The City of Portland welcomes the opportunity to work with you on your retaining wall project. Learn more about permit requirements for a new retaining wall. You can also schedule an appointment to discuss your project.
When you need a permit for a retaining wall
A building permit is required when constructing a retaining wall that:
- is more than four (4) feet high, measured from the bottom of the footing to the top of the wall.
- supports a surcharge. A surcharge is an additional load, beyond the normal weight of a level earth backfill is to holding back.
If a building permit is not needed, you may need a zoning permit - contact the Zoning Information Line phone number with questions. For complex sites or if slope stabilization is needed, you may need a Site Development permit - contact the General Inquiries phone number with questions.
Who can do the work
Contractors must have a license to work in Oregon. The Oregon Construction Contractors Board (CCB) issues licenses to contractors. The permit application and their company materials must list the license number. Need help finding a contractor? The CCB website has good tips on how to search for one. Plumbing and electrical contractors have additional license requirements.
If you are a homeowner doing the work yourself, please note what is required for a completed application. The State of Oregon has some helpful information for homeowners:
Building permit application and important forms and information
The following information is part of the application. This is everything you might need when applying for a retaining wall permit. Since every project is unique, there may be some situations where you will be asked to provide additional information. Things you need to apply for this permit may include some or all of the following. Read more about site plans and what to include in your application.
If you aren't sure what forms you need, contact Permitting Services. You might want to read our step-by-step guide for completing a building permit application. Permit forms include:
Building permit application
Additional forms for a retaining wall permit application
Step 1: Research what you need for a residential retaining wall
How to check the permit history for a house
Depending on the age of your house, we may have information about the permit history. It is important to verify the permit records, and not rely on the tax information from the county assessor’s office.
If you want to review the permit history, some records are available online. Visit the How to Request Public Property Records webpage.
Codes and Rules
Residential retaining walls that require building permits are regulated by the following codes:
- Oregon Residential Specialty Code
- Title 33 Zoning Code
Other codes may apply based on the scope of work. The City and State Codes, Administrative Rules, Code Guides and Program Guides web page has the codes, administrative rules, code guides and program guides.
Permit fees are based on the type of permit, the work proposed, the valuation of the work, and the staff that need to review the work. Get permit fee information.
Step 2: What you need to get a residential retaining wall permit
In addition to the building permit application, you will need a site plan (often called a plot plan) and engineering information to get your permit. An engineer registered in the State of Oregon must provide stamped drawings and calculations for wall(s) over four feet tall.
Since every project is unique, there may be some situations where you will be asked to provide additional information.
Site plan (Scale site plans to most appropriate scale, e.g. 1”=10’ or 1/4”=1’)
- Property lines, with dimensions
- Adjacent streets and any easements
- Property address and R number
- North arrow
- Distance between buildings and between buildings and property lines
- Dimensions and area (in square feet) of any proposed paving. (If your project will add more than 500 square feet of impervious area you will need to provide a mitigation form and/or a stormwater plan)
- Dimensions and placement of the new retaining wall on the lot
Structural Engineer stamped drawings and calculations
Design of retaining walls over four feet tall should include a site sketch consistent with the site plan submitted with the application.
Or, instead of a site sketch in the calculation package, the engineer may submit a letter stating that the calculations were prepared for the site as shown on the submitted site plan prepared by others.
Where the retaining wall influences the loads on a building, the engineering evaluation should address the effect of the loads imposed onto the building. In all cases, and especially where tiered retaining walls are proposed, the analysis shall include complete free-body diagrams of the retaining walls showing all loads acting on the retaining wall system and all loads used to resist the applied forces. The calculations shall clearly state all assumptions and list the soil design parameters used in the design.
Some sites may require a geotechnical report.
Site development review
Depending upon the placement of the building or structure, the following items must be addressed in evaluation and analysis of the design:
- Slope and retaining wall drainage
- Erosion control
- Potential for shallow failures
- Potential soil creep
- Potential settlement
- Effect of surcharge loads such as new building and/or structure footings
- Protection of adjacent property and existing building during construction
For more information contact General Inquiries.
If your project requires construction in the public right-of-way, 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 Transportation at (503) 823-7002.
Make sure that the design of your retaining wall does not result in a section of the foundation or specifically the “toe” (the outside points of each leg of a structural angle) needing to be placed off of your property.
Soils and/or structural special inspections
Soils special inspections and/or structural special inspections may be required prior or during the construction of your retaining wall.
Soils special inspections may be required for work that includes foundation work of a more complicated nature such as piling, or foundations on steep slopes or large jobs; and retaining walls, landslide slope remediation work or other earthwork-related work. Soils special inspection is performed by the geotechnical engineer of record and/or an approved testing agency and is hired for this purpose by the (permit holder) property owner. Read more about special inspections.
Step 2b: Still need help? Schedule a 15-minute appointment
This is an optional step. If you still need help, we are here for you if you have questions about the information and materials you need to apply. You can schedule a free 15-minute appointment with any of these reviewers:
- Meet with a City Planner to receive information about planning and Zoning and Tree Code requirements that apply to your property.
- Meet with a Building Code and Engineering Reviewer to get help with building code and engineering requirements.
- Meet with a Permit Technician if you have questions about the permit process or if you need help with application requirements.
If you need help, these are experts we recommend you meet with for this project. Not all review groups are listed. The groups listed above will help get you started.
Step 3: Apply for a residential retaining wall building permit
To apply for a permit, submit the completed building permit application and site, architectural and structural plans (for the area of proposed work and areas affected by such work) and engineering calculations.
Get step-by-step instructions submitting a permit application request online.
If you need to submit paper plans, you can set up an appointment to pick up plans or drop off plans in person. Or, please call us and we will work with you.
Step 4: Plan review process and checksheets
You can check the status of a permit review on Portland Maps permit/case search. Many people might review a single permit. The Permit Review Process webpage has more information about the groups who review permits and the steps for getting a permit.
A checksheet is sent to the applicant when a reviewer needs additional information or a correction has to be made to the plans. Read more about how to send us corrections and how to prepare corrected paper plans.
Step 5: Get your retaining wall permit and check your permit status
When the last technical review is approved, your permit will be pre-issued. Pre-issuance is the last permit check. This step ensures all required reviews took place, all required approval stamps are on the plans, and the fees are charged correctly.
You will be contacted when your permit is ready, and notified of your final fee total. Instructions will be given on how to get your approved permit and pay your fees. Your permit is not issued until all fees are paid.
Find out if a permit application is still under review, in process or about to be issued.
Step 6: Start building and get ready for inspection
The inspection card lists all the inspections you will likely need during your construction project, and what work needs to be done first.
Once your building permit is issued, erosion control measures and sometimes tree protection measures must be installed, inspected and approved prior to beginning any further ground-disturbing activities.
All permits need a final approval inspection to be complete.
Step 7: Schedule an inspection, get inspection results and make corrections
To schedule an inspection, call the Requests for Inspections phone number. You will need your IVR or permit number and the three-digit code for the inspection.
Get the results of the inspection on Portland Maps permit/case search the next day. Read more about why work does not get approved and how to schedule a reinspection.
Contact residential inspectors about your permit inspections
If you have questions before or after your inspection, you can talk to an inspector.