Soundproofing / Thin walls in prefabricated house, solution by Okal company

Hello,

we are currently interested in purchasing a prefabricated house from the company Okal Haus.
This is being built as a "house in house" solution, which means that a wide single-family house is essentially built and then split in half with a double "outer" wall including an air cushion between the walls.

Does anyone have experience regarding the soundproofing, on the one hand towards the neighboring house and on the other hand how thin-walled the house is inside? (If a child takes a step in one corner of the house, can you immediately hear it in the other corner)

Thank you very much in advance for the answers!

Good evening,

just for better understanding:

This is being built as a "house within a house" solution, which means that basically a wide single-family house is built and then divided in half with a double "outer" wall including an air cushion between the walls.

You don’t mean the classic semi-detached house, but a house with one entrance, behind which two apartments open up? So divided according to WEG?

Rhenish greetings