You definitely need a window to qualify as a bedroom. It has to meet certain requirements that basically boil down to "could a 10-year-old escape a fire through

You definitely need a window to qualify as a bedroom. It has to meet certain requirements that basically boil down to "could a 10-year-old escape a fire through this window?" Although "not falling to death after climbing out" isn't a requirement. I believe technically a bedroom in the US is also supposed to have a built-in closet of some sort and a door that closes the space off. Lack of either of these often means a room is marketed as an office.