Help Get Tiny Houses on Wheels Into Building Codes!

I wanted to let everyone at Permies know about the latest effort to finally get tiny houses on wheels codified in the International Residential Code (IRC) at the upcoming ICC code hearing in Hartford, CT in April.

Ever since the tiny house movement started picking up steam, tiny homes have existed in a confusing legal grey area. Manufactured/mobile homes are regulated through the HUD code for full-time living, while recreational vehicles have their own standards as temporary living quarters. Tiny homes, however, fall somewhere between. They are smaller than manufactured/mobile homes, but unlike an RV, they are built for full-time living. They are also often owner built or built by small artisan builders who can’t afford the HUD pathway.

This is why back in 2016 a group of tiny home advocates, including Andrew Morrison and Macy Miller (two of my inspirations when I was designing my own home around this time), participated in a successful effort to create Appendix Q of the International Residential Code (IRC). This created a realistic pathway for homes under 400 square feet to be built. Most jurisdictions in the US use the IRC, so this allowed jurisdictions everywhere to easily adopt this new code.

At the time it was written, the advocates had intended to include provisions for the trailer chassis in the appendix. Unfortunately, this was determined to be too much of a lift and the chassis language had to be scrapped in order to ensure that the appendix could be approved. This meant that Appendix Q really only applied to tiny homes on a traditional foundation.

The intention was always that the chassis (tiny homes on wheels) option could be revisited in a later revision of the appendix. Well, that time is NOW!

Macy Miller has reunited a group of advocates, including Martin Hammer and David Eisenberg, who were both instrumental in making the original tiny house appendix a reality (and have advocated very effectively for a variety of other alternative building techniques) to back a code change comment (RB42-25-1) that would add chassis provisions to the tiny house appendix (now called Appendix BB). There is a real possibility that this proposal could pass. If it does, it will finally give jurisdictions the tools they need to start zoning for movable tiny houses.


TL;DR: Right now we're looking for people who would be willing to send a simple email to their local building official to let them know you support tiny houses (we will provide verbiage when the time comes). The more we can get on board, the more likely this will pass. You can sign up for that here.

You can also sign your name to the petition that will be presented at the hearing: Change.org Petition (Don’t donate here–just sign the petition)

Finally, if able and so inclined, you can donate to help with travel expenses and engineering costs: https://www.gofundme.com/f/support-tiny-homes-in-building-code

Lots more about this effort (including an awesome FAQ) can be found on Macy Miller's 
website: https://minimotives.com/2026/01/18/tiny-houses-the-irc-a-path-to-clear-safe-housing-options

I signed it!

I thought the main impediment to tiny homes was ordinances and local regulations and stuff, restricting the minimum size of a house or its foundation style or whatever (basically a roundabout way to keep "certain" people out of neighborhoods). I had no idea there were code issues. (As far as I know, there isn't any analogous restriction in the NEC.)

Thanks! It is both. Institute for Justice and others have had success at challenging the constitutionality of minimum square footage laws and I believe a lot of those local zoning regulations are changing (they are in my town). Some states like Colorado and Maine recognize tiny houses on wheels and have their own regulations but others just don't know how to categorize them. So this would make it a lot easier for them to recognize and permit them and make the definitions more universal. The local jurisdiction still always has the final authority.

What state are trying to code tiny homes on wheels?

I thought that because they are on wheels codes do not apply to them.  Am I wrong?

If tiny homes on wheels become Code Enforcement then is the RV Industry going to be included?

I just signed!   Great work to all of you who are advocating for international standards!

In the county where I am (western Washington/Olympic Peninsula), there is statutory allowance for tiny homes.... with one incredibly challenging non-negotiable. Any tiny home that is placed on a property for long term use is required to be attached to an inground septic system.  No composting toilets allowed. No sewage tank (like an RV) with a pumping contract. No flexibility. Doesn't matter whether it is on wheels or not.

Hoping your international standards are inclusive of plumbing / sewage topics that can pave the way for more negotiations with the county...

Good luck with it!