The City of Mobile and several other incorporated municipalities within Mobile County operate their own building permit and zoning departments. The county's Planning and Zoning Department handles unincorporated areas. Coastal flood zone reviews are common due to proximity to the Gulf of Mexico.
How this fits with the state
The state authority here is Alabama Licensing Board for General Contractors; Alabama Home Builders Licensure Board. The county file does not replace that — it adds the permit office, local overlays, and the actual filing path.