How to correctly analysis the numbers?

[Denise Cazares]

Hey BP members. I am a new investor in the Chicago market. My question is about how to do a correct property analysis. I see properties on the mls that are listed as 2 flats. Everyone in Chicago knows that most two flats may also have a basement or an attic or both. Sometimes one if not both maybe rented out. Do you put that rent into the analysis, knowing that these units may not be legal?