King County Council adopts revised school-impact fee formula, limits fees on some multifamily units

SEATTLE — The Metropolitan King County Council voted 8–1 on Aug. 26, 2025, to adopt a revised ordinance changing how the county calculates school impact fees, adding lower maximum fees for some multifamily units, codifying an affordable-housing exemption allowed under state law and requiring a future evaluation of the new formula.

The ordinance, proposed substitute ordinance 2025-0127, responds to a 2023 state law that requires jurisdictions that charge school impact fees to account for smaller units when calculating fees. Councilmember Susie Mosqueda, who led the package of amendments, said the changes aim to reduce the cost pressure on developers building family-sized multifamily units while preserving funding for school construction.

The council’s action matters because school impact fees pay for school capital projects and because the county is trying to balance those capital needs with incentives to produce “missing middle” family-sized housing. The final ordinance changes the county’s fee schedule, establishes a cap on certain multifamily fees, clarifies the affordable-housing exemption process, and requires housing-impact…