How high does the house rise - how high to pile up earth (cellar depth low)?

The terrain elevation is shown on the plans (see earlier). That it is impossible to create would first have to be proven by me and probably is not the case. And that exterior facilities are not included is stated in the contract....

I never said it would be easy, and everyone here has already pointed out that you approved the matter and now have the hot potato. The question is whether a terrain elevation is actually possible without further ado. Here, the neighborhood law (keyword shading, nuisance) could be brought in and also check whether there are restrictions regarding terrain elevation from the development plan. So far, we have only seen your own scribbles in the views, right? The question there is whether it is clearly apparent to a layperson what costs and disadvantages the matter brings and whether the lack of advice is to blame. I am not a lawyer; the chances of getting anything out of court here are probably slim and only if some regulations were violated or continuing construction as planned is impossible. The more reasons you find why it is a disaster, the more ammunition you have to burn. But I would first complain to the general contractor without a lawyer or make a fuss (depending on what works better). Most likely, in such cases, one agrees on additional services to be provided. These do not hurt the general contractor as much when he is still on site and help you best.

I just enthusiastically read the thread. I would summarize the last 16 pages as follows:

1. Money for the lifting station should be saved
2. General contractor with a cheap offer was sought
3. General contractor proposal with high-rise planning was approved 1:1 by the client = thread creator

==> The result is that the house construction ended up as expensive as with a basement on a normal level with a lifting station - probably even significantly more expensive currently. In addition, you can pee on some neighbors’ heads from your garden. Terrain modeling will likely be a poorly usable disaster (with slope you lose much more expensive land) or an expensive pleasure. Rainwater drainage towards lower neighboring properties is also complex. And the general contractor delivered exactly what was ordered. A cheap house.

My only suggestion: Go to the garden landscaper with the current state (and do not pile up clay, such soil is not suitable for the property - there is a reason why you get it for free). Also, rather triple your T€30 budget.

The question is whether a terrain elevation is actually possible just like that.

BayBO allows 2 meters.

The more reasons you find why it is a disaster,

However, I have the feeling that the original poster does not perceive it as a disaster at all. For me, the focus on terrace filling without any consequences for the neighboring areas (not the neighbors on the street) is too present. One meter I initially see as unproblematic, even without L-bricks, since the surroundings have also been filled. I only see the connection to the different areas as very mixed, especially in the area of the intended terrace, since the neighbor apparently is level there.

Just to clarify: The missing 2 meters result from the 1 meter excavated for the basement construction plus the elevation of the house? So basically you are only building 1 meter higher than usual for the area?

It feels like we would be 1.30 meters higher than usual for the area, i.e. than the neighbor, if we were to pile up the full 2 meters as originally planned and which is continuously advised against here,

1 meter of slope all around is not that serious and can also be made visually appealing. But the substructure of the hill will be expensive, and I would ask the general contractor why a pit wasn’t used instead of excavating 1 meter. On undisturbed soil you would have significantly fewer costs and worries.

About 1 meter was excavated to go about 80 cm into the ground with the "basement." The topsoil that was removed is placed at the back of the property and can be reused. What is meant by the "substructure" of the hill? We know that compacting material must lie under a possible terrace.

It feels like we would be 1.30m higher than usual locally, i.e. than the neighbor, if we were to heap up the full 2 meters as planned and which is continuously advised against here,

Almost 1 meter was excavated to go about 80 cm into the ground with the "basement". The humus that was removed lies at the back of the property and can be reused. What is meant by the "substructure" of the hill? We know that compacting material must lie under a possible terrace.

Normally, you only make a pit for the basement plus movement space. You don’t excavate the entire area down to the basement slab. That’s almost a foolish act. If you heap up two meters of earth, then compared to natural soil you have a loose hill that is not fully load-bearing and can be easily washed away. If you work a meadow with a spade for the first time, you need a lot of strength; when you fill the hole with excavated soil and compact it, it is still much easier to dig in that spot afterwards. You cannot bring so many tons of equipment onto the 2 meters so that it becomes as firm as natural soil.

I also suspect that obtaining the general contractor’s approval isn’t possible without huge fuss involving a lawyer. I think my first step would also be to go to the landscape gardener to get an initial assessment of what’s possible, what you want, and how expensive it will be.

I can hardly imagine a staircase as wide as the double patio doors visually – it would have to connect directly to the patio doors, right?

I was rather thinking of a balcony and then a narrower staircase on one side. I can imagine several variants there. Either a larger balcony and then no regular terrace at all (I would still want a staircase to the garden) or just a smaller one and then a bigger terrace below. Or almost no balcony and mostly stairs. I think the suspicion here is that this might be cheaper and you can use more of the garden than if you forcibly pile everything up to the patio door + terrace and then have to cut steep slopes and secure them strongly.

But again, a note here, we are laymen and this is the impression from a few photos and drawings :) The landscape gardener can possibly provide more ideas and also an estimate of which options should be pursued further and which shouldn’t.