New single-family house on sloping plot

This is what the development plan says:

Hm... Your house has to be placed far back. There is practically no north garden, and also little to the west. So your main garden is in the south. And you want to connect it to the house via a garage?

In the photos, the terrain doesn’t look so steep either, as if the slope over the length of the house reaches the height of one floor. That would mean that either your ground floor extends significantly beyond the terrain (also at the back), or your basement lies significantly lower than the original terrain, meaning that a "furrow" would have to be dug into the ground for the driveway to the garage...

From the perspective of the development plan and the property photo, I would spontaneously tend to attach the living rooms directly to the south garden. That would mean no garage in the house. Instead, I would simply make a driveway all the way to the house, so you don’t have to carry everything a long way. We always park outside in front of the house with two very small children and except for getting caught by a few drops of rain now and then and having to scrape ice 2–3 times a year, nothing bad has happened to us because of it...

You could also leave out the garage at first (if the budget is tight) and build it later, when you are sure you need it and have the financial means.

If your garden were behind the house or on the side, I would also plan like that with the garage in the basement. But given the house position, I would think about it carefully.

Addition: I would then place the driveway on the east side, as well as the house entrance. This keeps the west side free in case a garage needs to be added later, and you would still have the driveway right up to the house.

In the opinion of the development plan and the property photo, I would spontaneously tend to connect the living rooms directly to the south garden. That would mean no garage inside the house.

I’m completely with you. Under these conditions, the garage has no place inside the house.
Basement: Entrance, utility room, guest WC, living, dining, kitchen
Ground floor: Parents, parents’ bathroom, children, children’s bathroom
Upper floor: Play, work

The planner considers only this orientation to be sensible;

Me too, keyword photovoltaic.

Having the terrace facing south does make sense.

With such a large plot, a roof terrace makes no sense at all, unless you don’t know what to do with your money.

Garages are generally in the front. The neighbor on the right has integrated them into the house. This solution is simply more practical and nicer

... and more expensive and energetically problematic

No, it is primarily practical because groceries and small children don’t have to be carried through the garden first.

IMHO often overrated. When shopping, you also don’t always park directly at the entrance.

Can you explain to me how the two-storyness is defined here? I read here 50cm knee wall, two-story as ground floor + attic. For me, that would already be a contradiction in itself. Is that just an outdated formulation and they actually mean single-story? Maybe now would be a good time for more information about the slope's steepness. You see, opinions differ on whether a complete story of 10 to 11m depth actually comes out here. I rather think yes, with a bit of filling here and digging there, but maybe it is also too little?

Sorry, that's all there is! But I also know that I am an absolute, complete construction layperson. I think the approach to the architect is the right one for now.

Please talk about the costs at the very first appointment and think beforehand about which phases you want to hire him for. Maybe just 1-4 for now. Also ask him about a flat fee. You don't want nasty surprises later. The architect will want to see money after a (maybe) free initial consultation.

Is that simply an outdated term and does it actually mean single-story?

No, with dormers and/or cross gables, the boundary to a full story can be reached.