Retaining Walls: Auburn vs Kent
How do retaining walls rules compare between Auburn, WA and Kent, WA?
Auburn and Kent have similar restriction levels.
Auburn, WA
King County
Retaining walls over 4 feet from footing to top require a building permit and engineering in Auburn under IRC R105.2. Walls near Lea Hill and Lakeland steep slopes face critical area review.
View full Auburn rules →Kent, WA
King County
Kent requires a building permit for retaining walls over 4 feet tall measured from footing to top. Walls supporting surcharges or on geologically hazardous slopes need a permit at any height under WAC 51-16.
View full Kent rules →Key Facts Comparison
| Fact | Auburn | Kent |
|---|---|---|
| Permit Trigger | Over 4 feet | - |
| Engineering | Required over 4 ft | - |
| Critical Areas | Lea Hill, Lakeland steep slopes | Always permit needed |
| Code | IRC R105.2 / ACC 16.10 | WAC 51-16-080 / KCC 11.06 |
| No Permit | - | Under 4 feet unsurcharged |
| Permit Needed | - | Over 4 feet or surcharge |
Highlighted rows indicate differences between cities.
Auburn FAQ
Do I need a permit for a 3 foot retaining wall in Auburn?
Generally no, unless it supports a surcharge or sits in a critical area. Walls 4 feet or less that do not support fill above are permit-exempt under IRC R105.2.
Is engineering required for retaining walls in Auburn?
Yes, for any wall over 4 feet and for walls in steep-slope critical areas, engineered design stamped by a licensed Washington engineer is required.
Kent FAQ
Do I need a permit for a retaining wall in Kent?
Only if the wall exceeds 4 feet from footing to top, supports a surcharge, or sits in a critical area under KCC 11.06.
Is a rockery considered a retaining wall in Kent?
Yes. Kent treats dry-stack rockeries under the same 4-foot height threshold as engineered retaining walls.
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