Converting a 3 unit into a 6 unit in Chicago. Costs?

[Mark Goodman]

I am looking at a very old 3 unit building in Chicago. It's zoned as a 6 unit and sits on two Chicago lots. I am expecting a full gut rehab here. I think the structure is sound, roof sound, windows okay and brickwork in good shape. Any idea's how to do a rough calculation on rehab expenses? Anyone want to come out and look at it and give me a ballpark figure? Any recommendations for contractor or architect? Any information greatly appreciated. Thanks!