Styrofoam granulate at different raw building floor heights

Thank you all for the answers! :)

You probably mean perlite? That’s what I would have thought of rather than polystyrene granulate. A carpenter once told me that to compensate for small unevennesses, he first lays down 2-4cm styrofoam boards on the floor, which absorb small bumps etc. On top of that, he then places, for example, his beam construction or other floor build-up. A loose fill and then the boards sounds like a sensible measure to me. Maybe you have some pictures so it’s easier to imagine. I read about 28cm height, so there is room for quite a bit of insulation. o_Oo_O

Here is a picture where you can clearly see the transition from a basement (high floor) to no basement. We can still chisel away the smaller unevenness. The screed company always talks about styrofoam granulate, thermal conductivity 0.043 W/mK.

Different settlements are to be expected. In the area of the [Uebergaenge], be sure to lay a mat in the screed, otherwise cracks will appear eventually.

Alternatively, provide a joint in the area of the [Uebergaenge].

Not only the insulation is important. For example, I would recommend anhydrite screed, which has high bending and tensile strength. Furthermore, it requires a shorter drying time.

What kind of mat would that be? Would it then lie, for example, at 7cm screed thickness, so to speak halfway up in the screed? Good point about the anhydrite, thanks.

Just a really stupid question. I can't see exactly from the pictures how it continues next door each time. Couldn't you just remove this raised area completely so that you have both on the lower level. It looks like there are perforated bricks or something similar on the floor in the picture....