Tiny homes are all the rage these days! You can’t turn on cable TV without coming across at least one or two shows about them, and there are numerous blog articles, websites, and even conventions about tiny homes. If they are so popular, then why don’t we see more tiny homes in our communities?
The simple answer is that our zoning and building/construction regulations create significant barriers against them, especially if someone wants to live in a tiny home on a permanent basis.
A major issue is that most of the zoning provisions discussed above, however, pertain to a tiny home being treated as a permanent dwelling unit. And, therein, lies the dilemma.
Tiny Homes as Temporary Housing vs. Permanent Dwelling Units
In Washington State, a tiny home with wheels and a chassis is actually called a park model recreational vehicle (PMRV) and is approved only for temporary/recreational use in the state. A tiny home/PMRV with its wheels taken off and mounted on a foundation will still be viewed as a park model recreational vehicle and its use will still be considered as “temporary/recreational” (and not approved as a permanent dwelling unit). Exceptions in state law (RCW 35.21.684 and RCW 36.01.225), however, allow a PMRV to be used as a residence if it is located in a mobile home park, hooked up to utilities, and meets the other requirements of the applicable RCW.
While some tiny home owners intend to use them only for temporary living purposes, others want to use them as permanent, or long-term, residences. In most cases, however, a tiny home/PMRV cannot be converted into a dwelling unit. The International Residential Code (IRC) addresses dwelling units and requires that “permanent provisions for living, sleeping, eating, cooking and sanitation” be provided in a dwelling, along with other requirements such as heating, mechanical and energy efficiency provisions. For example, park model recreation vehicles are only required to meet minimal insulation requirements of R-5 for floor, R-5 for walls and R-7 for ceilings. In contrast, dwellings are held to a much more efficient requirement of R-30 for floors, R-21 for walls and R-49 for ceiling, providing greater energy sustainability.
It is a long and involved process for a tiny home to be approved as a dwelling unit:
- A person would need to submit engineered plans to the Factory Assembled Structure Program of the Washington State Department of Labor and Industries (L&I) for the construction of a “modular building” (or to the local building department for a site-built tiny house).
- Those plans would be reviewed under the specific Washington State Administrative Code (WAC 296-150F) for conformance with the requirements of the IRC.
- Once approved, the builder would request inspections during the construction process until final approval had been obtained…