ICC 1215 Is An Obstacle To HUD And Motor Vehicle Preemption
For several years, I have raised federal preemption concerns regarding ICC/THIA 1215, Standard for Design, Construction, Regulation and Enforcement of Tiny Houses for Permanent Occupancy. My letters address two separate but related issues: HUD manufactured-housing preemption and federal motor-vehicle transportation law.
The first concern involves statements in the standard’s Foreword and ICC’s model legislation suggesting that a manufacturer may “opt out” of HUD requirements or that local adoption of ICC/THIA 1215 may allow a structure to qualify for an exemption. Federal law already provides a pathway for qualifying modular homes under 24 C.F.R. § 3282.12. That exclusion exists now and does not depend upon adoption of ICC/THIA 1215. A voluntary standard cannot create, expand, or replace a federal exclusion, and, manufacturers relying upon inaccurate guidance could face serious enforcement consequences.
The second concern involves Chapter 7, Transportation. ICC/THIA 1215 regulates highway movement, transportation loading, chassis systems, in-transit structural conditions, and documentation of unspecified “DOT requirements,” while excluding an “independent carrier system” from the chapter. My position is that the transportation section in its entirety conflicts with the federal transportation framework. Silence or newly created terminology cannot remove a regulated trailer from federal law.
NHTSA has already addressed modular-home transportation directly. Its interpretation states that the modular home is not a motor vehicle, but the trailer used to transport it is a motor vehicle that must comply with applicable federal standards and certification requirements.
ICC rejected my preemption claims and asked that I refrain from submitting further claims based upon motor-vehicle laws. I respectfully disagree. I am publishing my letters and ICC’s response so the public, manufacturers, regulators, transporters, and code officials can examine the complete record and reach their own informed conclusions about whether ICC/THIA 1215 conflicts with federal law.
Legal Principles: Obstacle Preemption
- Supremacy Clause: Under the U.S. Constitution, federal law is the highest law. State or local rules that interfere with federal goals are invalid.
- Implied Conflict: An obstacle exists if a state rule stops the full execution of the goals of Congress, even if the federal law does not explicitly ban the specific state rule.
- Uniformity: The primary purpose of preemption in this sector is to ensure that federal safety programs work identically in every state, preventing states from using local building codes to bypass federal authority.
NHTSA Interpretation Letter
My Preemption Inquiry
My Preemption Inquiry To ICC
My Preemption Inquiry
ICC Email Response: June 1, 2026
Dear Ms. Thome,
We have received your letter regarding the PINS update request and committee makeup and appreciate your engagement in the process
Committee composition is established in accordance with approved procedures to ensure a balanced representation of interests. The current committee reflects a diverse range of skills and expertise necessary to evaluate the subject matter effectively. In addition, input from approximately 30 interested parties further enhances the breadth of perspectives considered. The ICC standards consensus process is open and transparent, and participation is available to any individual or organization with an interest in the topic.
We encourage you to continue addressing your concerns through the subject committee. If you believe your concerns have not been adequately addressed, and that there has been a non-conformity with the consensus procedures, you may submit a complaint or appeal via the ICC Codes and Standards Portal.
Best Regards,
Karl W. Aittaniemi, P.E.
Director of Standards
Codes and Standards Development
ICC Response To Janet Thome
My Response To ICC
My Lastest Response To ICC
Current Draft
August 1, 2026
