Petaluma, CA Accessory Structures: Tiny Homes (2026)
Tiny home rules in Petaluma, CA, covering tiny houses on wheels (THOWs), park model RVs, and tiny home on foundation builds, determine where they are legal and how they get permitted.
Key Facts
- Governing provision
- PMC § 17.04.010(C)
- Adopted standard
- 2025 CRC Appendix BB, Tiny Houses, in full
- Local additions
- None found beyond fee-schedule substitution
- Permit required
- Yes, standard Chapter 17.04 building permit
- Moveable tiny houses
- Generally treated as RVs, not this code path
Summary
Petaluma regulates tiny houses through the state building code it adopts by reference rather than a standalone city ordinance. Municipal Code § 17.04.010(C) adopts the California Residential Code's Appendix BB, Tiny Houses, in its entirety, so a tiny house built on a foundation in Petaluma must meet those state standards and go through the city's normal building-permit process.
Pursuant to Section 50022.2 of the California Government Code, the following codes are adopted by reference, including the amendments listed in this chapter which are made pursuant to the findings of fact set forth in the ordinance codified in this section: ... Part 2.5—2025 California Residential Code based on the 2024 International Residential Code including Appendix BG (Sound Transmission), Appendix BH (Automatic Vehicular Gates), Appendix BB (Tiny Houses), Appendix BI (Light Straw-Clay Construction), Appendix CI (Swimming Pool Safety Act), and Appendix CH (Emergency Housing) in their entirety except as amended in Section 17.04.020;
Official source re-checked September 8, 2026: no newer edition of the code had been published (publisher’s edition: current through Ordinance 2931 NCS, passed July 6, 2026).
Full Breakdown
" That single adoption sentence is what makes Appendix BB, the state's tiny-house construction chapter covering minimum ceiling heights, loft egress, and reduced fixture and space requirements for dwellings under 400 square feet, operative law inside the city. 04, and the permit fees are set by the Petaluma City Council's own fee resolution rather than by the state code's fee tables. There is no separate Petaluma tiny-house ordinance beyond this adoption; the city has not layered additional local size, siting or occupancy restrictions onto Appendix BB in the file provided.
A movable tiny house on a chassis is a different matter and is typically treated as a recreational vehicle rather than a permanent structure, which is outside the scope of this building-code adoption. Anyone planning a foundation-built tiny house or a tiny-house accessory dwelling unit should confirm with the Petaluma building division which code path (Appendix BB versus standard ADU review) applies to their specific project.
Violations & Fines
Constructing a tiny house without the required building permit falls under Chapter 17.04's general enforcement: the building official may issue a stop-work order carrying an investigation fee of one to five times the normal permit fee, and unpermitted construction is a misdemeanor punishable by up to a $1,000 fine and/or six months in jail, with each day of continued work a separate offense.
Frequently Asked Questions
Does Petaluma have its own tiny house ordinance?
Do I need a permit to build a tiny house in Petaluma?
Are tiny houses on wheels covered by this rule?
Sources & Official References
Other rules in Petaluma
California rules heatmap·Compare Petaluma to another location·View the California accessory structures overview
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How other cities in Sonoma County handle tiny homes.