Aircraft hanger

[Sifu]

This could go in either residential or commercial...

Residential development full of SFD's and several private aircraft hangers accessory to the SFD's, 2018 IRC/IBC. Single family dwelling, with a detached (or detached) building used as an aircraft hanger for a tail-dragger. IRC applies to "their accessory structures". So does a 3,000sf² attached garage used for a plane rather than an RV count as a SFD accessory structure?

IBC 412.4 has it's very own section for "residential aircraft hangers", which would limit the size to 2,000sf². However, if it is a residential accessory structure, how does a user even get to the IBC? If it is an IRC accessory structure, then what would an IBC residential aircraft hanger be? Is it accessory to a residential structure that is not a SFD? I think these would be IRC regulated accessory structures, same as an RV garage, but since the IBC has a specific section for residential aircraft hangers I am puzzled. I make the distinction between "private" and "not private", but the code doesn't seem to make the same distinction.

 

[Yankee Chronicler]

IBC section 412.4 has commentaries for each subsection, and they all generally address these structures as accessory to residences, but don't explain how you get from the IRC to the IBC. IBC section 412.4.5 establishes a maximum height of 20 feet and a maximum area of 2,000 s.f. The commentary then mentions the definition in section 202. And the definition has its own commentary:



And the IRC is SO silent on this that it doesn't even include the definition. I think it's a very valid question to ask how we get from the IRC to the IBC for a hangar. The ICC obviously thinks residential hangars are addressed in the IBC. I'm not a lawyer, but I am a writer and editor, and I don' think there's any way to get from the IRC to the IBC for a structure that is accessory to a single-family dwelling.

 

[Sifu]

I don' think there's any way to get from the IRC to the IBC for a structure that is accessory to a single-family dwelling.

This is my thinking. If it under the care and custody, and for use only be the resident, it is an accessory structure to the SFD by the code.

This is not my review, just trying to answer some questions about a reviewer who denied the application based on the IBC. My first reaction was how did they get to the IBC? There are elements of the construction that exceed the limitations of the IRC, so those are appropriately designed to the requirements of the IBC, but I can't connect the use to the IBC.

It does beg the question of what is a residential hanger that would be administered out of the IBC. I looked to the '21 and '24 codes to see if anything else has been done to clarify this but I don't see it. The 2012 IRC limited the size of accessory to 3,000sf², but that was removed, so we get what we get.

Florida has a lot of these fly-in communities so maybe one of our southernmost contributors can chime in.

 

[Joe.B]

Easy. House is IRC. The "Residential Aircraft Hanger" is IBC. Done. Bigger question is zoning. If they say yes, then easy peasy.

 

[Yankee Chronicler]

Easy. House is IRC. The "Residential Aircraft Hanger" is IBC. Done. Bigger question is zoning. If they say yes, then easy peasy.

It's not that easy. The IRC is supposed to cover all one- and two-family dwelling, townhouses, and structures that are accessory to one- and two-family dwellings. How is a private aircraft hangar any different from a private garage (attached or detached)? Both are accessory to the dwelling unit, and both house a motorized vehicle.

It's clear from the IBC commentaries on residential aircraft hangars that the ICC intends such hangars to be regulated by the IBC, but IMHO the authors have forgotten that there has to be a path to get from the primary code to any other code. And I don't find anything in the IRC that even mentions residential aircraft hangars, and there's certainly nothing in the IRC that sends me to the IBC to look for them.

 

[bill1952]

the authors have forgotten

The authors are us and everyone and anyone who participates. It's almost all I do in retirement. ICC, NFPA, and UL currently.

 

[TheCommish]

You don't under the unamend ICC codes have to get from the IRC to the the IBC.

Straight from the ICC website 2021 IBC

[A] 101.2 Scope.
The provisions of this code shall apply to the construction, alteration, relocation, enlargement, replacement, repair, equipment, use and occupancy, location, maintenance, removal and demolition of every building or structure or any appurtenances connected or attached to such buildings or structures.

Exception: 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, shall comply with this code or the International Residential Code.

In MA we have the same language. I look at Connecticut and they admen the language and remove the word or.

Exception: Detached one- and two-family dwellings and multiple single-family dwellings (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, shall comply with the 2021 International Residential Code portion of the 2022 Connecticut State Building Code.

In my world, Charlton MA, and the whole state since we have one state wide code you can design SFH and accessory structures either by using the IBC, or the IRC and if the design is not covered by the IRC you have to fall back to the IBC provisions.

My understanding of the 2 separate codes it the is to have a singe volume that jurisdictions may adopt the containing all the codes needed to build SFM, Duplexes and townhomes with electrical and plumbing included. Additionally reliving the SFH side from have to sort though all the more complex issues of the IBC.

 

[Yankee Chronicler]

You don't under the unamend ICC codes have to get from the IRC to the the IBC.

You still need a code path.

We have always been allowed to build houses under the IBC, and (in my corner of the country) before the ICC we could build houses using the BOCA Basic Building Code. But virtually nobody ever does that. So, unless the permit for a house says it was designed under the IBC, the presumption would have to be that it's designed under the IRC, and the plans probably state that.

Once you open the IRC to design the house, the IRC also applies to accessory structures. If someone with a single family house came to you with an application to build a 2-car detached garage, would you tell them they have to use the IBC? Probably not. So why would you tell them to use the IBC for an airplane garage?

Absent a specific reference in the IRC, there's simply no way to get to the IBC. They ("we") didn't even repeat the definition in the IRC.

In the opening question, the hangar is 3,000 s.f., and the definition of a residential aircraft hangar limits it to 2,000 s.f. My view is, "So what?" I'm in the IRC -- I don't need to look in the IBC at all. I can build a 30,000 s.f. home under the IRC. I can build a 300,000 s.f home under the IRC. Why can't I build a 3,000 s.f. accessory building under the IRC? Where does the IRC say I can't?

 

[Inspector Gadget]

There's an NFPA standard for aircraft hangers - 409 Double-check to see if that's empowered in this case.

 

[Yankee Chronicler]

There's an NFPA standard for aircraft hangers - 409 Double-check to see if that's empowered in this case.

That may depend on the jurisdiction. In this state, fire marshals generally don't have anything to do with single-family properties.

NFPA 409 is not a referenced standard in the IRC. No code path to get to it.

 

[Sifu]

If I could figure out what a residential aircraft hanger administered out of the IBC would be it might be easier to make the determination. It seems that the IBC residential hanger would be accessory to and incidental to IBC residential occupancies. Of these the only one that is seen as equivalent to the IRC/SFD would be R3. So a single family home, designed in accordance with the IBC as an R3 can have a residential aircraft hanger up to 2,000sf². A larger one would be an S1, and follow the appropriate paths in the IBC for separation, mixed occupancies, etc. However, I am with Yankee, there is nothing in the IRC that sends us to the IBC, or makes the SFD an R3. The IRC says the provisions of the IRC shall apply to accessory structures. Accessory structures are defined in the IRC as accessory to and incidental to the SFD and located on the same lot. I fail to see how it is not an accessory structure to the SFD, at least the way the code is written. Maybe that is not the intent, maybe it is. But in the absence of clear, validated intent I have a hard time tying the use to the IBC. It seems like code correlation missed this one unless we take the code at face value....that a residential aircraft hanger administered out of the IBC is applicable to residential occupancies administered out of the IBC.

 

[mtlogcabin]

And I don't find anything in the IRC that even mentions residential aircraft hangars, and there's certainly nothing in the IRC that sends me to the IBC to look for them.

And the IRC is SO silent on this that it doesn't even include the definition

R201.3 Terms defined in other codes.
Where terms are not defined in this code such terms shall have the meanings ascribed in other code publications of the International Code Council.

Effective Use of the International Residential Code
In other words, the IRC is meant to be all inclusive for typical residential construction and it relies on other codes only where alternatives are desired or where the code lacks coverage for the uncommon aspect of residential construction.

 

[Joe.B]

 

[Joe.B]

My friend rents the house portion of this "building" which was built by friends of his parents. The guy bought the lot (in blue) in order to build his private aircraft hangar that has access to the airstrip at the top of the photo. The local zoning department said the property was zoned residential and they couldn't have the aircraft hangar without the house. No problem, add a house which has access to the street at the bottom of the photo.

I was curious about this when I was visiting, and it happened that the owner was there working on his plane, so we went back and asked him. These were designed as two separate buildings (red line) to satisfy building code, built "touching" to satisfy zoning code. In the eyes of the zoning administrator, this is an SFR with an attached "accessory building". In the eyes of the building official (who doesn't give a hoot what zoning calls it) these are two separate buildings. The house is absolutely a residential code design and build, the hangar is absolutely a building code design and build.

I see no conflicts.

 

[BN4537]

R101.2​

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.

Exception: The following shall be permitted to be constructed in accordance with this code where provided with an automatic sprinkler system complying with Section P2904:

1. Live/work units located in townhouses and complying with the requirements of Section 508.5 of the International Building Code.
2. Owner-occupied lodging houses with five or fewer guestrooms.
3. A care facility with five or fewer persons receiving custodial care within a dwelling unit.
4. A care facility with five or fewer persons receiving medical care within a dwelling unit.
5. A care facility for five or fewer persons receiving care that are within a single-family dwelling.

[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.

accessory​

noun​

ac·ces·so·ry ik-ˈse-sə-rē
: an object or device that is not essential in itself but adds to the beauty, convenience, or effectiveness of something else
auto accessories

incidental​

adjective​

in·ci·den·tal ˌin(t)-sə-ˈden-tᵊl

: being likely to ensue as a chance or minor consequence
social obligations incidental to the job

Is the aircraft hanger accessory to the house? I would say yes if it's only used by the owner for his toys; it's not essential but it does add convenience. Is it incidental? I think, again, if it's only for personal use it is of minor consequence and therefore incidental. Obviously it's on the same lot, or we would not be having this discussion.

My opinion is that it is perfectly reasonable to assert that the hanger is just an IRC accessory structure if it is for personal use only and on the same lot as an IRC dwelling.

 

[steveray]

IBC section 412.4 has commentaries for each subsection, and they all generally address these structures as accessory to residences, but don't explain how you get from the IRC to the IBC. IBC section 412.4.5 establishes a maximum height of 20 feet and a maximum area of 2,000 s.f. The commentary then mentions the definition in section 202. And the definition has its own commentary:

View attachment 14708

And the IRC is SO silent on this that it doesn't even include the definition. I think it's a very valid question to ask how we get from the IRC to the IBC for a hangar. The ICC obviously thinks residential hangars are addressed in the IBC. I'm not a lawyer, but I am a writer and editor, and I don' think there's any way to get from the IRC to the IBC for a structure that is accessory to a single-family dwelling.

R201.3​

Where terms are not defined in this code such terms shall have the meanings ascribed in other code publications of the International Code Council.

I believe they were trying to "fix" this in 24 or 27, but I don't see it in 24......I remember seeing a bunch or proposals benefitting people with private planes but I need to install occupancy sensors in my house.....