FHA Co-signer with similar credit and DTI?

[Andrew Sprague]

I'm thinking of having a roommate co-sign on a 3-unit through the FHA program. My roommate has essentially the same credit, DTI, income, and age as myself so there should be no issues qualifying for the loan on the house. Is there anything that I'm overlooking, would both of us have to live in the house or just one? Any advice or feedback on co-signing an FHA loan would be helpful.