What Is A Small Residential Unit ( SRU) ?
A Small Residential Unit ( SRU) is defined as -A dwelling unit that is 1,200 square feet or less constructed as a permanent residential structure with or without a permanent chassis system in the new tiny house standard currently being drafted by the International Code Council. The committee is trying to position the Small Residential Unit ( SRU), A made up term that is not currently enforced by building officials, or recognized by anyone in a primary position over Tiny Houses, a codified IRC term, placing Tiny Houses as a subcategory under the SRU.
ICC And THIA Are Co-Branding A Tiny House Standard
ICC and the Tiny Home Industry Association ( THIA) are co-branding a standard together titled-The ICC/THIA Standard 1215, Design, Construction, Inspection and Regulation of Tiny Houses for Permanent Occupancy.
The goal is to submit the standard to the inclusion of the 2027 IRC as a code proposal, which has currently been submitted. The agenda number is RB42-25.
The code proposal will be heard at the first ICC CAH # 1 committee in Orlando, Florida on April 28, 2025. The hearings are open to the public and there will be a virtual streaming option.
Register For The Hearings
The original purpose of the standard was to fill in the gap of what the tiny house industry lacks. The primary goal was to add provisions for tiny houses on wheels. Appendix Q Tiny Houses that was approved for the inclusion of the 2018 IRC only applied to tiny houses on a foundation, and the provisions for movable structures were not allowed, and in fact, were considered a hijack of the proposal by ICC, so the provisions were removed.
ICC and THIA jointly disrupted the final approval of an ASTM Tiny House committee for ONE YEAR with false claims of duplication after we had the support of Colorado and New Hampshire legislators and now are duplicating ASTM, causing confusion in the marketplace and pitting the industry into sides. Sides should not be in the equation, the common goal is to create a standard for tiny houses on wheels to be recognized and approved as housing.
The Standard Has Been Hijacked By The SRU
The ICC/THIA standard is no longer a tiny house standard, it has been hijacked in a new direction toward a new made up term called a Small Residential Unit ( SRU ), a new housing type no one is currently recognizing or heard of.
What is an SRU? Exactly. This is a term that is not recognized by building officials, architects, engineers or anyone and is not enforceable.
The committee is positioning the SRU over the term tiny houses, a codified term in the IRC. Tiny Houses would be a subcategory of the SRU.
Definitions In The ICC/THIA 1215 Standard. What Is An SRU?
SMALL RESIDENTIAL UNIT (SRU). A dwelling unit that is 1,200 square feet or less constructed as a permanent residential structure with or without a PERMANENT CHASSIS system.
TINY HOUSES. A SMALL RESIDENTIAL UNIT 400 square feet or less with or without a PERMANENT CHASSIS system.
Who Is Making The Decisions? ICC Stacked The Vote
ICC is an ANSI Standard Developer and standards must comply with the ANSI Essential Requirements For Due Process to allow equity and fair play.
The OSMTH 1215 committee consists of 18 voting members, one third are building officials. The other voting members were supposed to be chosen to provide a balance of interests, and the standard development setting was not supposed to be dominated by a single interest category, individual or organization. Dominance means a position or exercise of dominant authority, leadership, or influence by reason of superior leverage, strength, or representation to the exclusion of fair and equitable consideration of other viewpoints.
The committee consists of 7 board members of THIA, and 2 hand picked close associates of THIA. One board member of THIA recently resigned and is also paid staff of ICC.
The direction and end game were decided by ICC and THIA behind closed doors. Qualified candidates were turned down, which would have been a signal to the tiny house industry that the standard was being developed in an open, fair, consensus Process. The committee does not have a balance of interest groups and is dominated by manufacturers, with ZERO representatives of on site manufacturers or owner builders.
The draft of the standard is out of compliance with the title, scope, working group scopes, pins notification that announced the standard in ANSI Standards Action, and introduction of the standard with a primary purpose of tiny houses with provisions for on site and off-site construction.
The Agenda Of The Small Residential Unit- Who Stands To Benefit ?
The Small Residential Unit is the agenda of both ICC and THIA that is documented by the fact that it was a topic of discussion at the Long Beach webinar in October 2024, that was registered for continuous education credits, registered with AIA.
The webinar was titled Approving Small Residential Dwelling Units: ADUs and Tiny Homes.
Could the goal of the SRU be to replace manufactured homes so the inspection, certification, and regulatory compliance is under the umbrella of ICC, benefiting their subsidiaries? The SRU will squeeze out small manufacturers and create a barrier to entry with over regulations for small manufacturers, including 100% plant inspection, emulating HUD requirements for factories for manufacturers that build to the Manufactured Home Construction and Safety Standards (MHCSS), commonly known as the HUD code.
Note: OSMTH 1215 is destined to be a companion standard, bundled with the ICC off-site construction standards that include ICC/MBI 1205 Standard for off-site construction: inspection and regulatory compliance.
With the rising cost of materials, how can a small manufacturer compete with large manufacturers that build in huge factories in assembly lines? They cannot.
Tiny Houses Are Left On The Side Of The Road Again
RB42-25 is currently a code proposal that was submitted by the vice chair of the OSMTH 1215 committee as the main proponent, who is also a board member of THIA.
The code proposal change does not correlate with the definitions of the Small Residential Unit or Tiny House definition in the standard and conflicts with each other.
The proposal omits the chassis in the definition of a Small Residential Unit, and surprisingly does not add the chassis to the Appendix BB Tiny Houses, and the exception does not include the term Small Residential Unit.
Is it because the ICC analyzed the code proposal and determined that adding the chassis to either section would cause it to fail, because a tiny house on wheels is a vehicular unit, a structure integrated on a trailer? A trailer is considered a motor vehicle, and motor vehicles are regulated by NHTSA and DOT, not considered real property, or considered a permanent residence.
The Small Residential Unit is going against the trend to address solutions to the housing crisis to decrease square footage requirements and increase density on lots by allowing multiple smaller homes, including tiny houses, 400 square feet or less.
Are We Right Back Where We Started From 7 Years Ago When ICC Did Not Allow Provisions For Tiny Houses On Wheels?
RB42-25 Code Proposal
Call To Action- What You Can Do
- View The Draft
- Sign Up At ICC To Become An Interested Party And Attend The Calls
- Create An ICC Cp Access Account To View Code Proposals, Leave A Public Comment For RB42-25
- Go To The Hearing In Florida At The End Of April
Appendix Q Tiny Houses
With the inclusion of Appendix Q Tiny Houses into the 2018 IRC, the code has become the initial crowning achievement for the tiny house industry that finally brought the consumers, the building officials, legislators, owner builders and manufacturers together with the beginning stage for uniformity in the tiny house industry.
The 2021 IRC Edition renamed the code, Appendix AQ Tiny Houses.
The 2024 IRC Edition has renamed the code, Appendix BB Tiny Houses, and states and local jurisdictions are currently still adopting the code.
Appendix Q Tiny Houses was co-authored by Andrew Morrison, Martin Hammer , David Eisenbery, Macy Miller, and more contributing authors.
The initial proposal had movable provisions for tiny houses on wheels, though as Andrew Morrison stated;
‘’I had to make some last minute changes to the proposed code language to remove the word “moveable” from my original proposal entitled “Movable Tiny Houses.” Unfortunately, the head of the ICC code approval process said that he would not accept the proposal as written because he believed it was what they call in the industry a “hijack” of the original proposal. After many conversations and emails with the official, I decided to amend the proposal so that he would allow it to move forward. After all, when he said “if you keep the moveable details in there, I will throw the whole thing out” it became crystal clear what my options were.
That said, tiny house Appendix Q does take away the vast majority of the challenges a moveable tiny house would face, leaving the chassis/trailer as the last major potential roadblock (fear not, there’s good news to follow). As such, builders and owner builders alike can submit an application for the foundation design through Section R104.11 of the IRC entitled Alternative materials, design and methods of construction and equipment. This application simply needs to show how the chassis/trailer can be incorporated into a suitable foundation to meet the intent of the code. This design could likely draw heavily on Appendix E: Manufactured Housing Used As Dwellings, as the majority of that appendix focuses on mounting a chassis/trailer to a code approved foundation for manufactured housing. This is a great place to start for using the code itself to support your design and long term plans.’’
OSMTH 1215 Tiny House Standard
What incentive would a jurisdiction have to lower the square footage to allow a tiny house 400 square feet or less, if the SRU becomes the norm? ZERO.
Tiny House Alliance USA Editor
April 15, 2025
The Future Of Tiny Is Now!
Janet Thome Founder And President
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