'All bills included' accommodation is quite popular in the UK (known as HMO's), and very often people try to get away with running ASIC miners, however they are typically caught and stopped very quickly.
What you're basically planning to do is exploit your landlord, and it's not cool.
I think qm stands for "quadratmeter" aka square meter, which IIRC is a German thing, so I guess he is somewhere in Germany unless he meant to type sqm. Obviously, your logic still applies regardless. Anything beyond a tiny USB miner is going to be spotted by the landlord and what happens next is up to the laws of where he lives. Most importantly, a 50m2 apartment is terribly small -- no mod of any kind is going to let you sleep with an S19 in the same place.