§27-2062 Lighting and Ventilation in One- And Two-Family Dwellings

   a.   Required windows. Every living room shall have at least one window open to a street, public place or an open and unobstructed yard, court or other required open space on the same lot as the dwelling.

   b.   Size of windows; substitutes for windows.

      (1)   The total area of all windows in the room shall be at least one-tenth the floor area of such room, or twelve square feet, whichever is greater.

      (2)   Skylights, opening directly to the outer air, transparent or translucent panels or doors, or other natural light transmitting media may be substituted for window openings, subject to the approval of the department, if they provide an equivalent amount of light to that transmitted through the window area required in paragraph one of this subdivision.

      (3)   At least forty-five percent of the required window area, skylight or other openings shall be openable to provide natural ventilation. If a mechanical ventilation system provides forty cubic feet of air per minute, the openable area may be reduced to twenty-five percent.

   c.   Noncomplying rooms.

      (1)   A living room in a oneor two-family dwelling constructed after January first, nineteen hundred thirty-eight which meets the minimum room size requirements of article four of this subchapter but does not comply with subdivision a of this section may not be occupied unless it has a single unbroken opening of not less than sixty square feet into an immediately adjoining room. The adjoining room shall have at least one window opening to the outer air and such window shall be not less than one-tenth of the combined floor area of the room.

      (2)   In a one- or two-family dwelling constructed prior to January first, nineteen hundred thirty-eight, an opening shall be required between a room without a window and an immediately adjoining living room with at least one window. Such opening shall have a minimum size of thirty-two and one-half square feet.