This question has perplexed many for years and always gets a mix of answers. And depending on who you ask you will get resounding answers that they are sure are correct (agents, inspectors, appraisers, lawyers, friend of a friend a friend who knows the mayor, etc, etc). First, local building codes may have their own requirements that are more stringent so that's where you need to go, and that's who you should verify with first. Take five minutes to call the local building dept. and you should get a quick answer.
I can tell you what HUD defines as a bedroom for appraisal purposes, coming directly from the National Association of Realtors and part of the CMA class offered by NJAR (New Jersey Association of Realtors) and when doing a comp analysis, as this:
- 90 square ft minimum
- Window for emergency exit (local codes dictate size, ie: 5.7 sq ft clear opening)
- Natural light and ventilation (ie:window)
- Hallway access (direct or tandem such as a railroad style unit)
- Closet NOT required
- Heat source NOT required (I asked twice, I was shocked!)
Screenshot below from NJAR:
My last thought - what would the average person expect in a bedroom for a comfortable living arrangement? I would want more than the"legal" definition thats for sure! Like heat and some form of storage. It's surprising how many homes or apartment listings call a room a bedroom that the average person would not be comfortable with, but can fall under the legal requirements.