What constitutes a legal bedroom in MA?

A room that can only be accessed by walking through another bedroom is problematic. Building codes require bedrooms to have two means of egress, typically a door to a common area and a window that meets escape requirements. If the only way to exit bedroom A is through bedroom B, bedroom A likely doesn't meet egress requirements because its escape route depends on another private room, not a common hallway or living space. Check with your local building department in Massachusetts for the specific code requirements in your municipality. Some areas may have different interpretations, but generally a bedroom that requires passing through another bedroom to reach a hallway or exit is not considered a legal bedroom for safety and code purposes. This matters for listing purposes, insurance, and appraisals. If the property is listed with more bedrooms than it legally has, that affects value and buyer expectations.

It sure can! You see this a lot in urban areas. While not ideal, it can maximize the bedrooms available, normally in rental units.

Possibly not, if I understand your situation correctly. In Florida, they following is needed to be able to consider a room a bedroom: Key Florida Bedroom Requirements: - Size: Minimum 70 sq ft floor area. If the room is for more than one person, the required space increases. Dimensions: At least 7 feet in any horizontal dimension. - Emergency Egress (Crucial): Must have an operable emergency escape/rescue opening to the outside. This window must have a net clear opening of at least 5.7 sq ft (5 sq ft if at ground level), be at least 24" tall and 20" wide, and cannot be higher than 44" from the floor. - Ceiling Height: A minimum of 7 feet in at least 50% of the room. - Access: Must have a door leading to a hallway or common area, not exclusively through another bedroom or bathroom. - Heating: Must have a permanent, safe heat source, not a portable unit. - Closet Requirement: Interestingly, while many local Florida municipalities and real estate agents expect a closet, the Florida Building Code does not strictly mandate a built-in closet to define a bedroom. However, for appraisal purposes, a closet is usually expected. - Conditioned Space: The room must be heated (and usually, in Florida, cooled) to be considered living space. The "access" piece may be the item in question; AND if this room is considered a bedroom, it may make the other bedroom ineligible, if that room's only access is through the room in question.