RB42-25-1
There is a saying at ICC that states a code always trumps a standard. A perfect example is a new tiny house code change that is going to be presented at the second CAH Hearing in Ohio that could finally put the wheels under tiny houses and is a much better solution to what the tiny house industry needs as opposed to the ICC 1215 standard. RB42-25-1 is an an I-Code change to Appendix BB Tiny Houses that could be approved for the 2027 IRC. It has been submitted as a public comment to RB42-25 that was submitted at the first CAH Hearing.
The proponents of RB42-25 asked for disapproval at the first CAH Hearing because the standard was in draft form. The ICC 1215 standard was referenced in RB42-25.
Why Does RB42-25-1 Trump ICC 1215?
RB42-25-1 was born out of response to the ICC 1215 standard that is currently being developed and has changed in the wrong direction with the takeover of the Small Residential Unit, placing tiny houses as a subcategory under the Small Residential Unit. ( SRU).
The First ICC CAH Hearing Had Opposition To The SRU
There has been a lot of opposition to the Small Residential Unit, including two petitions that gathered almost 700 signatures and the ICC 1215 standard had huge opposition because of the SRU at the first ICC CAH Hearing. ICC 1215 will not be developed in time for 2027 IRC.
What Is An SRU As Defined In ICC 1215?
SMALL RESIDENTIAL UNIT (SRU). A dwelling that is 1200 square feet (111 m2) or less excluding lofts and is constructed as a permanent residential structure with or without a permanent chassis.
Committee Reason RB42-25
RB42-25
RB42-25-1 Public Comment To RB42-25
Listen Live To Hear Code Proposal RB42-25-1 October 22, 2025
Estimated Time- 11:30 EST –
What The Approval Of RB42-25 Could Mean?
Nine years ago, movable provisions were not allowed in the tiny house code that resulted in Appendix Q Tiny Houses that was approved for inclusion to the 2018 IRC. The movable provisions were considered a ‘hijack’ of the code proposal.
The tiny house code has been the crowning achievement for the tiny house industry.
The tiny houses code was the first step in creating uniformity for building officials, manufacturers, architects, engineers, designers and more for more placement, but the wheels have presented a problem because wheeled structures are regulated by NHTSA and DOT.
What is exciting is the original authors that drafted Appendix Q Tiny House have united again and donated their generous time and contributed to RB42-25-1 and added the chassis provisions.
The Back Story Of Appendix Q Tiny Houses
The inclusion of a new appendix in the 2018 International Residential Code (IRC) addressing standards for dwellings that are 400 square feet in area or less—commonly called “tiny houses”—represents an important milestone not just for advocates of simpler living, but also for the International Code Council.
Appendix Q Tiny Houses is the first set of building standards for dwellings ever incorporated into a model code. The story of how the appendix came to be is a great example of how the Code Council works together with stakeholders and industry professionals to develop model code standards for new and innovative technologies as they emerge.
Full Article
How Can You Help?
You can be a part of history being made, sign your name to this updated petition when Appendix Q Tiny Houses was being developed in support of RB42-25-1 and let’s wheel the industry forward.
September 20, 2025
