to open a hostel in New York City

I would appreciate some direction, I want to convert a commercial building into a hostel in New York City,the architects and the expediters I'm approaching have no knowledge of the requirements,and how to set it up with the building department, if somebody could direct me to a good architect or expediter that has done this before I would appreciate that, and I would also like to know if there is a law in New York City that you can't have more than three people that don't know each other in the same room in a hostel, thank you. Joel