Land planning on a gentle slope

Hello dear forum community,

I have been reading along and browsing the forum for quite some time now. For our planned construction project, I ask for your assessment and your advice. It concerns a plot of land on a slight slope and the planning of the building on it. To better illustrate, I am attaching a sketch plan with the measured elevation points as well as the maximum building footprint. We are currently in the floor plan planning stage; the footprint might end up somewhat smaller as a result. The height difference within the max. building area is about 1 m depending on the arrangement, possibly slightly more diagonally. If the building footprint ends up a bit smaller, the max. height difference would also be reduced.

We have already commissioned a soil survey in advance, which recommends either a load-bearing slab with frost skirts or a strip foundation (we had already indicated beforehand that a basement is not necessarily desired). The transition to solid rock occurs at about 2.80 m.

Our plans, based on the soil survey, foresee a building without a basement. The plan is to place the building as lightly as possible into the slope to reduce the height difference somewhat. Now I have read a bit here on the forum and am no longer sure whether this is sensible and works as planned. How do you assess the situation? Is a slab foundation sensible and structurally possible? Are (southeast-side) L-elements necessary, or can the slope possibly be cut back due to the size of the plot? How high do you estimate the overall costs for the earthworks?

Note: The terrace is expected to run around the southeast corner of the building.

Thanks in advance for your advice!

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Is a slab foundation sensible and structurally possible?

Yes, why not?

For our planned construction project

What do you want to build?

We are currently in the floor plan design phase

Then just show it.

From about 2.80 m the transition to bedrock takes place.
Our planning, based on the soil report, foresees a building without a basement. The plan is to set the building as lightly as possible into the slope to somewhat reduce the height difference. Now I have read a bit here in the forum and am no longer sure whether this makes sense and works as planned.

Two point eighty from where? – I don’t see any borehole points marked, and to which one(s) would that apply?
Slope in the terrain also means slope for surface water, which limits the options for omission. If you have not only read but also understood the 11-ant basement rule, then you know: it’s not only the basement that costs, but also the terrain modelings not used for a basement.
How one can approach a floor plan without having processed the deductions from the topographical findings is beyond me. You can almost plan the same cloud-cuckoo lands as if you didn’t know the property yet.
There are several people here who understand soil reports and can work with them. You should show that, more urgently than your own floor plan etudes.

Yes, why not?
What do you want to build?
Then just show it.

I have become uncertain about the construction with a slab foundation due to the above-mentioned height difference caused by the slight slope. We are still at the beginning of the floor plan design. It will take a while before I can show something. First, we must clearly determine whether a basement is necessary or sensible.

Two point eighty from where? - I don't see any borehole points marked, and to which one(s) would that apply?
Slope in the terrain also means slope for surface water, which limits the possibilities of omission. If you have not only read but also understood the 11ant basement rule, then you know: not only the basement costs, but also the terrain modifications not used for a basement.

Two boreholes were made for the soil investigation - one each in the SW corner and in the NE corner of the marked building footprint. 2.80 m from the ground surface. More details enclosed in the key statements of the geotechnical report. It is clear that additional costs arise from the excavation work and terrain modifications.

How one can start a floor plan design without having processed the conclusions from the topographical findings is beyond me. One might as well design the same castles in the air as if one did not yet know the property.
There are several people here who understand soil reports and can work with them. You should show that, more urgently than your own floor plan drafts.

The starting point here was the geotechnical report, which, as described, recommends either a load-bearing slab foundation with frost skirts or a strip foundation. We are still relatively early in the floor plan design, and while researching here in the forum, I came across the topic of basement / slab foundation / earthworks again. It is completely clear to me that a basement naturally has an impact on the floor plan.

For further assessment, enclosed are the key statements of the geotechnical report with the request for your evaluation.

It will take a while before I can show something. First, we still need to clearly determine whether a basement is necessary or sensible.

That's how it is, and therefore I also have no idea where ...

Two borings were carried out for the soil survey - one each in the SW corner and in the NE corner of the marked building footprint.

... this assumed specific footprint along with its location comes from, for which, by the way, two boring points are very sparse.

2.80 m below ground surface.

Two point eighty below 452.56 would be 449.76, that would be only 1.09 m below 450.85. Apples and oranges.

Here so that can better imagine it. In the house, 1.5 m difference. Of course with a basement or better a lower ground floor if the budget does not allow it.

Is there no development plan?