How The Small Residential Unit Could Negatively Impact Tiny Houses
The ICC OSMTH 1215 committee is currently developing a standard called ICC/THIA 1215 – 202x Design, Construction and Regulation of Tiny Houses for Permanent Occupancy. The standard is being developed by the OSMTH 1215 Committee and ICC is co-branding the standard with the Tiny Home Industry Association ( THIA). I have linked the initial press release below that will give you a clear picture about the purpose and the intent of the standard. The purpose was to advance tiny houses and finally add chassis provisions to be adopted into the 2027 IRC. The focus was suppose to be about tiny houses, but instead it became hijacked by the Small Residential Unit.
For More Back Story And Context: Start With This Blog Post First
Small Residential Unit Hijacking Tiny Houses In OSMTH 1215
If you have not been following my blog posts regarding the OSMTH 1215 committee, start at this blog first that is linked below to get up to speed and come back to this one. I have been participating for over a year as an interested party. I have attended the calls and made public comments. I will continue to write in this blog post as if you have been brought up to current events.
Link To Small Residential Unit Hijacking Tiny Houses In OSMTH 1215
How Would The Small Residential Unit Be Negative For Tiny Houses?
I have been asked that question a lot in the last few days and I feel I can better answer this. There has been a great debate in the OSMTH 1215 committee regarding the Small Residential Unit takeover of the standard which is the agenda of ICC. They want to position the Small Residential Unit, a made up term that is not used by anyone and is not enforceable over Tiny Houses, a codified term in the IRC, making Tiny Houses a subcategory under the Small Residential Unit.
I submitted a PINS complaint to ICC after ICC announced a new revised PINS in ANSI Standards Action on May 16, 2025 that added the Small Residential Unit to the title and the scope of the standard, and today I sent an addendum to add to my complaint.
Highlights Of Addendum To My PINS Complaint
On the last call we were discussing the chassis and NHTSA requirements and there were some opposing views, so after the call, I emailed the committee, and we shared a few thoughts on the topic
The Crux Of The Matter
The email exchange that revealed the crux of the matter and a great disconnect regarding the intention of the standard. I have suggested a work group on the topic of the chassis.
The original intent of the standard was to finally address the immediate need for the tiny house industry, to add provisions for tiny houses on wheels, including chassis provisions, to be adopted into the IRC, recognized as a housing type, resulting into financing for tiny houses on wheels, one of our number one barriers for the tiny house industry.
Tiny houses on wheels are built on prefabricated trailers, or the builders are building the trailers themself, and owner builders are allowed to build homemade trailers in some states. The structure is integrated to the trailer usually in a permanent manner and the axles and tires stay on after they are transported to their destination, unless an AHJ asks for the axles to be removed.
The Disconnect: The Transport Method As Opposed To A Permanent Chassis
How a few voting members interpret a tiny house on wheels to be is a modular structure built off site and transported on a carrier system. It could be a frame on or off. When it is sited, in both cases, the axles are removed, and with the frame on, the I-Beams are still intact.
That is not a tiny house on wheels, and it is not even a wheeled structure. It is a module transported on a carrier system and it is my understanding that the Modular manufacturers use certified recycled axles from manufactured homes for a one time use that are removed before they are sited on a foundation, so in reality it is a tiny home on a foundation, not a tiny house on wheels.
Now that I understand how some of the voting members interpret a tiny house on wheels, it clarifies it even more that there is no need for the standard at all in the direction it is going because frame on and frame off Modular homes have already existed for over 60 years and longer. The Small Residential Unit will even complicate both the Modular And Manufactured Home industry and that is why stakeholders from those industries should be notified. They are the ones already building a Small Residential Unit, without using the new name.
The Small Residential Unit is also putting limitations on the structures regarding size including width and lengths in the standard which have already been determined for decades.
The Small Residential Unit delivered on a carrier system seems to be replacing tiny homes on wheels, though in reality it is a tiny house on a foundation.
Negative Impact
- If the standard stays in the direction of the Small Residential Unit with a carrier system for transport, ( As The Committee’s Interpretation For A Tiny House On Wheels) this will negatively impact trailer manufacturers that supply trailers for tiny home builders and will give the business to the transport carriers.
- This will also impact tiny home builders that build tiny homes on wheels on a permanent chassis that could negatively impact their business, because the carrier system used by large manufacturers could dominate the tiny house industry and squeeze out small manufacturers.
- The carrier system is a great method, but it will mainly be used for individuals that own land, this could harm the owner builder and consumer because they often cannot afford to buy both land and the tiny home, so they choose the tiny home on wheels that they could permanently place on leased property, though they still need for it to be mobile, in case they sell it, or move in the future, or if a community is sold, or if the space rent becomes unaffordable.
- This could impact transport companies that deliver tiny houses on wheels, if all the business is directed to the transport carriers.
- The small manufacturer would be squeezed out if they have to buy a carrier system for transportation to compete.
- The Small Residential Unit will stifle the growth for anyone that is in the tiny house industry, including third party agencies, designers, components for the chassis, etc……
- The Small Residential Unit will stop the growth and progress for tiny houses on wheels and the trickle down effect will be less housing during a crisis in our nation.
- The barrier to financing will remain if the Small Residential Unit takes over the standard.
- Small manufacturers will be squeezed out of the tiny house on wheels industry, because they will not be able to compete in costs with the large manufacturers that will build the Small Residential Unit.
- The zoning issues for tiny houses on wheels will remain.
I Am REQUESTING A New Revised PINS
I Am Requesting A New PINS Notification To Be Re- Published In ANSI Standards Action To Include Trailer Manufacturers, Modular Manufacturers, Manufactured Home Manufacturers, Transport Carriers, And Owner Builders In The PINS Because The PINS Left Out These Very Important Stakeholders Or Should ICC Relist The Standard In ANSI Standards Action As A Substantitive Change, new PINS Or Both? The Project Needs To Be Addressed As Well.
Project Need
The current PINS failed to give any reason that the Small Residential Unit needed to be added to the standard for the industry need for the tiny house industry and they did not disclose that they were positioning the Small Residential Unit, a made up term no one is using in a primary position over Tiny Houses, a codified term in the IRC, placing Tiny Houses as a subcategory under the Small Residential Unit
May 21, 2025 Addendum To Janet Thome PINS Complaint
Listen To RB42- 25 Code Proposal That Referenced The Standard
The Small Residential Unit Was Vigorously Opposed At The Hearing.
Summary Of Negative Impacts For Tiny Houses
The bottom line is the first meeting of OSMTH 1215 was on January 21, 2024 and early on we heard about the Small Residential Unit, getting rid of Appendix BB Tiny Houses, and immediately it was no longer about tiny houses. I asked for a new PINS since Sept. 2024, and they denied my request. It took until May 16, 2025 for them to submit the revised PINS.
The standard already has a primary focus on the Small Residential Unit, and tiny houses have become a secondary, almost insignificance issue. The standard as is and the direction it is going will not advance tiny houses on wheels.
How You Can Submit Your Own Comments And Pin Complaint To ICC
Please review the previous blog post which is packed with details. It includes my entire PINS complaint, ICC’s new revised PINS adding the Small Residential Unit to the title and scope, 14 months after the standard was developed, and after 20 meetings.
Link Small Residential Unit Hijacking Tiny Houses In OSMTH 1215
Tiny House Alliance USA Editor
May 21, 2025
The Future Of Tiny Is Now!
Janet Thome Founder And President
ja***@******************sa.org
509 345 2013
