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Garage - No Man Door

Yikes said:
(For that matter, does the unamended IRC have any limitations as to the allowable area of either the residence or its accessory uses other than height?)
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Not that I'm aware of. A single family residence can be as large as the owner wants it to be

Yikes said:
Could you hypothetically build a variant of The White House under the the IRC (less than 3 stories above grade, right?) , where the West Wing functions as an accessory structure?
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In my opinion, yes. And this brings up an interesting point: The language and punctuation of IRC section R101.2 is ambiguous. Does the three-story limitation apply to one- and two-family dwellings as well as to townhouses, or only to townhouses? The 2021 IRC Commentary suggests that the limitation applies to all, but my understanding has always been (until I just read that Commentary) that the three-story limitation applied only to townhouses, and that one- and two-family dwellings could be any number of stories.

R101.2 Scope. The provisions of this code shall apply to the
construction, alteration, movement, enlargement, replacement,
repair, equipment, use and occupancy, location, removal and
demolition of detached one- and two-family dwellings and
townhouses not more than three stories above grade plane in
height with a separate means of egress and their accessory
structures not more than three stories above grade plane in
height.
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Doesn't the use of the detached structure in IRC affect the egress requirements? I thought if there was living, sleeping, eating, etc. in it that a person door was required. It's the storage only use that doesn't require MOE. Certainly if there is other activity, like an office, it must have MOE separated from and not through the garage.
 
wwhitney said:
Sure, you can refer to IBC/CBC Chapter 3 to decide based on the use if there are in fact multiple occupancies or not. I'm not so versant with that Chapter, but I imagine your outlier examples would depend on whether the building is used just by the owner and their family, in which case it would be accessory to the one family dwelling and under the IRC. Or whether it is, say, open to the public for tours, in which case it might be a different occupancy which is subject to the IBC.

Interestingly, I noticed under Group U in the IBC it includes "Grain silos, accessory to a residential occupancy." Does that mean I can build a grain silo next to my farmhouse under the provision of the IRC rather than the IBC? Maybe some of the height limits in the IRC would make that impractical.
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I’m not entirely sure either. If someone wanted to build a silo as an accessory structure on their property and zoning approved it, we’d issue the permit—but we’d require an architect or engineer, preferably an engineer.

Since it’s not a commercial building and is just an accessory to the residence, applying the IRC makes sense from a use perspective. However, from a structural standpoint, the IBC might be more appropriate given the nature of the structure. In practice, any engineer would likely follow IBC structural standards regardless, as the IRC doesn't address structures like silos in detail.

The line can get blurry here, but the design requirements will naturally steer the project toward IBC-level structural considerations.
 
bill1952 said:
Doesn't the use of the detached structure in IRC affect the egress requirements? I thought if there was living, sleeping, eating, etc. in it that a person door was required. It's the storage only use that doesn't require MOE. Certainly if there is other activity, like an office, it must have MOE separated from and not through the garage.
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Let's look at that. 2021 IRC:

R311.1 Means of egress. Dwellings shall be provided with a
means of egress in accordance with this section. The means of
egress shall provide a continuous and unobstructed path of
vertical and horizontal egress travel from all portions of the
dwelling to the required egress door without requiring travel
through a garage. The required egress door shall open directly
into a public way or to a yard or court that opens to a public
way.
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A detached garage is an accessory structure, not a dwelling -- unless it gets converted to an ADU, which is beyond the scope of this discussion. The IRC definition of "dwelling" is:

[RB] DWELLING. Any building that contains one or two
dwelling units used, intended, or designed to be built, used,
rented, leased, let or hired out to be occupied, or that are occupied
for living purposes.

[RB] DWELLING UNIT. A single unit providing complete
independent living facilities for one or more persons, including
permanent provisions for living, sleeping, eating, cooking and
sanitation. For the definition applicable in Chapter 11, see
Section N1101.6.
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So a dwelling has to contain at least one dwelling unit, and a dwelling unit has to provide permanent provisions for living, sleeping, eating, cooking and
sanitation. A garage doesn't typically provide permanent provisions for sleeping, eating, cooking and sanitation. So a garage, detached or attached, isn't a dwelling. R311.1 requires only one egress door for each dwelling. There are no requirements for egress doors from accessory structures.

What's an accessory structure?

[RB] ACCESSORY STRUCTURE. A structure that is accessory
to and incidental to that of the dwelling(s) and that is
located on the same lot.
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No size limitations. Several parts of my state have a lot of horse farms. It's not unusual to see large horse barns, complete with indoor riding arenas, built under the IRC as accessory structures. We don't move them to the IBC unless the use will include paid riding instruction and indoor horse shows/competitions. At that point they become commercial enterprises and the use is no longer incidental to the residential use of the house.
 
Have to chase the codes down again, it my be under IRC MA amendment that limits accessor garages to 1000 sf

2015 IBC

406.3.1 Classification
Assembly
Private garages and carports shall be classified as Group U occupancies. Each private garage shall be not greater than 1,000 square feet (93 m2) in area. Multiple private garages are permitted in a building where each private garage is separated from the other private garages by 1-hour fire barriers in accordance with Section 707, or 1-hour horizontal assemblies in accordance with Section 711, or both.
 
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jar546 said:
I’m not entirely sure either. If someone wanted to build a silo as an accessory structure on their property and zoning approved it, we’d issue the permit—but we’d require an architect or engineer, preferably an engineer.
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I fail to understand how a silo would be an ‘accessory’ to a dwelling. That which can be a legitimate accessory to a dwelling is required to have a nexus to a dwelling. Especially when the Residential Code applies to the accessory structure.
 
ICE said:
I fail to understand how a silo would be an ‘accessory’ to a dwelling. That which can be a legitimate accessory to a dwelling is required to have a nexus to a dwelling. Especially when the Residential Code applies to the accessory structure.
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On an owner-operated farm, every structure on the farm is an accessory structure in this corner of the country. I know you are on the diagonally opposite corner, so you may view things differently on the left coast.
 
I don't know what the code says, but the DETACHED garage is not living space, so does not have the same rules as living space. Only one of my 5 detached garages have a "man door". I believe the only requirement is that you be able to open the door manually from inside, such as the emergency release for the garage door. Many of the attached garages in condo's and apartments in California do not have a "man door" only the main garage door, unless the garage is backed up to the unit. I left California in 2009, so I don't know if this changed since then.
 
I have seen homes where the various functions - living, eating, cooking, sleeping, sanitation - are divided in separate structures. Are any of the separate structures either a dwelling or a dwelling unit? Are any or all of them accessory structures?

And the detached garage in the same building with rooms for sleeping or living, is it exempted from the MOE requirements because it's not a dwelling or dwelling unit?
 
TheCommish said:
Have to chase the codes down again, it my be under IRC MA amendment that limits accessor garages to 1000 sf

2015 IBC

406.3.1 Classification
Assembly
Private garages and carports shall be classified as Group U occupancies. Each private garage shall be not greater than 1,000 square feet (93 m2) in area. Multiple private garages are permitted in a building where each private garage is separated from the other private garages by 1-hour fire barriers in accordance with Section 707, or 1-hour horizontal assemblies in accordance with Section 711, or both.
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updated
 
bill1952 said:
I would have sworn this has been discussed here and the consensus was MOE is not required for an accessory structure that is just storage or isn't for habitation. I was surprised.

As an aside, having recently built a detached 2 car garage with a person-door, I wished I'd omitted it. We never use it. Much easier to use extra remotes from house to open or close the overhead doors and not have to walk around to side nor shovel snow. Just how it works for us.
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jar546

Thread 'Egress Door From Garage'

Should an egress door be required from all garages governed under the IRC?
 
Not aware of a requirement for a "man-door" or "walk-out door" on a residential garage attached or non-attached unless the AHJ has made it a requirement.

If required, electrical receptacle and a light at the egress may be required as well.

There are millions of home built in the US without the man-door or walk-out door!

jar546 said:
Should an egress door be required from all garages governed under the IRC?
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If your asking for a code change, It may be something to explore but will add to the cost of construction.
 
jar546 said:
Not asking for a code change. Asking a question that I think may have different opinions.
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We do not have that as a requirement here.

I for one, can't live without the walk-out door from the garage, the dog goes out that door to back yard several times a day.:)
 
Yikes said:
(For that matter, does the unamended IRC have any limitations as to the allowable area of either the residence or its accessory uses other than height?)
Click to expand...
I prefer the 2006 definition

2006 IRC
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.

2018 IRC
[RB] ACCESSORY STRUCTURE. A structure that is accessory to and incidental to that of the dwelling(s) and that is located on the same lot.
 
mtlogcabin said:
I prefer the 2006 definition

2006 IRC
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.

2018 IRC
[RB] ACCESSORY STRUCTURE. A structure that is accessory to and incidental to that of the dwelling(s) and that is located on the same lot.
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Makes you wonder what instigated the change to an unlimited size accessory structure.
 
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