jar546
Forum Coordinator
Here is a summary. Do you see the changes compared to previous cycles?
R325.1.1 Natural Light:
R325.1.1 Natural Light:
- Habitable rooms must have glazed openings (windows, skylights, etc.) with an aggregate area of at least 8% of the floor area of the room.
- These required glazed openings must face directly onto a street, alley, public way, yard, or court on the same lot as the building.
- Exceptions:
- Glazed openings can face into an adjacent roofed porch, deck or patio if the longer side is at least 65% unobstructed and the ceiling height is at least 7 feet.
- Glazed openings can face into an adjacent sunroom.
- No glazed openings are required if artificial lighting provides an average of 6 footcandles over the room area at 30 inches above the floor.
- Eave projections are not considered obstructions for yards or courts.
- Habitable rooms must have openable areas to the outdoors with an aggregate area of at least 4% of the floor area.
- These openings can be windows, skylights, doors, louvers or other approved openings.
- The openings must provide ready access or be readily controllable by the occupants.
- Exceptions:
- Natural ventilation is not required if a whole-house or local mechanical ventilation system meeting certain requirements is installed.
- Required ventilation openings can open into a thermally isolated sunroom, roofed porch, deck or patio if at least 40% of the perimeter is open to the outdoors.
- For a sunroom, the minimum openable area between the room and sunroom, and the sunroom to outdoors, is based on the combined floor area.