Having trouble finding insurance on detached unit

[Amit Patel]

Hello, 

I am closing on my first property soon! It's a SFH 3/1 with a detached mother in-law suite 1/1. The units are currently rented separately and with a rent increase on the back unit, it is a great deal. However one hiccup my insurance broker dropped on me is that he cannot find any insurance company to insure the detached unit as technically is an "other unit" like a shed or garage. So the most I can get is like 10% of the coverage for the front unit.

I feel that this set up is an extremely common and I am surprised insures won't fully cover the detached unit. 

How big a deal is this? Should I get another brokers opinion? Thanks!