Walla Walla County, WA Building Setbacks & Zoning: Lot Coverage Limits (2026)

Walla Walla County regulates building coverage through the table of density and dimensional requirements at WWCC § 17.18.020 rather than a single flat percentage. The table's Maximum Coverage column applies zone by zone: Single Family Residential R-72 and R-60 lots are limited to forty percent lot coverage, expandable to forty-five percent under development condition 11 when the structure includes a two-family dwelling unit. Suburban Residential R-96 and Rural Residential-2 lots are capped at thirty-five percent, Multiple Family Residential at forty-five percent, and commercial and industrial zones such as General Commercial and Light Industrial reach seventy-five percent.

By contrast, resource-protection zones including Exclusive Agriculture, Primary Agriculture, General Agriculture and the various Rural Remote and Rural Agriculture districts show a dash in the Maximum Coverage column, meaning the county imposes no percentage cap on those parcels at all; bulk there is controlled instead through minimum lot size, ranging from two to one hundred twenty acres, and setbacks. Rural Development, Rural Activity Center and Rural Farmworker Community zones split the difference: coverage is limited to twenty percent generally, but development condition 3 allows an additional fifteen percent, up to sixty percent, for townhouse, multi-family and non-residential uses if at least twenty percent of the lot stays landscaped.

Any coverage figure applies alongside the same table's front, side and rear setback columns and the height limit in the same row, so a building permit application must satisfy all three at once. Community Development reviews compliance at building permit and site plan stages under WWCC Title 14.