Oregon Revised Statutes Public Health and Safety § 446.245

(a) Manufactured dwellings may be used for purposes other than as a single-family dwelling when specifically approved for a change in occupancy in accordance with the provisions of the Oregon specialty codes by the authority having jurisdiction. When a manufactured dwelling changes in occupancy it shall lose its identity as a manufactured dwelling and have the insignia removed and returned to the Department of Consumer and Business Services.

(b) Manufactured dwellings may be used by dealers or distributors of manufactured structures as temporary sales offices when no alterations to the design, construction, transportation, fire and life safety, plumbing, mechanical or electrical systems are made to accommodate the office use and when the dealer or distributor continues to offer the manufactured dwelling for sale during the office use.

(c) A portion of a manufactured dwelling may be used for an in-house business when the remainder of the structure is used as a single-family dwelling by the same person. The type and location of an in-home business shall be approved by the authority having jurisdiction and the local planning commission prior to the use.