What part of Philly is your duplex in? 

The only way to do it is to do the work with the city to make all four units condos and then sell the off separately.

He could perhaps also buy a duplex and live in one apartment while getting income from the other.

My business partner and I are about to lose out on a rental condo because the President of this company has completely ghosted us and his own employee who we've been working with directly.

Here in Hawaii, condotel (vacation rental condo) financing is different from typical condo financing, so important to work with a local lender.

There are lenders who can do a cash out refinance for the new appraised value after three months so it can be a good choice for an investor who's doing a BRRRR.These loans can work for investment properties that are long term rentals, short term rentals, non warrantable condos and condotels.

No and you need to put this on hold and research the condo nuke that's about to hit Florida in the form of new legislation that no longer allows condo boards to defer necessary repairs. 

My condo is an HOA that is suddenly non-warrantable for conventional financing.

@Elton Tate is this a single unit or duplex?

For a duplex, you'd likely need to double the estimate if the units are identical.