Over my time in Budapest I have rented three apartments, one in Jugendstil and two in slightly earlier historic/eclectic style. What I cannot get over is how bad the soundproofing is, even in stolid 1900 houses?? I know Hungarians like to listen to the television LOUD, but I can even follow whole conversations through the wall...
Maybe I am just continuously unlucky, but if anyone knows of houses without this problem where there are flats to rent, I would be happy to know! Personally, I find flats which look out onto roads are better, because the traffic noise drowns out any sounds coming through your walls from the neighbours!