Floor plan options single-family house 130-150 sqm, 1.5 stories, hillside location

I'll put it this way. Your variants had no access to the garden at all. They were also not usable. The variant only uses the existing soil masses for terrain leveling. The CP simultaneously serves as a retaining wall for the neighbor and the leveled area. Yes, the carport roof and the plateau are supposed to be on the same level. Is the CP allowed to be at the boundary and that close to the street? Depending on the budget, you can extend the CP further into the slope (partial basement for HAR, etc.). (in BY it may be up to 9 m at the boundary) Unfortunately, I am not familiar with BW.

may be that the basement rule refers to a comparison between the slab and an uninsulated basement (does it?),

No, the 11ant basement rule compares the costs of a built basement with those of a basement "avoided" at all costs against the "will" of the property and applies, by the way, already to a utility basement (cold basement). Whether the boundary of the thermal envelope is the ground or a cold basement is unlikely to significantly change the calculation – the insulation of both variants is similar.

I'll put it this way. Your variants didn't have any access to the garden.

I think the problem is also the statement or lack of imagination of how to use the terrace. That’s how it was to be read, right? When the weather is good, you basically only stay inside for the necessary time. The terrace becomes the living area for everything. Even the kitchen moves there, meaning the preparation. And when the grill is lit, cooking is done outside too. Many don’t cook inside anymore at all, but grill outside even in winter. From October to Easter, the terrace is used as a big refrigerator. Starting in March, the terrace is used for potting and planting. In summer, the bike is also allowed to spend some time there. There are people who hardly do anything inside anymore because the terrace is the ultimate place to linger at one’s own house. And outside, between Easter and October, you always have some things to do in the garden, for which the terrace is used as a start and finish point. Why sit inside at over 21 degrees? Indoor sofas gather dust until sunset. The trend is already moving towards a third and fourth terrace ;)

Thank you , as someone who currently lives in a rental apartment, it is actually helpful to hear your explanations – much of it is not even on the event horizon yet, and one probably underestimates the new possibilities one will use once they become available.

What is still unclear to me is the following statement:

Your variants had no access to the garden at all. It was also not usable.

What is meant by this, or where is the qualitative difference to your suggestion? A direct door to the back would be great, but luxury if you can go via the terrace (which might then be used for gardening anyway). I was not thinking of a heavily usable garden in the south, but really consistently behind the house (as drawn – possibly even moving the house forward in the building area for an even larger contiguous garden in the north). Ideally without terracing the slope too much, but rather creating different raised-bed-like areas... but that is all still very open. A classic, flat lawn would not be desired now, rather "natural" and productive – I would then rather put a deckchair to relax than in a decorative garden.

Sure, you don’t want to waste the area in the south entirely, but parking spaces, street, and low height made it unappealing to plant the utility garden there..

Is the CP allowed to be at the border and that far to the street?

CP window is fixed on the dashed line in the plan - but maybe it also has to become a garage, because at the beginning of the property (south) due to a deeper road construction, a not insignificant embankment has arisen (2-3m high), which was not present on the terrain lines..

Depending on the budget, you can extend the CP further into the slope (partial basement for HAR etc.). (in BY it may be up to 9 m at the border) Unfortunately, I am not familiar with BW.

I think the bigger problem here would be building a terrace (the grey area on the left) directly at the neighbor’s boundary.. likewise, retaining walls/fences/hedges at the edge are not allowed to be higher than 1.20 m.

I think the problem is also the statement or lack of imagination of how to use the terrace.

YMMD

CP window is fixed on the dashed line in the plan ...

Who determined that? The municipality? Is that really a fixed designated area for the parking spaces? The building envelope for the house also looks extremely limited on your plan. Is that really correct? If so, such information should be included in post #1 of the thread and emphasized separately, since it would be quite special. So far this is just a confusing mess. I am opting out until there is more clarity.