My kids used to sleep on a bunk bed in the same bedroom. I could go into their room unannounced and be in their space.
Recently, we decided to split the bunkbeds and gave them each their own bedroom.
I now have to knock on a closed bedroom door, for either of them to peer around it and decide if I can come in. Within 24 hours the game changed and with it the rules.
How changing an environment can change how people behave, right there.