Floor plan - plot for a single-family house, slight slope approx. 175m²

Here is a suggestion with an entrance without stairs.

Here this could fit well: CONCEPT-M 152 Musterhaus Pfullingen

in house width 942 / gable width 880. The OP would need to give a clear statement about which width to search the catalog for.

Bien-Zenker now has a website (presumably a landing page) only for hillside chickens. I would definitely inquire there.

Thanks for the PM with the source. Unfortunately, there is no specific house to be seen there, nor any correspondingly purposeful filtering of the entire catalog. I see zero hillside and especially explicitly split-level expertise there. A lot of hollow blah just above fortune cookie saying level, not even remotely naming horse and rider. That you can terrace four basements under an apparently bungalow on the mountain side says nothing about specific hillside houses, for which one will probably have to switch to the custom design route :-(