Would you consider this a room?

[Eric Long]

I am looking at a duplex (top and bottom unit) and the top unit was listed as a 3 bedroom, 1 bath. However, one of the rooms, while big enough and contains a closet, looks like it used to be a former mud room of sorts? There are stairs going up to the second floor on the outside and the door into the top unit goes into this room (the main entrance is through the staircase inside so these stairs are never used). Further, it doesn't have direct heat but, instead, uses a space heater. This is located in Indiana and I talked to the realtor about it's status. He said it is technically a bedroom but I have a hard time being able to honestly say that it is a room.

I've been comping treating it as a room, but I'm wondering if I should be comping 2/1 instead of 3/1 homes. 

Have any of you had to deal with a similar experience? How should I proceed with this situation? 

Thank you!