Homeowners Insurance for Duplex???

[George Williams]

I am purchasing a duplex (FHA), I must obtain homeowners insurance prior to closing. I have two carriers quotes: 1) one policy for the whole house; 2) two policies, one is personal and one is a rental. (Cost is almost double) The duplex is one house converted to a upstairs unit and a downstairs unit.

My question is do I need two separate insurance policies or just one? (The second carrier is stating I "need" two policies. 

[The property is in Delaware]