage, you get a lot more usefully utilized space.