If you're refinancing a mixed-use property, then the results of the mixed-use test are what tell you whether you have a HMDA reportable refinance. If you're refinancing a loan secured by multiple properties even one of which is a dwelling, it's a reportable refinance. Your scenario sounds like a mixed-use property where the business purpose part (1 bedroom being lived in by the borrower versus 3 being used for transitory dwellings??) would outweigh the consumer part. Just my interpretation.
I'm fixin' to fix that.