Would this be considered house hacking?

[Brian Falcon]

My son just went off to college and we are considering looking into a duplex to use as an investment property.  Would it be considered a house hack if our son lived there (not us)?  Or does it have to be a primary residence for the loan holder (us)?  And if the latter, is there a way to get his name on the loan application as co-owner?  TIA!