what does rooms actually mean Living room+bedroom(s).
If it is in the Polish language, rooms means bedrooms plus living room.
So if it is a three roomed apartment, it should have two bedrooms.
Also, I am trying to get my head around Sq mtrs,
There are lots of free conversion programs on the net, like this one
In the UK we go by individual room measurements, with normally a plan.
It is common practice here to get a plan before you even see the apartment.
This will have the room sizes on it.
So what is shoebox size
Here is a very rough calculation.
15-25 shoebox size. (studio).
40-50 m2 1 bed.
50-60 m2 2 bed.
70-90 m2 3 bed.
130 + penthouse.