Auburn, WA Landscaping Rules: Tree Trimming (2026)

Auburn City Code Chapter 18.50 and 18.76 establish tree preservation and landscaping standards. Routine pruning and maintenance of trees on private property generally does not require a permit if it does not remove the tree. However, significant trees defined under ACC 18.76 as 6 inches or greater in diameter at breast height (DBH) for most species, or 10 inches DBH for certain conifers, should be pruned per ANSI A300 standards and not topped (heading cuts that remove more than 25 percent of the crown are discouraged and may reclassify the work as removal requiring a permit). Property owners are responsible for trimming branches overhanging public rights-of-way so they clear streets by at least 14 feet and sidewalks by at least 8 feet under ACC 12.56. Failure to maintain right-of-way clearance after notice allows the city to perform trimming at owner expense. Dangerous or hazard trees (dead, diseased, or leaning) may be pruned or removed with a hazard tree determination letter from a certified arborist. Critical area setbacks (wetland, stream, steep slope buffers) under ACC 16.10 impose stricter limits; pruning within buffers may require a critical area permit. Boundary trees shared with neighbors may only be trimmed back to the property line by the neighbor without consent, but cannot be topped or killed.