Just because the majority of square feet is dwelling, doesn't mean the properties primary use is dwelling. That is one factor. If I buy a building that has non-residential space on the first floor and apartments on the 2nd and 3rd floor, the majority of space is dwelling. However, that doesn't make it a "Dwelling" for HMDA.
It could be the non-residential space provides 3/4th of the income. Ask the borrower why they bought the building and most will tell you they wanted the main street store frontage. They didn't want to be in the apartment rental business, but they aren't going to let the apartments just sit unoccupied. In this scenario (which is very common), I would never call those buildings "dwellings" for HMDA.