Alcove rooms are prohibited. No room can be subdivided so as to make a dark portion of the room. In every tenement house hereafter erected every room except water closet compartments and bathrooms must have at least one window opening directly upon the street or upon the yard or on a court of the minimum size prescribed by the act. Water closet compartments and bathrooms may have windows opening on vent shafts which do not light or ventilate other rooms or halls. Such vent shafts must be at least twenty square feet in area and not less than four feet in their least dimension, and when the building is more than sixty feet in height, must increase in area three square feet for every twelve feet of increase in the height of the building. Such shafts may not be roofed over, and must be provided with a proper intake of air at the bottom. In all rooms excepting water closets and bathrooms the total window area in each room must be at least one-tenth of the superficial area of the room, and no window must be less than twelve square feet in area between the stop beads; in water closets and bathrooms, however, the windows may not be less than three square feet in area nor less than one foot in width.

Size Of Rooms

In each apartment there must be at least one room containing at least 120 square feet of floor area, and all other rooms shall contain at least seventy square feet of floor area. This does not apply, however, to water closet compartments and bathrooms. All rooms must be not less than nine feet high from the floor to the ceiling.