Based on the information provided and the fact that the subject property has "single family" status there is every indication that you would encounter difficulty. There would likely be considerable code adjustments and zoning issues with which to deal with.
The best source for accurate information will be via the Hillsborough municipal services.
Single Family Home usually means just that (ONE FAMILY)
Some cities have laws that prohibit "CROWDING" a term used to describe multiple families living in a SF home.
Best of luck to you,
Kawain Payne, Realtor