The Santa Rosa ADU WUI Shift That Can Add $10K to $25K After Design Starts

WUI shift can add $10K-$25K and 2-8 weeks in Santa Rosa. Check the updated boundary before design starts.

Santa Rosa's updated WUI boundary is now the ADU check that matters first. Cal Fire released the 2025 LRA Fire Hazard Severity Zone maps on February 24, 2025. Santa Rosa City Council then adopted the City's updated Wildland Urban Interface boundary on second reading on June 2, 2026, with the new boundary expected to take effect around July 2, 2026. If your parcel falls inside that updated WUI area and nobody catches it until after design starts, the project can pick up $10K to $25K in upgraded exterior assemblies plus 2 to 8 weeks of rework. That is not a late plan check nuisance. That is a…