Permits and such...

Hello, can anyone pls help me with how to rent a place for the purposes of a hostel in Budapest, in terms of what license or permits I would need for the hostel. Its a bit complicated situation to understand because it seems the hostel license there is somewhat anachronistic and incompatible with modern hostel needs, so hostels use some alternate agreement/arrangement. Does this mean that the building committee's official approval is also not required? Would appreciate if some hostellier in Budapest can advise me on this. Thanks/