The foundation on the gentle slope

Hello

The building plot for our single-family house (living area 120 m2) is smaller (400 m2) and there is a height difference of 1 m over 15 m (6.6%). We are not planning a basement and the question arises which type of foundation we should use. Of course, the structural engineer must calculate everything in the end, but I would like to hear about your experiences with sloping sites and get a feeling for whether we will need to invest a lot more because of the slope.

If a retaining wall has to be built, is a slab foundation necessary or is a strip foundation sufficient? Could the strip foundation take over the function of the retaining wall?

Thank you very much.

1m height difference doesn't sound like much. How much height difference is there then in the area where the house is located? Of course, it also depends on the height at which the house is supposed to stand. Maybe you can provide more information on that.

And then it probably also depends on how load-bearing the soil is, etc. Is there already a soil report?

Hello

The difference is linear and is about 0.9m in the area where the house stands (14m length). We do not want to "bury" the house, but the house should be built at the highest point.
Topsoil:
Silt, slightly fine sandy
slightly humic, root-penetrated
Homogeneous zone E1
Class 1
very frost-sensitive
Loess:
Silt, slightly fine sandy;
Silt, slightly clayey to clayey, partly slightly fine sandy
Homogeneous zone E2
Class 4, locally Class 2
very frost-sensitive

Well-founded answers will certainly depend on the location & orientation of the house as well as the planned outdoor facilities. Just post some more info ...

What I learned during our construction phase is that the "Sommerfrost" has much worse consequences than just having to build frost-free. Sommerfrost refers to the drying out of the deeper soil layers with the associated (stand) strength loss. That's why almost every builder will have to deal with more excavation anyway, with or without a basement :rolleyes:

Here is a small sketch of the orientation and inclination.

Can you make the house more elongated and rotate it clockwise? So build it parallel to the contour lines. That would, in my opinion, fit better and you would have a larger area to the southwest. Besides, on a south-facing slope, it makes more sense anyway to orient as many rooms as possible to the south (possibly with a valley view).