treehouse

[bill1952]

A client of my son wants him to build a treehouse as a air BNB. On owners home property so an accessory structure. I seem to recall in NY - and I'll look it up - but 150 SF does not require a permit. If it does require a permit, can a tree qualify as a foundation?

And if it is exempt from permit, it still has to meet all the code requirements, correct?

Thanks.

 

[Yikes]

Sherman Oaks treehouse demolished after battle with the city​

BY LA Times Today Staff Sherman Oaks
PUBLISHED 10:59 AM PT Mar. 13, 2025

For nearly 25 years, a treehouse stood in a Sherman Oaks neighborhood. It was built by an ex-producer of “The Simpson’s.” The treehouse was a beloved attraction for family and neighbors that was affectionately dubbed Boney Island during Halloween. For years, the city of LA fought to tear it down. The man behind the treehouse, Rick Polizzi, shared how it feels to demolish it.

Polizzi started creating the Boney Island Halloween display in 1997. The event attracted hundreds of visitors each year. He and fellow “Simpsons” producer Michael Mahan added the treehouse to the display a few years later.

“We just kept adding walls here and there until it became a nice little structure. I’m from New Orleans and pretty sociable down there, and I feel in Los Angeles, [people] keep to themselves. And so I was always trying to do something to get the neighbors to come out and hang out, come over. That’s why I did the Halloween display,” Polizzi explained. “We were a victim of our own success because it got so crowded we had to hire traffic control. One neighbor across the street always hated it, and constantly calling the police and complaining, and then called the city on the tree house.”

In 2017, Polizzi’s neighbor told the city that he was running a business in the treehouse. When the city inspected it, they inquired about Polizzi’s permit. He didn’t have one, and a long legal saga began.

“Once it gets in that City Hall system, I run into the red tape, the bureaucracy. And it was just seven years of banging your head against the wall and nothing ever happened. We got the zoning, but we don’t have the building permits, and they are calling it an ADU. And I’m saying it’s not an ADU. It’s under 120 square feet. And they just are saying, no, you’re going to need geological samples. You’re going to have to have surveys, architectural drawings, structural engineering drawings,” Polizzi said.

All of those things would have cost Polizzi tens of thousands of dollars, on top of lawyer and court fees. He decided it was time for the treehouse to come down. Polizzi explained that “the city wins” on this issue.

“This wasn’t really hurting anyone. It had been up for 24 years. Never an incident. It just seems like you’d be able to soften the permitting for something like this. But I just never could get guidance from building and safety. And it was more legal fees, and we’re taking it to court. And the average citizen just has to give up,” he said.

Polizzi says he does not have any plans to rebuild the treehouse at this time.

 

[Yankee Chronicler]

It's difficult to know what any local AHJ might do regarding a kids' treehouse that's just a play structure. Once it becomes a commercial enterprise, subject to residential occupancy, my inclination would be to say that it has to meet code.

A tree big enough to support an Air B&B probably has roots deep enough to go below the frost line. Who knows if an AHJ would accept that, though ...

 

[e hilton]

Does an airbnb require a basic kitchen and bath? 150 sf is not large.

 

[bill1952]

I was trying to see how the exemption of frost protection for 600 SF detached accessory structures might fit. Was looking for definition of eave heigth measurement when building is not on the ground.

150 SF is tight, not sure kitchen is required. the IRC 200 SF makes it more possible.

Thanks all!

 

[Yikes]

I think that a plan checker shall never see
A foundation as inscrutable as a tree.

 

[steveray]

The irc permit exemption is storage sheds, playground structures and similar….not buildings people sleep in…

 

[bill1952]

The irc permit exemption is storage sheds, playground structures and similar….not buildings people sleep in…

You're saying you can't sleep in "A structure that is accessory to and incidental to that of the dwelling(s) or townhouse(s) and that is located on the same lot." ?

Seems to be a jurisdictional issue, not IRC, and ADUs seem exempt, perhaps again on a jurisdictional basis.

So can an ADU be used for short term rental? Seems it can, at least in NY.

 

[Mr. Inspector]

The roots would have to be treated for in ground use

 

[Yankee Chronicler]

You're saying you can't sleep in "A structure that is accessory to and incidental to that of the dwelling(s) or townhouse(s) and that is located on the same lot." ?

Seems to be a jurisdictional issue, not IRC, and ADUs seem exempt, perhaps again on a jurisdictional basis.

So can an ADU be used for short term rental? Seems it can, at least in NY.

Classic example of "Give 'em an inch and they'll take a mile."

The push fior ADUs is intended to address the [purported] housing shortage. Using an "ADU" as a short-term Air B&B doesn't in any way contribute to creating more places for people with limited incomes to live. This is a sociological/political issue, not a building code issue, but it is part of the discussion.

 

[bill1952]

The roots would have to be treated for in ground use

naturally decay resistant - as long as tree is allive

 

[bill1952]

Classic example of "Give 'em an inch and they'll take a mile."

The push fior ADUs is intended to address the [purported] housing shortage. Using an "ADU" as a short-term Air B&B doesn't in any way contribute to creating more places for people with limited incomes to live. This is a sociological/political issue, not a building code issue, but it is part of the discussion.

To begin with, there are many treehouses that are short term rentals.

Courtesy of a member here: https://shorturl.at/vvkpD

Your take on ADUs, not the code's. I don't see ADUs as related to income And you're conflating an ownership question with safety.

 

[steveray]

You're saying you can't sleep in "A structure that is accessory to and incidental to that of the dwelling(s) or townhouse(s) and that is located on the same lot." ?

Seems to be a jurisdictional issue, not IRC, and ADUs seem exempt, perhaps again on a jurisdictional basis.

So can an ADU be used for short term rental? Seems it can, at least in NY.

I am saying there is a difference between a dwelling unit and an "other than dwelling unit"....(My sparky friends would be so proud...)

 

[bill1952]

It's not defined as "other than a dwelling unit" but as "incidental to". The fifth bedroom of a 4 bedroom dwelling seems incidental to me.

incidental definitions:
a minor part
accompanying but not a major part
less important than the thing something is
connected to
subordinate or secondary in importance

This is a group that generally says enforce the words of the code but clearly personal beliefs are in play here.

 

[steveray]

If it is living space, it is part of the dwelling unit or it's own dwelling unit.....Unless you want to believe that I can build a 2000ft house next to a 5000ft house and not meet code in the 2000 because it is accessory....

 

[bill1952]

All I said was if 600 and under the foundation of an accessory structure doesn't have to be frost protected. Exceptions 1 and 2. Everything else in the accessory unit has to meet code, regardless whether it's for an ADU or other dwelling purposes or a garage or rabbit hutch or whatever. Never a question of it not meeting code. I don't know what your jurisdiction says but NY it seems quite clear ADUs are accessory structures and can be short term rentals and if 600 SF and under the foundation does not have to be frost protected. From a safety perspective, what's the code issue? I can tell you don't personally approve.

R403.1.4.1​

Except where otherwise protected from frost, foundation walls, piers and other permanent supports of buildings and structures shall be protected from frost by one or more of the following methods:

1. 1.Extended below the frost line specified in Table R301.2.
2. 2.Constructed in accordance with Section R403.3.
3. 3.Constructed in accordance with ASCE 32.
4. 4.Erected on solid rock.

Footings shall not bear on frozen soil unless the frozen condition is permanent.

Exceptions:

1. Protection of free-standing accessory structures with an area of 600 square feet (56 m2) or less, of light-frame construction, with an eave height of 10 feet (3048 mm) or less shall not be required.
2. Protection of free-standing accessory structures with an area of 400 square feet (37 m2) or less, of other than light-frame construction, with an eave height of 10 feet (3048 mm) or less shall not be required.

 

[steveray]

From a safety perspective, what's the code issue? I can tell you don't personally approve.

Energy code, egress, ungraded lumber, and it's transient so it is R1.....Sprinklers?

 

[SCBO1]

Does your insurance company's liability kicks in if one of the neighbors kids fall out of tree house and becomes paraplegic.

Lawyer up!

 

[bill1952]

I never said it didn't have to meet codes, energy and all. As far as sprinklers, there are thousands of short term rentals without sprinklers. CO and smoke detectors yes. Maybe fire extinguisher. If sprinklers are required, a lot of jurisdictions are doing a terrible job of code enforcement. And quite a few short term rentals called tree houses.

Well, I NY ungraded lumber is permitted. A lot of the tree house short term rentals on line seem to be more of an accessory dwelling on stilts, so not relying on tree for foundation. I can accept not everyone would call a house on stilts amongst trees a tree house, but a lot of people do.

Yes, it would make sense to have short term rental insurance. I've never been a landlord but assume people who rent property should have liability insurance. Someone can get heart in a one story slab on ground as easily as in a treehouse.

 

[wwhitney]

it seems quite clear ADUs are accessory structures

You haven't given the applicable definition of ADU, but assuming it includes being a dwelling, then I would say no, ADUs are not accessory structures.

The definition of accessory structure you gave is "A structure that is accessory to and incidental to that of the dwelling(s) or townhouse(s) and that is located on the same lot." So for a dwelling like an ADU, calling it an accessory structure would mean calling it "accessory to and incidental to" itself, since it is one of the dwelling(s). That doesn't make sense.

Now if the text in the definition of accessory structure were something like "accessory to and incidental to the primary dwelling," then sure an ADU could be an accessory structure.

Cheers, Wayne

 

[bill1952]

Not seeing your distinction between definitions. My quoted definition was cut and pasted from 25 IRC. If there is a dwelling unit on the lot, I don't see anything in the IRC preventing there being an accessory structure used as an accessory dwelling unit.

There are tens of thousands of short term rentals in accessory structures. Maybe you're saying they are not ADUs, but failing to see the difference.

Jurisdictional zoning and other ordinances may affect compliance.

I think we can see that a structure above grade and amongst trees can be code compliant. The only issue is if the 600 SF exception applies for frost protection.

I don't find anything in the IRC or by searching online that says an accessory dwelling unit can't be an IRC accessory structure, and comply fully with the IRC. Appendix BC is clear it can be a "detached structure".

 

[wwhitney]

Not seeing your distinction between definitions. My quoted definition was cut and pasted from 25 IRC. If there is a dwelling unit on the lot, I don't see anything in the IRC preventing there being an accessory structure used as an accessory dwelling unit.

Say you have a main house and an ADU as separate structures on a lot. That's two dwellings, yes?.

Then let's apply the definition of "accessory structure" you provided. We can substitute in the identity of the "dwelling(s)" for this property, and the definition becomes "A structure that is accessory to and incidental to the main house and the ADU and that is located on the same lot."

That plainly means the accessory structure has to be a structure that is not the main house and is not the ADU. Dwellings can never be accessory structures under this definition of "accessory structure".

No opinion on any of the other questions raised in this thread, I just enjoy parsing definitions. : - )

Cheers, Wayne

 

[steveray]

If it was engineered I could get on board with an IRC structure in a tree....But it would have to meet the IRC...

 

[bill1952]

Say you have a main house and an ADU as separate structures on a lot. That's two dwellings, yes?.

Then let's apply the definition of "accessory structure" you provided. We can substitute in the identity of the "dwelling(s)" for this property, and the definition becomes "A structure that is accessory to and incidental to the main house and the ADU and that is located on the same lot."

That plainly means the accessory structure has to be a structure that is not the main house and is not the ADU. Dwellings can never be accessory structures under this definition of "accessory structure".

No opinion on any of the other questions raised in this thread, I just enjoy parsing definitions. : - )

Cheers, Wayne

So if zoning does not allow 2 separate dwelling units on a lot, and ADU is not permitted?

So even just a bunk house - a bedroom by another name - is not in your view and accessory structure and if under 600 SF would have to have a frost protected foundation?

I feel this is not worked out in the codes.