Section 410.530 - Weather-tight Elements(A) An exterior openable window shall be considered weathertight only when: (1) All panes of glass are in place, unbroken and properly sealed;(2) The window sash opens and closes fully without excessive effort; and(3) One of the following conditions is met: (a) The window sash is sufficiently well-fitted such that it minimizes the infiltration of air or moisture and the space between the window sash and the prime window frame is no larger than 1/8 inch at any point on the perimeter of the sash in the case of double hung windows and 1/16 inch in the case of casement windows; or(b) A storm window is affixed to the prime window frame in such a way as to minimize the infiltration of air or moisture.(B) A door leading from a residence or dwelling unit to the exterior shall be considered to be weathertight only if: (1) All panes of glass are in place, unbroken and properly sealed;(2) The door opens and closes fully without excessive effort; and(3) One of the following conditions is met: (a) The door is sufficiently well-fitted so that it minimizes the infiltration of air or moisture and the space between the door and the prime door frame is no larger than 1/8 inch at any point on the sides of the door; or(b) storm door is affixed to the prime door frame in such a way as to minimize the infiltration of air or moisture.(C) Building and structural elements shall be considered weather-tight when all cracks and spaces not part of heating, ventilating, or air conditioning systems are sealed to prevent infiltration of exterior air or moisture.Adopted by Mass Register Issue 1495, eff. 5/12/2023.