You can report the illegal conversion or alteration of a building. Illegal conversion or alteration means using or modifying a building without approval from the NYC Department of Buildings.
This can include illegally renting permanent housing to guests who stay less than 30 days.
An SRO unit is one or two rooms and either lacks a complete kitchen and/or bathroom or shares them with other units. SRO units are also called rooming houses or boarding houses. They are often furnished and rent is usually paid weekly or monthly.