if you're looking for a "legal" bedroom - that is legally listed as such for marketing purposes and safety it needs a closet as well as an egress window.
for safety it needs the egress window/door directly to the outside or the aforementioned wet fire suppression.
speaking of fire suppression systems. I was appraising a 12,000 sq ft very custom house with a 17 car basement level garage. they had a giant picture window at the basement level 'lobby' looking out into the garage. it was far cheaper for them to put in a commercial grade wet suppression system in the garage than it would have been to try to get that giant window fire rated.