1 - 4 units are residential lending
5 + units are commercial lending
Commercial loans are generally at a greater cost and interest rate.
Residential loans are less expensive.
The income of the property can be used in a residential loan.
The income of the property is usually the only thing used in a commercial lending.
If your husband co-signs that means he is on the loan and on title. Basically he is a co-borrower or a joint borrower.