Multi-unit Rental Income

[Brandon Shealy]

Hi.  My fiancee and I are looking to buy our first property.  We plan on buying a multi-family, living in one unit and renting out the rest.   

We would like to know, if we are buying a one that already has units being rented out, would we be able to count that rent as income when applying for a mortgage?

Also, if the other units are not being rented, but we plan on renting them out, could that be counted?

Thanks!

Brandon