Fannie Mae is confused about their own rule and I haven't been able to find any guidance on this at all, outside of what the escrow officer wants to get the loan to close.
Supposedly its to help offset coverage for 'walls-in', meaning it should be building coverage. Problem is, some HOA policies are actually walls-in already, so it becomes somewhat duplicate coverage.
I just tell my insureds to add it on, get the loan closed and then if they don't want the coverage we can discuss taking it back off. Just get the loan closed FIRST. Don't stop the process.
Of course, I do recommend they keep the coverage and explain that it is a valuable thing to have if something should happen to the unit, especially if they have done any work on the place at all.
The thing is, they don't know. They just know 20%. I explain to the insured that my goal is to not be the obstacle to them getting a loan. Make it happen first, straighten it out later.