T.S.
As a mom of a three year old that has 'space issues' I have dealt with this issue. For months I beat my head against the wall. On day while online talking to other mom's I learned that I was not the only one. I got some really great ideas most kids refusing to sleep in a bed need or want the restriction of a crib. If you are dead set against setting the crib back up try a bedrail (if know someone handy make one that) or get your son a body pillow that you put next to him. Even though he could still roll off the bed the pillow creates a soft yet safe boundry for the child. The rail worked for us we made one that contained him in was only like 8 inches high and left an opening at the foot of his bed for easy and safe exiting from bed.