Registration: https://www.oregon.gov/ODOT/DMV/docs/vehicle/trassembled.pdf
Construction requirements for tiny houses that will be sold or rented:
The provisions of OAR chapter 918, division 525 apply to the design, manufacture, conversion, alteration, and repair of recreational vehicles and recreational park trailers rented, leased, sold, installed, or offered for rent, lease, or sale in Oregon.
Adopted Minimum Safety Standards
Effective October 1, 2011 the following standards are adopted by reference as the standards for the manufacture, conversion, alteration, or repair of recreational vehicles, recreational park trailers, accessory buildings, and accessory structures:
(1) The 2011 Edition of NFPA 1192, Standard on Recreational Vehicles, as published by the National Fire Protection Association, and further amended by the Division.
(2) The 2009 Edition of ANSI 119.5, Standard for Recreational Park Trailers, as published by the American National Standards Institute, and further amended by the Division.
(3) The 2011 Edition of NFPA 70, National Electrical Code, specifically but not limited to, Article 551 pertaining to Recreational Vehicles and Article 552 Park Trailers, as published by the National Fire Protection Association, and further amended by the Division.
(4) The 2011 Edition of ANSI/RVIA Standard for Low Voltage Systems in Conversion and Recreational Vehicles, as published by the Recreational Vehicle Industry Association.
(5) The Oregon Residential Specialty Code, as adopted in OAR chapter 918, division 480, and those standards referenced within are adopted as the Division’s standards for the construction, manufacture, alteration, repair, and conversion of accessory buildings and accessory structures used in conjunction with recreational vehicles and recreational park trailers.
Source: http://arcweb.sos.state.or.us/pages/rules/oars_900/oar_918/918_525.html