Living in a Flat that is rented as "Not habitable" - what are the legalities in Poland?

What kind of issues can you run into in renting out a flat that for all intensive purposes is a residential flat, but for whatever reason is currently zoned as a "lokal" "biuro" or other type of business use, but not as a residence.

If you have a rental contract signed explicitly stating that it is Business space being rented, and not for living in - is this enough in the eyes of the Polish law to absolve the landlord of any liability?

I'm thinking like worst case scenario you rent a flat and live in it, and it burns down, yet it was technically not allowed to live there in the first place.

Change of use of the property is defined in Article 71 of the Building Law.
You should report to the local government any change in the use of flat if its effect is a change of the safety conditions listed in the Act, namely: fire safety, flood, labor, health, hygiene and sanitation, environmental protection, volume or load of the structure.

So the content of the contract do not change much if above is applicable.

More detailed information you will find here (polish source):
inzynierbudownictwa.pl/biznes,prawo,artykul,zmiana_sposobu_uzytkowania_obiektu_budowlanego_lub_jego_czesci,6499