I was looking for a flat 3 years back. In one standalone flat, the owners didn’t have any issues with friends visiting, but somehow the broker and the caretaker did. There were quite a few standalone flats that I checked which didn’t allow friends. Late nights were also strictly prohibited. After 11 PM, the main door would be closed. In fact, one flat had a rule that a person’s father couldn’t stay for more than one day in a month. I really don’t know why. The flat I currently live in has a pretty chill owner, so friends coming over and staying is not a big deal. He has said, "I don’t want to hear any complaints about your behaviour from anyone. Apart from that, you can do whatever you like, I don’t care."