@Gordon0
For entire apartment listings in NYC one and two families are the only ones that do not violate the multidwelling law. There is also the C of O, there was a case in Brooklyn where a one family thought it would be good idea to convert their carriage house for transient rental unfortunately the C of O was updated to a two family and now was in violation. WNYC wrote an article titled
“Think Private Homes Are Safe to List on Airbnb? Think Again”.
There is also the flip side building inspectors have stated incorrectly that some two families are illegal for the number of guests listed because they incorrectly calculated the useable square footage of the apartment.
The most recent proposal is to require registration for transient rental in NYC requiring the registration number to be in any advertisement. I am not sure how
much traction that has gotten though.