There are a total of three "pillars" in this area.
[*] Pillar 1 is the chimney of the central heating + unused chimney, so a double chimney. It is located near the planned bathroom or the kitchen.
[*] Pillar 2 is the chimney directly at the apartment entrance. This is intended for a wood-fired stove and is currently used from the ground floor.
[*] Pillar 3 is a solid pillar (see last attached picture). This pillar supports a lintel and a wall that has been built up to the roof ridge. The "small" section of the ridge rests on it.
Ok, then I'll skip philosophizing about the grain size of the plaster on the columns. I have revised my floor plan sketch and have now fully included the dimensions of all columns. (see attachment).