When did baby start sleeping in their own room?

We tried the bassinet in our room for a couple weeks but our room wasn't the most comfortable place for him. His room is much cozier and has all the things he needs. Luckily, we have a daybed / pullout trundle in the nursery so I've been sleeping in there every night and my husband joins us when he doesn't work. But I'd really like to start sleeping in my own bed and room with my husband soon. We have a monitor, we live in a 2 bedroom apartment so we're close but not enough to hear everything especially over his sound machine. When did you feel comfortable having your baby sleep alone?

FYI I did a little looking into the 6 month to a year recommendation and those studies were done in the 90s in Europe so it's hard to generalize them, the found a relationship with sids but not causation, and were done before everyone knew to lay infants on their back. Some new studies have shown that room sharing parents and babies on average slept less, and were more likely to practice other unsafe practices like bringing baby into your bed. They also found room sharing babies were 4 times more likely to have an unapproved soft object in its crib. Also sleep deprived mothers are more likely to get in a car accident. And just another finding was that parents were lacking closeness with each other. Thoughts?