My understanding is that if it's a local "Durham" historical district then it's a big pain with most exterior changes needing approval. 

Last week was tough because I bought the property under the numbers and assumptions the prior contractor had quoted me and were approved by my lender.

As others have said, there are cheaper, code-approved ways to accomplish your goal via GFCIs or single point bonding. 

Your broker may have forgotten, but when the appraiser reports back to the lender that it is a rooming house, the lender will walk away or only underwrite an LTV of 50-65%.Your best bet is either a private lender or finding a conventional lender which uses auto-approval software (TD is an example) and mortgage agent/broker who can steer you towards an application that qualifies for auto-approval (if at all possible).When we were first in the same situation, we approached a family member with a proposal to have their name on title and live in the house (rent and utilities free) in exchange for their serving as the Den Mother to keep the house in order.  

I've been pre-approved for a 2 family in Queens , Ny for 750k , I'm looking to house hack .

We have the next deal lined up, and we are approved, just need to let the bank know what we need.

I've been DU approved for refinancing.

I put one on instant book and one I had to approve within 24 hours or decline. 

Reason for being listed as a SFH is because permits have not been submitted for approval.

They most likely won't give you a "pre-approval" until you take the course.Good Luck!