Too many assumptions. 

We ran the numbers assuming the current sub-market vacancies but there is a flaw in this assumption because there has been a lot of large new construction 100+ units buildings that are now on the rental online and on the market.

It more of a capital and lease-up assumption.

@Evangelos Mavros I'm going to make an assumption (correct me if I'm wrong) that you are looking for an investment property to use as STR/vacation rental.

Again, others might feel differently here.3) property level due diligence: (takes seconds to weeks per deal): here is where I drill in with the low-level details.a) pro forma popping: I examine all the assumptions, and see if they are overoptimistic or not.

This is my assumption. 

(I'm making an assumption here about your finances, if I'm incorrect then my apologies.)   

It is mostly about the borrower, the property and the business assumptions when funding a project.John Corey

My assumption is risk could go up for a bank so they may ding you with a higher interest rate for 'hospitality' or 'STR use" than  a mere multifamily use??

Bring in the assumption!