Uniform Fire Prevention and Building Code:
CO detection is required for one-and two-family dwellings and multiple single-family dwellings (townhouses), as well as dwelling units in buildings of Group R-2 occupancy and classification owned as condominiums or cooperatives. At least one CO alarm shall be provided in each dwelling unit, installed in the immediate vicinity of the bedroom(s) on the lowest floor level of the dwelling unit containing bedroom(s). (Effective date: March 6, 2003)

Residential Code New York State §R313:
CO alarms must be installed in detached one- and two-family dwellings and townhouses of not more than three stories. This requirement applies to structures that contain a CO source including, but not limited to, fuel-fired furnaces; fuel-fired boilers; space heaters with pilot lights or open flames; kerosene heaters; wood stoves; fireplaces; stoves, ovens dryers, water heaters and refrigerators that use gas or liquid fuel; garages; and other motor vehicle-related occupancies. (Effective date: December 28, 2010)

Fire Code New York State §610: 
CO detectors are required in multiple occupancies, including, but not limited to, hotels/motels; apartment buildings; dormitories; adult/child care facilities; assisted living facilities; alcohol/drug centers; convalescent facilities; day care facilities; and certain educational occupancies. (Effective date: December 28, 2010)