Tacoma, WA Accessory Structures: Tiny Homes (2026)
Tiny home rules in Tacoma, WA, 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
- Standard minimum
- two 12x36-ft sections
- Tiny homes
- exempted from that minimum
- Still required
- permanent HUD-standard foundation
- Standard source
- IRC Appendix Q via State Building Code
Summary
Tacoma normally requires manufactured homes built as two sections at least 12 by 36 feet each, but structures meeting IRC Appendix Q tiny-home standards skip that minimum-size rule.
All manufactured homes shall be comprised of at least two fully-enclosed parallel sections, each of not less than 12 feet wide by 36 feet long unless the structure complies with the requirements of IRC Appendix Q – Tiny Homes, as amended by the State Building Code.
D. Manufactured homes shall be set upon a permanent foundation, as defined by the Housing and Urban Development (“HUD”) handbook “Permanent Foundation Guide for Manufactured Housing,” which is sufficient to resist wind and seismic lateral forces, as well as the gravity loads as specified in the IRC, as adopted and amended in TMC Chapter 2.02. The Building Official shall be responsible for issuing all permits for foundations for manufactured homes. “Permanent Foundation” for manufactured homes is defined in the HUD handbook, “Permanent Foundation Guide for Manufactured Housing,” as: Definition of Permanent Foundation. Permanent foundations must be constructed of durable materials; i.e., concrete, mortared masonry, or treated wood – and be site-built. It shall have attachment points to anchor and stabilize the manufactured home to transfer all loads, herein defined, to the underlying soil or rock. The permanent foundations shall be structurally designed for the following:
1. Vertical stability.
a. Rated anchorage capacity to prevent uplift and overturning due to wind or seismic forces, whichever controls. Screw-in anchors are not considered a permanent anchorage.
b.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: rev 4946110; v22 updated 2026-07-28).
Full Breakdown
TMC § 2.02.620.C sets the baseline manufactured-home standard: at least two fully enclosed parallel sections, each a minimum of 12 feet wide by 36 feet long, before the home can be installed in the City. The same subsection carves out an exception for tiny homes, a structure meeting IRC Appendix Q, as amended by the State Building Code, doesn't have to meet that two-section minimum-size rule. A qualifying tiny home must still meet the rest of § 2.02.620's conditions, including a permanent HUD-standard foundation and State Energy Code compliance.
Violations & Fines
A manufactured or tiny home meeting neither the standard two-section size minimum nor the IRC Appendix Q exception is a Building Code violation subject to permit denial by the Building Official.
Frequently Asked Questions
Can I put a tiny home on a lot in Tacoma?
Does a tiny home still need a permanent foundation in Tacoma?
Sources & Official References
Other rules in Tacoma
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