N.Y.C. Admin. Code § 27-2060: § 27-2060 Lighting and ventilation of living rooms in new law tenements.

a. Required windows. Every living room in a new law tenement shall have a window opening on:

(1) A street, or

(2) A lawful yard or court.

b. Size of windows.

(1) The total area of all windows in the room shall be at least one-tenth the floor area of such room.

(2) Every required window shall be at least twelve square feet.

(3) At least one-half of every required window shall open.

(4) The top of one required window in a room shall be at least seven feet six inches above the floor.

c. Through ventilation.

(1) Every part of a dwelling unit of three rooms or less shall be either within eighteen feet of a street or yard or have a window opening upon a lawful court.

(2) If the window of any room opens on an inner court with a width of less than ten feet between the exterior wall of the dwelling and the lot line, there shall be a sash window connecting such room to an adjoining room within the dwelling unit. The sash window shall have at least ten square feet of glazed area, one-half of which shall open.

d. Dining space. A dining space shall have at least one window:

(1) That complies with the provisions of subdivision a; and

(2) That has an area not less than one-eighth the floor area of such dining space.