FHA Duplex w/ Cosigner

[Thomas Alexander]

I am finding a lot of conflicting information online and was hoping for some advice. I am looking at a duplex that I want to purchase using a FHA loan and my mother as a cosigner. I was told that since it is a multifamily with a non-occupying co-signer (although I will be living in one of the units), then the loan becomes a 20% down payment versus the standard 3% down FHA loan. Is this true and can anyone confirm this?