Investment duplexes underwritten as 2 homes?

[Heidi Schmid]

I have 3 properties in California.  Each one is a duplex or triplex and because the buildings aren't attached my insurance carriers having started writing them as separate properties so I feel like I've been paying double the insurance premiums of what I should.  If there is a garage, that isn't written separately, but the living buildings are.  Is this normal?  My places are small and older and it seems like I'm really over-paying.