A building permit is required to build, demolish or alter any carport, garage or shed that is greater than 200 square feet in area (measured from the interior side of the exterior walls) or greater than 10 feet in height (measured from the finish floor level to the average height of the roof). Depending on the scope of work, your project may also require electrical, plumbing or mechanical permits.
A building permit is not required to construct a non-habitable accessory structure that is 200 square feet or less in area. However, a zoning permit could be required.
Your permit will be reviewed for compliance with the Portland Zoning Code, the Oregon Building Code and other local regulations.
- Applicable City and State Codes: Refer to the Codes page on the Bureau of Development Services (BDS) website.
- Portland’s applicable building code is the Oregon Residential Specialty Code. See the State Codes page for more information about this and other construction codes in effect.
- The Portland Zoning Code (City Title 33) includes use regulations and development standards, such as maximum building coverage and setbacks, and can be found on the Zoning Code page.
Our "New Users" tab is a good place to start for overall information about the permitting process.
Things to Consider when Planning your Project
(1) Location on the Lot
The Zoning Code, (City Title 33) includes regulations and development standards, such as maximum building coverage and setbacks, which will affect the size and placement of the structure on your property.
Visit Planning and Zoning staff at the Development Services Center or call (503) 823-7526 to determine your setbacks.
(2) Fire Walls and Fire Protection
The building code does not restrict placement of a structure on the lot, but it does require that if a structure is close to a property line, it must be constructed to a greater level of fire protection. Construction within three feet of a property line that you share with a neighbor (not a street or public alley) is required to be fire rated. See our handout on Eaves and Exterior Wall Protection.
If your accessory structure is a garage and it will be attached to, or within three feet of the house, then the interior walls of the garage must be covered with a layer of ½" gypsum board for additional fire protection. Any openings (such as doors and windows) within this distance may be required to be protected, depending on the configuration.
(3) Building a Garage
The City requires that a garage be accessed via a driveway. If you don’t currently have a driveway you will be required to put one in. The driveway will need to be paved if it is within 150’ of an improved public right-of-way. For additional information on paving surfaces, see Portland City Code, Title 24.45.020. The Zoning Code also includes requirements that may limit the width of a new driveway.
If your project requires construction in the public right-of-way, then the Portland Department of Transportation will review the project, and issue a separate transportation permit for this work as well. For more information about right-of-way requirements, contact the Portland Department of Transportation at (503) 823-7002.
(4) Cargo Containers
Sometimes, cargo containers can be used as accessory structures. These are challenging in that they too must meet all the requirements of the code.
(5) Residential Engineering
Your project must be designed to meet all structural requirements in the building code. The construction drawings must show how both gravity and lateral (wind and earthquake) loads will be resisted. Please see our page on Residential Engineering for more information on these requirements.
(6) Decommissioning a Septic Tank or Cesspool
When building an accessory structure, the septic tank/cesspool must be located if it exists.
- Visit the records staff at the Development Services Center to locate any old plumbing records showing a septic system/cesspool.
- If the septic system/cesspool is decommissioned, and within ten feet of the new structure, you must sign a disclaimer for on-site-sewage disposal system form.
- If the septic system/cesspool is within ten feet of the new structure, it will need to be decommissioned.
Call Environmental Soils staff at (503) 823-6892 for more information on decommissioning septic tanks and cesspools.
Permit fees are based on the fair market value of the work included in the permit.