Insulate floor slab - ceiling height is not sufficient

Hello everyone,

we want to buy the timber-framed house of my mother-in-law, as it is now vacant. Technically, the house is in the condition of 1944, so more or less everything needs to be redone.

Here is the problem or question: on the ground floor there are several rooms with concrete ceilings above a basement. On top of that lie beams sometimes insulated with glass or stone wool, and on top of that chipboard and PVC. Total height maybe 15 cm. Then there is another room below. Concrete floor, not basemented. PVC floor on top.

Since the ceiling height is not sufficient (door passage height 1.99 m, ceiling height maybe 2.2 m) insulation will be difficult.

Therefore the question: how serious is it if a single room in the house is not insulated downward? Attached is the floor plan of the ground floor (it concerns the room outlined in red) and a photo of the room.

Maybe someone has an idea without the need to replace the floor slab?

I would check whether it is actually a slab or just a screed on earth. In the case of timber-framed houses, usually no slab was poured. If it is only a poured floor surface, get rid of it. Depending on how the foundations are laid, the new floor can also be placed deeper to gain ceiling height.

Thank you! I am also considering whether it would make sense to tear out the trash. No idea if the house will then collapse.

My father-in-law just called again, he had forgotten the following:
It could be that there is a filled-in cellar under the room. But no one knows for sure. In any case, it is "Stampfbeton" as the floor, he says.

Take a look at dry systems for underfloor heating with insulation.

For example, Cosmo Top 15, where you get "a bit" of insulation and additionally a warm floor with minimal installation height.

Pumped concrete for a floor??? I think he simply means an unreinforced floor. If it is a real half-timbered house, then the floor slab has no structural function.

There are vacuum insulation panels from 10 mm thickness, which already correspond to 50 mm of conventional insulation. However, they must be precisely fitted as they cannot be cut.

So remove the old covering, check if you can go deeper (in the screed), if necessary use leveling compound for smoothing, vacuum insulation panels, and then a thin covering (about linoleum) on top.