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IRC Accessory Structure Proposed Interpretation 23-12

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righter101

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Hey everyone. I was gone for a few weeks, I will have to scan the boards to see what I missed. Hope all is well.

THE ICC has a proposed committee interpretation #23-12 (You can't access it directly from the ICC site unless you are a member.) But I will post it here.

They are taking public comment until Thursday. I just wanted to see what everyone's opinion on this was.

ACCESSORY STRUCTURE. A structure not greater than 3,000 square feet (279 m2) in floor area, and not over two stories in height, the use of which is customarily accessory to and incidental to that of the dwelling(s) and which is located on the same lot.

QUESTION: Is the floor area limitation of 3,000 square feet the combined floor area of all stories above grade plane plus any basement floor area?

ANSWER: (Proposed by committed): No. The floor area limitaiton is per story. The floor area is not the combined floor area of all the stories, it is the area pler story. Each story, including the basemetn, of the accessory structure could be 3,000 square feet.

This is their draft proposal. We (our jurisdiction) has already weighed in on this. This interpreation would allow creation of up to 9000 square foot garages/accessory structures.

Curious what others think about this. If you are an ICC member, there is still time to provide feedback.

Thanks
 
If your jurisdiction has a problem with the maximum size why don't you just restrict them by local law. Here in Canada our code does not restrict accessory structures at all (unlimited size and storeys), but our local laws restrict height and size.

I do have a problem of the use of the word "customarily" in that definition as you could have a "accessory" building that is not accessory of incidental to the use which would (according to our code) make it a major occupancy.
 
From an enforcement standpoint, I am not a big fan of residential accessory structures larger than the main structure, as they don't fit in with our proposed residential comprehensive development plan or our existing zoning regulations, but then again we didn't adopt the IZC either. The largest detached residential garage we have constructed in our ETJ is 7,000 sf, and the largest attached is roughly 3,500 sf.

I can however see circumstances where they may be applicable, as with rural acreage lots, where specialized equipment and recreational indoor vehicle storage may be desired.
 
I think they have rocks in their heads. Should be a max of 3,000 square feet total. An accessory building should be just that. It certainly should not be the domaintant structure.
 
That was my thinking. we have always interpreted it to mean a total of 3,000 sq.ft., not per floor.

We would welcome permit applications for something larger, as it could be constructed under the provisions of the IBC for a U or S2, depending on the use.

Chapter 4 (IBC) has some specific limits on private garages, this appears to be contrary to all that.
 
I don't necessarily agree with the interpretation, but it would get kicked here anyway under zoning code.
 
I think that accessory structures should be left as part of zoning. Putting size limits in the IRC is silly, IMO.
 
The IRC is quit clear in that it has always been per floor area which would be per story. Zoning is the place to limit the size of accessory structures on residential property. Out in the country large shops or barns are common and the majority are truly accessory to the property they are located on.
 
I'm guessing this means that an accessory structure less than 3000 SF per story can be constructed under the IRC. Any larger and it falls under the IBC. I don't think there is any intent to trump zoning restrictions.
 
The definition of an accessory structure in the 2009IRC. A structure not greater than 3000 square feet in floor area, and not over two-stories in height, the use of which is customarily accessory to and incidental to that of the dwellings and which is located on the same lot.

3,000 square feet of floor area / not over two-stories in height.

That could be 3,000 square feet on one floor. 1,500 square feet on two floors. 2,000 square feet down and 1,000 square feet up.

It does not say 3,000 square feet on each of two floors. It does not say a 3,000 square footprint. it says 3,000 square feet of floor area, period.
 
That was my take on it also Big Mac.........but, I've been wrong before.

Like I said, haven't had to waste time on it, Planning would kill anything that size. Max 60% of primary structure, and can not be taller than primary structure. We don't have McMansions here.
 
Big Mac said:
The definition of an accessory structure in the 2009IRC. A structure not greater than 3000 square feet in floor area, and not over two-stories in height, the use of which is customarily accessory to and incidental to that of the dwellings and which is located on the same lot.3,000 square feet of floor area / not over two-stories in height.

That could be 3,000 square feet on one floor. 1,500 square feet on two floors. 2,000 square feet down and 1,000 square feet up.

It does not say 3,000 square feet on each of two floors. It does not say a 3,000 square footprint. it says 3,000 square feet of floor area, period.
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I see your point. It would be nice if they had said "aggregate floor area" if that is what the intent is.

Basements have never been include in the area of a building.

Agree with Paul Sweet if over 3,000 sq ft it falls under the IBC. The IRC does not limit the size of the accessory structure it is just out of the IRC prescriptive requirements.
 
Thanks Big Mac. That summarizes things very well. Makes sense to everyone here. The only one that needs convincing is the ICC. I was a bit shocked to see their response on their draft interpretation.

We have some large garages and barns here. If you want to exceed the 3000 sq ft. we allow it under the IBC.

Thanks for the feedback.
 
mtlogcabin said:
I see your point. It would be nice if they had said "aggregate floor area" if that is what the intent is.Basements have never been include in the area of a building.

Agree with Paul Sweet if over 3,000 sq ft it falls under the IBC. The IRC does not limit the size of the accessory structure it is just out of the IRC prescriptive requirements.
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Not sure what you mean by basements have never been included in the area of a building. If they are below grade, they don't count as a story, but they definately are counted as area.

If I have a 2000 square foot house on top of a 2000 square foot finished basement, I have a 4000 square foot house.

Also, the IRC does limit the accessory size to 3000 square feet. What I was trying to do is get people's opinion if that means per floor or total, as the ICC is preparing an opinion that it is per floor not aggegrate.
 
Yes we get larger outbuildings here too, but they are reviewed using the IBC. Sometimes even Appendix 'C', depending on use.
 
Not sure what you mean by basements have never been included in the area of a building. If they are below grade, they don't count as a story, but they definately are counted as area.
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I was thinking of the IBC. You are correct the IRC is silent on defining building areas

506.5 Mixed occupancy area determination.

The total allowable building area for buildings containing mixed occupancies shall be determined in accordance with the applicable provisions of this section. A single basement need not be included in the total allowable building area , provided such basement does not exceed the area permitted for a building with no more than one story above grade plane .
 
Our pal peach serves on one of the interp committees.......

Or did anyways.....after looking at the roster.
 
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