Multnomah County, OR Fence Regulations: Retaining Walls (2026)

The county's zoning code lets a fence or retaining wall sit inside a required yard despite the base zone's minimum yard dimensions, but only up to six feet in height at the lot line. Once a fence or retaining wall exceeds six feet, it must be pulled back from all lot lines by a distance at least equal to its own height -- an 8-foot wall needs an 8-foot setback, for example. The standard is written into the dimensional-requirements section of each rural base zone (EFU, MUA-20, RR and others) and applies only to unincorporated county land; Portland, Gresham, Troutdale, Fairview and Wood Village enforce their own city codes instead.