I am looking to create a finished space in my basement. The plans are for a habitable room within my basement (non-sleeping) to be used as an office. The plans exceed horizontal width requirements, and the ceiling exceeds 7ft. Contained within the room is a 32 x 15.5 inch egress window that was one of two such egresses installed original to the house. I have attached a rough drawing of the proposed layout.
However, my plans were sent back to me by the local planning office (I'm in Western NY) as needing to be modified due to being out of compliance with the following code rules of the 2018 IRC:
R303.1 Habitable rooms.
Habitable rooms shall have an aggregate glazing area of not less than 8 percent of the floor area of such rooms. Natural ventilation shall be through windows, skylights, doors, louvers or other approved openings to the outdoor air. Such openings shall be provided with ready access or shall otherwise be readily controllable by the building occupants. The openable area to the outdoors shall be not less than 4 percent of the floor area being ventilated.
1.The glazed areas need not be openable where the opening is not required by Section R310 and a whole-house mechanical ventilation system is installed in accordance with Section M1505.
2.The glazed areas need not be installed in rooms where Exception 1 is satisfied and artificial light is provided that is capable of producing an average illumination of 6 footcandles (65 lux) over the area of the room at a height of 30 inches (762 mm) above the floor level.
3.Use of sunroom and patio covers, as defined in Section R202, shall be permitted for natural ventilation if in excess of 40 percent of the exterior sunroom walls are open, or are enclosed only by insect screening.
R310.1 Emergency escape and rescue opening required.
Basements, habitable attics and every sleeping room shall have not less than one operable emergency escape and rescue opening. Where basements contain one or more sleeping rooms, an emergency escape and rescue opening shall be required in each sleeping room. Emergency escape and rescue openings shall open directly into a public way, or to a yard or court that opens to a public way.
R305.1 Minimum height.
Habitable space, hallways and portions of basements containing these spaces shall have a ceiling height of not less than 7 feet (2134 mm). Bathrooms, toilet rooms and laundry rooms shall have a ceiling height of not less than 6 feet 8 inches (2032 mm).
1.For rooms with sloped ceilings, the required floor area of the room shall have a ceiling height of not less than 5 feet (1524 mm) and not less than 50 percent of the required floor area shall have a ceiling height of not less than 7 feet (2134 mm).
2.The ceiling height above bathroom and toilet room fixtures shall be such that the fixture is capable of being used for its intended purpose. A shower or tub equipped with a showerhead shall have a ceiling height of not less than 6 feet 8 inches (2032 mm) above an area of not less than 30 inches (762 mm) by 30 inches (762 mm) at the showerhead.
3.Beams, girders, ducts or other obstructions in basements containing habitable space shall be permitted to project to within 6 feet 4 inches (1931 mm) of the finished floor.
To the best of my understanding, my plans as they stand should comply so long as:
- I have mechanical ventilation installed in the new room in accordance with M1505
- Lighting that conforms to the standards laid out in Exception 2 of R303.1
- A ceiling height that conforms to, or exceeds, the height minimum set out in R305.1 (which I do, ceiling height is 7ft 10")
Because I have another egress window in the basement and mechanical ventilation system installed, I meet exception 1 of R303.1, and because I plan to install lighting that will meet the standards of Exception 2 of R303.1, which to me indicates that the egress window in the proposed office space is not required.
However, given that the window is indeed there already, must this window conform to R303.1 simply by existing? Can I meet the requirements of exceptions 1 and 2, but still have the window in place, meaning it is not a code consideration?
This is my best understanding of it as it is worded, however I wanted to get some additional opinions.
Update 1: The building inspector got back to me and confirmed that the window would be taken out of consideration for compliance if Exceptions 1 and 2 were met, however I would need to accommodate a means to get fresh air into the habitable space given the lack of an openable window as far as the inspection would be concerned. A fresh air mixing box attached to the air return would be deemed acceptable in this case.