Ground floor plan city villa 230 sqm

We already have a BU, but we want a concrete and viable idea

since the planning is still open in all directions.

I don’t see that here, nor would I if I were BU. Write the BU a room program and then see what they can conjure up with their possibilities. But if you with tunnel vision withhold information, for example that you absolutely want a FW, but it should only be for the family, then something gets distorted. This also applies to the budget!!!

If I were you, I would give up on the [Einliegerwohnung] because I consider the property too small to accommodate a [Einliegerwohnung] sensibly. You are restricting yourself too much on the ground floor.

I had no idea before how cramped living in a large house can be.
EG: The "open-plan living area" has the charm of a narrow semi-detached house. This is not bad in itself but somehow a shame to make so little use of the possibilities when you already spend so much more on your house. The ground-floor granny flat takes up a prominent amount of light and space on the ground floor. Even though, unlike , I can very well understand not wanting to have parental visitors in the house for too long and I don't know what holiday rental income "tempts" you - the sacrifice would be too great for me. With a slightly different building shape, the granny flat could certainly be better separated.
OG: The children get a living space hardly larger than the parents' dressing room; in return, there is a "ballroom" in the bathroom and the attempt to fit too many rooms in.
I would never build like this - but everyone is different.

The terrace (not the garage @11ant …, I am quite sure because of my own house, but not 100%… and there are development plans that explicitly change something there beyond what the state building code allows) belongs in Floor Area Ratio I.

I am also not 100% sure – and unfortunately "our" expert has been driven away – whether the garage would not also belong in Floor Area Ratio I, and only its driveway in Floor Area Ratio II. Above all, I have doubts here specifically (in this case of the floor area ratio given not as a decimal but as an absolute figure) whether there is even a bonus floor area ratio ;-) for ancillary structures.

Since these are only our plans so far, they certainly won’t be any better.

Without the (experience-based) suspicion, I wouldn’t have suggested you show them. Especially lay planners blessed with little talent often have an astonishingly sure "touch" for erasing the spots where even a blind hen found a grain when attempting "improvements." Then undoing "improvements" is easily in danger of becoming a miraculous cure. It would be worth a try, though (?)

We already have a building permit but want to approach this with a concrete and viable idea – and for this I am glad for input from you, because you have the experience, I don't – so that we can save a few planning rounds.

And do you really believe that with the support of a forum you are sufficiently able to put a draftsman on a creative course? – for the builder, the idea of ripping more money out of your pocket for a maximum size hut is without a doubt viable. Whether you fail to cook up the recipe from for a self-built sauna doesn’t matter :)

Above all, I have concrete doubts here (in this case about the absolutley specified floor area ratio, not the decimal one) whether there is even a bonus floor area ratio ;-) for ancillary facilities.

That, however, I also think. Be that as it may: putting the entire budget optimization into the size, i.e. inflating it, is the wrong approach anyway.

Be that as it may: putting the entire budget optimization into size, that is, inflating it, is the wrong way anyway.

Only for the OP. The contractor is happy when the customer thinks like a multi-story building client and fills the building window up to the edge of the pool with square meters :)