Bedroom Addition in Boston

[Adam Eckerman]

I'm looking to add a couple walls to add a bedroom in my condo. I also have a small room with a closet that I'm also considering making a bedroom; however, I'm having trouble finding the codes that regulate what makes a bedroom legal in the city of Boston. 

My main question is about the smaller room and legal means of egress. It does NOT have any access to public exterior (yard or alley), and it is in the garden level. The room is 156 sqft and has a closet. It also has heating and AC as well as smoke detector. Does it need a second means of egress (window) to be a legal bedroom? Any input is appreciated. 

Also I'm looking for a contractor for some work in my condo, any contacts would also be appreciated! 

-Adam