It had been agreed before I booked this room that we can check out at 12:00 noon. That was the main reason I chose it.
I had only 3 hours of sleep in London and saw as very very unpleasant that 1 hour before my check out (at 11:00) another guests opened the door of my room and I had to solve that. It is unacceptable that anybody else can enter the room during my stay.