Hi all -
I read through several previous posts on this topic and didn't see exactly what I was looking for, as this portion of IRC was thoroughly updated for 2021.
I'm looking for clarity or correction, specifically pertaining to the provisions for a habitable attic NOT constituting a story (the 326.3 Exceptions).
I'm designing a habitable attic above a 2 story residence, and due to local zoning code, it's imperative that the residence be considered 2 stories based on IRC's criteria.
The terminology in question is found in Exception 1 & 1.1:
"The aggregate area of the habitable attic is either of the following: Not greater than one-third of the floor area of the story below."
Of those three bolded terms, the only one is directly defined by Chapter 2: "habitable attic": A finished or unfinished habitable space within an attic.
And "habitable space": A space in a building for living, sleeping, eating or cooking. Bathrooms, toilet rooms, closets, halls, storage or utility spaces and similar areas are not considered habitable spaces.
Based on this, I believe that when I sum the 'aggregate area' of my 'habitable attic', I'm only totaling up 'habitable spaces'. I will omit stairs, halls, baths, closets, etc.
And it is that 'habitable space' total that needs to be less than 1/3 of the 'floor area' of the story below, to avoid being counted as a story. (along with meeting the rest of the exceptions listed)
First, I welcome any feedback on that reading. I want to make sure I'm not missing something & being overly aggressive with that interpretation.
Second, "floor area" isn't a defined term, and I'd like to know whether or not to include an inset balcony on the 2nd floor in that floor area total. By 'inset' I mean a corner of the rectangular house plan is carved away, and the balcony is 'tucked-in' under the roof above, rather than projecting out.
IBC would count this as part of its "building area" definition (not surrounded by walls, but included within the horizontal projection of the roof above).
But I haven't been able to find specific guidance on this in IRC.
Many thanks -
I read through several previous posts on this topic and didn't see exactly what I was looking for, as this portion of IRC was thoroughly updated for 2021.
I'm looking for clarity or correction, specifically pertaining to the provisions for a habitable attic NOT constituting a story (the 326.3 Exceptions).
I'm designing a habitable attic above a 2 story residence, and due to local zoning code, it's imperative that the residence be considered 2 stories based on IRC's criteria.
The terminology in question is found in Exception 1 & 1.1:
"The aggregate area of the habitable attic is either of the following: Not greater than one-third of the floor area of the story below."
Of those three bolded terms, the only one is directly defined by Chapter 2: "habitable attic": A finished or unfinished habitable space within an attic.
And "habitable space": A space in a building for living, sleeping, eating or cooking. Bathrooms, toilet rooms, closets, halls, storage or utility spaces and similar areas are not considered habitable spaces.
Based on this, I believe that when I sum the 'aggregate area' of my 'habitable attic', I'm only totaling up 'habitable spaces'. I will omit stairs, halls, baths, closets, etc.
And it is that 'habitable space' total that needs to be less than 1/3 of the 'floor area' of the story below, to avoid being counted as a story. (along with meeting the rest of the exceptions listed)
First, I welcome any feedback on that reading. I want to make sure I'm not missing something & being overly aggressive with that interpretation.
Second, "floor area" isn't a defined term, and I'd like to know whether or not to include an inset balcony on the 2nd floor in that floor area total. By 'inset' I mean a corner of the rectangular house plan is carved away, and the balcony is 'tucked-in' under the roof above, rather than projecting out.
IBC would count this as part of its "building area" definition (not surrounded by walls, but included within the horizontal projection of the roof above).
But I haven't been able to find specific guidance on this in IRC.
Many thanks -