Lookout Mountain

Hamilton County, TN (373,000 residents including Chattanooga - distinct from Hamilton County, OH and Hamilton County, IN) operates a county zoning ordinance for unincorporated territory. The City of Chattanooga and other incorporated municipalities (East Ridge, Red Bank, Soddy-Daisy, Signal Mountain, Lookout Mountain, Collegedale) set their own rules.

• Hamilton County Zoning Ordinance
• Chattanooga Zoning Ordinance

State-floor overlay: No TN statewide ADU preemption.

Hamilton County administers flood-hazard, and (where mapped) coastal, wildland-fire, historic, and airport overlays that shape ADU project feasibility. The most consistent overlay across the county is FEMA NFIP floodplain regulation; other overlays apply to specific geographies inside the county.

• FEMA NFIP Special Flood Hazard Areas in Hamilton County — A new ADU in a mapped SFHA must be elevated to or above the Base Flood Elevation; cost impact on the project is often material.
• Historic districts and individually-listed historic resources

Hamilton County issues building permits for parcels in unincorporated territory through its development services / planning department, with separate review tracks for zoning conformance, building-code compliance, on-site sewage where applicable, floodplain compliance, and addressing. Inside incorporated municipalities, city departments handle their own permits; the county's authority is geographically limited to unincorporated territory. An ADU permit application is typically processed as a residential building permit with a zoning verification step against the county's ordinance for the parcel's zoning district.