The way it was in our (my husband's and mine.... kids are like guests.....) house and teens don't need the level of privacy that adults do. The right to it has to be earned.
In our house it was an open door policy and unless you were undressing or changing your clothes your bedroom door was open, all times.
No TV or friends in the bedroom. We made our basement into a room for our kids and friends to watch the big TV, a table for board games, a little fridge for fruits, sodas, water and juices. Stipulated that we adults and the others kids parents could come down anytime. It was a "Teen Center" with serious chaperones. Backyard grilling and basketball playing. Water fights, Pizza parties. Comfortable deck for a conversation. Intense parental involvement.
In conversation we were open about all subjects (although my husband cringed at that). I had a lot of self control because an older friend had given me a great advice that it was not to react when a teenager says they are going to do something. 95% of times they forget about it while we stress over it.
That changed when they went to college, learned how to live in one single room. They came home and their bedroom doors closed but they had earned the right to do it because the way they performed when not under my wings. I trusted them.
Now my daughter is a counselor and 29 years old. She said she will do the same as we did with her kids.....that very "Gentle Dictatorship" as she calls it, I carried on. Strict but very fair.
I considered it a compliment.