Hi Mike- There are also minimum room dimension/ square-footage requirements to be considered a bedroom- per Mass Code. Might be 7x8 feet- not including the closet space. Not 100% sure.
Similar to what the person below mentioned- you should find out about what the septic system / design is to backtrack to what is a legal bedroom in the house.
If the septic was approved and built as a 3 bedroom and that's on record, it doesn't matter if this room is perfect, it cannot be used a bedroom without septic alterations/ enlargements. So it would not officially be a bedroom.
If I can help in any way further, please let me know. Thanks,
Ken L.

Mike,


door+window+closet = bedroom

Mike, I believe the requirement is "confined" space with a closet.

Dick

Hi Mike,

The room needs to have a closet to be considered a true bedroom. Living in Bridgewater myself, one bigger concern is to find out the size of the septic system to determine the amount of bedrooms actually existing in the house.

In the state of MA there needs to be a closet to be considered a legal bedroom.