The Recreational Vehicle Industry Association provides standards for construction of recreational vehicles, including park model RVs. Although in late 2014, the association had temporarily halted adding any new members who built tiny houses, the RVIA is again accepting tiny house builders who manufacturer structures intended for temporary dwelling.
As of March 2015, the cost of joining was a $500 initiation fee plus $2,040 for annual dues plus $600 for 10 seals (RVIA stickers for your tiny houses, must be purchased in lots of 10).
You must submit your designs to the RVIA for review and you must undergo periodic inspections.
For more information about joining, please go to the RVIA website.
From Thom Stanton’s Timber Trails blog,
“Earlier this year, the RVIA’s Matt Wald explained to me [Thom] that the association is no longer allowing tiny house companies to join their ranks of manufacturer members. Here too, and for the sake of their seal’s integrity, their reasoning here remains sound: Most THOW companies don’t produce enough models for their certification inspectors to see all aspects of production during their periodic site inspections.”