Tiny Houses on Wheels

The first Tiny House on Wheels in Port Townsend, permitted for occupancy

Background

Since July 1, 2023, per Ordinance 3306, Tiny Houses on Wheels (THOWs) are permitted as Accessory Dwelling Units (ADUs), subject to the requirements of Port Townsend Municipal Code 17.58.030. An ADU is a dwelling unit that is accessory to an existing primary residence. As ADUs, up to 2 THOWs may be placed on a lot with an existing single-family residence.

For information on how to establish a THOW as an ADU, please see the THOW ADU FAQ linked at the bottom of this page.
For information on how to establish a Tiny House on Wheels Community with up to 12 THOWs, please see our THOW Community handout.

What is a Tiny House on Wheels (THOW)?

Depending on who you talk to, THOW can refer to a variety of structures, so it is important to know what types of structures are permitted as THOWs in Port Townsend. Per PTMC 17.58, a THOW is defined as a structure no larger than 400 square feet, excluding loft space, that meets the following conditions:

• Is licensed and registered with the Department of Motor Vehicles;

• Is constructed and certified to building and inspections standards in PTMC 17.58.030;

• Is no larger than allowed for movement on public highways;

• Has at least 150 square feet of first floor living space and does not exceed 16 feet in height;

• Is a detached self-contained unit which includes areas for cooking, sleeping, and sanitation.

A THOW is technically a Park Model Recreational Vehicle, which is a factory-built structure or dwelling constructed to American National Standards Institute (ANSI) standards (not State Building Codes) and is certified through the Washington Department of Labor and Industries (L&I). More information is available in the Tiny House on Wheels information handouts and additional resources below.