Opening a Hostel / Noclegi / Apartaments in a normal Flat - What permissions do I need in Poland?

Everywhere all over Poland I see hostels, apartaments and noclegi for rent in normal flats, with owners living right beside it.

Whose permission do I need to open one - the City AND / OR the fellow flat-owners in the building?

If the other people in the apartment block don't want this type of business can they block me?

I think both.

Initially I thought you don't have to have any permission to privately rent a room or house to tourists in Poland. At least that's how it worked before Poland entered the EU.

Today.. it's a little grey area. If a home owner rents a room or house sporadically, I guess there's no need to worry about and just do it. But if they have a dedicated housing and host tourists more than a few months a year, they must have some formal license to do business. That means they have to pay 8% VAT (or more), but it's probably voided if the housing is managed as an "agro-business." Some more details:

- Rooms must be heated (from Oct to Apr at least),
- Tourists must have access to hot and warm water,
- Tourists must have access to a toilet/bathroom,
- At least 6 sq/meter per 1-2 persons in a room.

I don't think other people can prevent a home owner or apartment owner from renting it to other people (but then if they are hostile towards you, you need to make sure you have the legal permit I guess).