Can my multi-unit property be eligible for Safe Harbor deduction if I live in one of the units?

The requirement "the property was not used as a residence for an part of the year" is a little ambiguous. The rental units were not used as a residence, and I allocate only the expenses from those units and allocate per square footage for any building expenses (like roof patching.)  Why would this be any different than someone owning a couple condos (which would clearly not have been used as a residence.)

Thank you in advance.