NYC: Adding 2 addl floors to 2 floor MFH

[Ben Cohen]

Hi everyone,

I'm in the process of finding a house hack in NYC and just saw a 4 unit MFH home (2 floors, 2 units/floor) that has the FAR to add up to 2 additional floors, for 8 total units. I'm thinking of using a HELOC on another home to fund such a project, which would be overseen by my father who is a contractor. Then refinance and buy more properties. So sort of a BRRRR where the "rehab" is adding more units.

Has anyone in the NYC area (or frankly anywhere) had experience adding multiple floors to an existing MFH building? Would love to know about:

- Cost

- Are permits required? What’s the timeline like? Is there a lot of bureaucracy?

- Can the tenants on the second floor (the current highest floor) stay there during construction?

- Any recommendations for good architects?

- How long should this take?

- The building is semi attached, and the other building is the same height. The rubber roof is divided by a mini wall. Does this pose any problems?

Thank you in advance!