Our ds slept in the family bed (mostly) until he was 5 1/2, then he shared a room with his sister for awhile. That wasn't working so well once he started kindergarten (being on different schedules) and he was to the point where he kind of wanted some space for his "stuff". So, he was about 5 3/4 when we moved him into the basement. I wish wish wish we had another room upstairs! Both dh and I still don't like him in the basement. But, he has an egress window in his room that he knows how to use, we have smoke detectors and we use a baby monitor in his room. He sleeps well all night and he is fine in the basement, not scared, etc...I do think he would prefer to be upstairs, but he's also not upset about being down. Our house is pretty small (so its not big of a journey to come up).<br><br>
Personally, I would not have been able to do it any sooner. I'd also be a bit worried about a tired kid falling down the stairs. Good luck with your decision, it's a tough one! Trust those instincts!