I did it with redstone.
If I was better at room designing and decorating, and I had seen a better spot to make it, it would have been a lot better.
I am going to leave like this; if you like it, ask for it and I'll put a download link here.
By the way, you can copy my door design and do better vault, or do you own one if you want, I would love to see that.
If you want to know, I tried to do something like the vault in Fallout 4, (the one were you start the game).
With rooms and medical bay and armory, storage room, and stuff.
Guess I at least tried.