Portland, OR Fence Regulations: Retaining Walls (2026)
Key Facts
- Permit threshold
- Over 4 feet, footing to top
- Surcharge walls
- Permit required regardless of height
- Design standard
- ASCE 7-16 engineering required
- Sliding/overturning safety factor
- Minimum 1.5 (1.1 with seismic)
- Governing code
- Title 24, Chapter 24.70
Summary
Portland requires a permit for any retaining wall over 4 feet tall, measured from the footing bottom to the wall top, and for any wall supporting a surcharge; engineered design is mandatory beyond that height.
Retaining walls. A permit is required and will be issued in accordance with Section 24.10.070 for all retaining walls over 4 feet (1219 mm) in height measured from the bottom of the footing to the top of the wall, and for retaining walls supporting a surcharge.
D. Tree removal. Removal of trees six inches and larger in diameter will be reviewed with the clearing or grading permits as part of the Tree Plan review pursuant to Title 11. When removing 5 or more trees on a site with an average slope of at least 20 percent, applicants must provide a geotechnical engineering report that assesses the stability of the site after tree felling and root grubbing operations.
E. Permits required under this Chapter must be obtained before the commencement of any tree removal, root grubbing or soil disturbance takes place.
Full Breakdown
Portland City Code § 24.70.020(C) requires a building permit for any retaining wall over 4 feet in height, measured from the bottom of the footing to the top of the wall, and for any retaining wall supporting a surcharge: regardless of height. Section 24.70.085 requires walls not covered by the Oregon Residential or Structural Specialty Code to be engineered under ASCE 7-16, addressing soil pressure, seismic loading, and a minimum 1.5 safety factor against sliding and overturning. Walls at or under 4 feet with no surcharge and no steep ascending slope behind them are exempt from the permit requirement.
Violations & Fines
Building without the required permit or engineering review triggers a stop-work order and enforcement action by the City Administrator; unpermitted walls face removal or retrofit orders to bring them up to ASCE 7-16 standards.
Frequently Asked Questions
Do I need a permit for a 3-foot retaining wall in Portland?
Who has to design a Portland retaining wall over 4 feet?
Sources & Official References
Other rules in Portland
Compare Portland to another location·View the Oregon fence regulations overview
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Retaining Walls in Nearby Cities
How other cities in Multnomah County handle retaining walls.