Newly built single-family house approx. 170m² city villa

You don't get many supplies in. Draw your building services, washing machine, dryer, laundry collector, small drying rack, basin for hand washing, cabinet for cleaning agents, there's not much storage space left.

I have also created the original site plan here with the contour lines entered.

Slope: Terrain currently drops about 2.80m from south to north. However, it will be leveled as part of the earthworks carried out by oneself and brought to about 1m above street level

The question is also whether this is even allowed. There are often height specifications related to street level in the development plan.

If you have to do without, which details/upgrades
It is already kept minimalistic from our point of view. We reduced from 190 to these 175m².

I am always amazed... you are two people, and find 170m² minimalistic? Ok, you want to start a family, you can tell from that. And then each child gets 13m²? Even the children's rooms in my (actually minimalistic) 100m² house have that...
Especially since it hints between the lines that you want to watch the price anyway.
Of course, it’s absolutely up to you to live in this house size even as two people, I just do not find the term minimalistic fitting. I have other associations with that...

The question is also whether that is even allowed. There are often height specifications related to street level in the development plan.

It is allowed. We are allowed to build 1m above street level at the top edge of the finished floor. I have taken that into account in my planning. Since the street is still in the preliminary stage of construction, I have fixed the top edge of the finished floor at +1.15m from the current street level.

I am always amazed now and then... you are two people, and you find 170m² minimalist? Ok, you want to start a family, that’s clear. And then each child gets 13m²? That’s even true for the children's rooms in my (actually minimalist) 100m² house... Especially since between the lines it sounds like you want to watch the price. Of course, it’s absolutely up to you to inhabit that house size even as two, I just find the term minimalist not appropriate. I have different associations with that...

Yes, OK, I agree with you. Minimalist is not the right term. Let’s call it reduced compared to the original idea. We currently live as two on 120m² and that without kids. Of course, I would like to save a few bucks and reduce the area, but I hardly see any willingness to compromise anymore or sometimes the fear to regret later not having built the 5-10m² bigger after all.

I can't come to terms with this earthmoving. However, if you don't pay the normal price, it can be done.

Different staircase, different room layout, especially on the upper floor, there's still potential.