DeKalb County handles permitting for all unincorporated areas, while incorporated cities like Decatur, Brookhaven, and Dunwoody manage their own independent building and zoning departments. Development in unincorporated areas is subject to specific overlay districts, including the DeKalb County Watershed Management requirements and various neighborhood conservation districts.
How this fits with the state
The state authority here is GA State Licensing Board. The county file does not replace that — it adds the permit office, local overlays, and the actual filing path.