The county handles building permits for unincorporated areas, while incorporated municipalities like Rockford, Machesney Park, and Loves Park maintain their own independent building departments and permit processes. Unincorporated areas are subject to specific county zoning ordinances and flood hazard area regulations managed by the Regional Planning Department.
The county enforces a specific Stormwater Management Ordinance that requires detailed drainage plans for most new construction and significant site improvements in unincorporated areas.
How this fits with the state
The state authority here is Illinois IDFPR; Illinois Department of Public Health; local building departments. The county file does not replace that — it adds the permit office, local overlays, and the actual filing path.
Source · Winnebago County Regional Planning and Economic Development DepartmentLast verified · 05 / 2026