Building Code Guide 16-10: Temporary Prefabricated Structures

Building Code Guides (BCGs) and Building Official Determinations (BODs) provide answers about the application of building codes and outline optional alternates. BODs are typically smaller in scope and address simpler questions. Code Guides provide a comprehensive alternative to a complicated set of code requirements.

BCG 16-10: Temporary Prefabricated Structures 

QUESTION 1: Can prefabricated structures, as defined in OAR 918-674, used as temporary storage space during an alteration or addition to an existing building or construction of a new building, or for a temporary sales or leasing office, or for other allowed temporary uses, be placed on a construction site?

RESPONSE 1: Portland Permitting & Development (PP&D) will allow prefabricated structures for temporary storage space of a business that is being enlarged or remodeled, or for a temporary sales or leasing office for a project such as condominiums, residential or commercial subdivision or commercial rental space, or for other allowed temporary uses, to be placed on a construction site under the following conditions:

1. Standards
   1. The location and use of the prefabricated structure complies with Chapter 33.296, Temporary Activities, of the Portland Zoning Code. In some cases the temporary use may not be allowed by the Portland Zoning Code, or may only be allowed only as a permanent use. In those cases, use of this code guide is prohibited.  In addition, any associated development such as parking required by item A.7 below, must comply with applicable requirements of the Portland Zoning Code; 
   2. The prefabricated structure is installed according to current PP&D Structural Engineering and Site Development policies as described in BCG 15-10: Prefabricated Structure Foundations; 
   3. The prefabricated structure is occupied only by employees of the business being enlarged or remodeled, or by sales or leasing staff and their customers for the sole purpose of sales or leasing the associated project; 
   4. The prefabricated structure is located on the same site or on an adjacent site that is under the same ownership as the building being built, enlarged or remodeled. Alternately, the prefabricated structure may be located on an adjacent site that is leased for the purposes of construction; 
   5. The prefabricated structure meets building code setbacks from any adjacent structure or property line; 
   6. The egress path from the prefabricated structure to the public way is unobstructed and does not pass through a construction area;
   7. Accessible parking and an accessible route to the prefabricated structure is provided in accordance with State and Federal statutes; 
   8. Access and distance to the minimum required number of toilet facilities is provided per the Oregon Structural Specialty Code (OSSC); and
   9. The prefabricated structure is State certified for the intended use and bears a State certification label.
2. Procedures
   1. The prefabricated structure is associated with a building permit or site development permit for development of a project that is using the temporary structure, or associated with the construction of a project to be sold or leased; 
   2. The location and use of the prefabricated structure is clearly shown on the plans submitted with the associated building permit application;
   3. A separate building permit must be obtained for the prefabricated structure itself, and must note the permit number(s) of the project it is associated with. It must note that the structure is to be removed within 24 months from permit issuance or 30 days after all permits for the associated project are final, whichever occurs first (See B.5, below); 
   4. The plans submitted for building permit for the prefabricated structure include both a copy of the State approved drawings for reference, and drawings of the elements that the local jurisdiction is required to review; and
   5. The building permit for the prefabricated structure is valid for not more than 24 months after it is issued, or not more than 30 days after final inspection approval of all associated building permit(s), whichever occurs first. Requests submitted in writing for one or more extensions not to exceed 180 days each may be considered on a case-by-case basis for unique circumstances. 

QUESTION 2: Can prefabricated structures, as defined in OAR 918-674, used as a temporary job trailer during an alteration or addition to an existing building or construction of a new building, be placed on a construction site?

RESPONSE 2: PP&D will allow prefabricated structures used for a temporary job trailer during an alteration or addition to an existing building or construction of a new building to be placed on a construction site under the following conditions:

1. Standards
   1. The location and use of the prefabricated structure complies with Chapter 33.296, Temporary Activities, of the Portland Zoning Code, including the standards specific for construction staging areas in 33.296.030.F.4. In some cases the temporary use may not be allowed by the Portland Zoning Code, or may only be allowed only as a permanent use. In those cases, use of this code guide is prohibited; 
   2. The prefabricated structure is occupied only by construction employees during the duration of project construction; and
   3. The prefabricated structure is located on the same site or on an adjacent site that is under the same ownership as the associated construction project. Alternately, the prefabricated structure may be located on an adjacent site that is leased for the purposes of construction.
2. Procedures
   1. The prefabricated structure is associated with a building permit or site development permit for development of a project that is using the temporary structure; 
   2. The location and use of the prefabricated structure is clearly shown on the plans submitted with the associated building permit or site development permit application; and
   3. A separate zoning permit is obtained for the temporary job trailer that meets the construction staging areas standards of Chapter 33.296, Temporary Activities, of the Portland Zoning code. The permit must note the permit number(s) of the project it is associated with, and that the structure is to be removed after all permits for the associated project receive final inspection approval. 

HISTORY: Implemented June 13, 2016.

DOWNLOAD a copy of this Code Guide:

QUESTIONS? Free 15-Minute Appointments for Permit, Code, and Zoning Questions