Jacksonville

Duval County is consolidated with the City of Jacksonville under the Jacksonville consolidated city-county government adopted by referendum in 1967 (Chapter 67-1320, Laws of Florida). Jacksonville's jurisdiction covers essentially all of Duval County except four small independent incorporated beach towns (Atlantic Beach, Neptune Beach, Jacksonville Beach, Baldwin) that retained separate municipal governments at consolidation. As a practical matter, there is NO separately-governed unincorporated Duval County — zoning, building, assessment, and overlay administration are all performed by the City of Jacksonville's departments for 98%+ of Duval parcels. ADU allowance flows from Jacksonville's Zoning Code (Chapter 656 of the Ordinance Code) and the Unified Development Code / Land Development Procedures Manual. § 163.31771 FS is permissive only.

• City of Jacksonville Ordinance Code, Chapter 656 — Zoning Code
• Florida Statutes § 163.31771 — Accessory Dwelling Units

State-floor overlay: No Florida statewide ADU preemption floor exists as of April 2026. SB 48 / HB 313 (2026 session) is the active preemption bill. Duval/Jacksonville retains full discretion until enactment.

Duval/Jacksonville administers flood, coastal, JAX airport-approach, military-base AICUZ, historic-district, and tree-protection overlays. The St. Johns River bisects the consolidated city-county and produces extensive AE-zone flood mapping; Atlantic-front and Intracoastal parcels carry VE/AE exposure; Naval Air Station Jacksonville and Naval Station Mayport generate federal AICUZ overlays.

• FEMA Special Flood Hazard Areas (SFHA) — AE zones are extensive along the St. Johns River, its tributaries (Trout River, Arlington River, Ortega River), and the Intracoastal Waterway. VE zones affect the narrow Atlantic frontage at Mayport and along the beach-city boundaries. ADUs in SFHA require elevation, flood vents, and flood-resistant materials.
• Coastal High Hazard Area (CHHA) — Atlantic-adjacent Duval parcels fall within CHHA with heightened comprehensive-plan review on intensification of residential use.
• Naval Air Station Jacksonville (NAS JAX) & Naval Station Mayport AICUZ — Air Installation Compatible Use Zones around NAS JAX (Ortega/Westside) and NAS Mayport (East Duval) restrict residential intensification in mapped APZ areas and require noise-attenuation construction in noise zones. ADUs in APZ-I or APZ-II may be prohibited; APZ noise zones add construction cost.
• Jacksonville International Airport (JAX) Approach Zones — Parcels under JAX approach/transitional surfaces face height restrictions; a two-story ADU may require FAA Form 7460 notice.
• Historic Districts (Springfield, Riverside, Avondale, San Marco, others) — Jacksonville maintains several locally-designated historic districts and is active with the State Historic Preservation Office. A detached ADU in a historic district requires Certificate of Appropriateness (COA) review by the Jacksonville Historic Preservation Commission in addition to the standard building permit.
• Tree-Protection Overlay — Jacksonville's tree-protection ordinance applies city-wide. A tree-removal permit is required for any protected-species removal; ADU siting that necessitates protected-tree removal adds a permit step and potential mitigation cost.

Permits for ADUs anywhere in Duval County outside the four independent beach municipalities are issued by the City of Jacksonville Planning and Development Department (zoning review) and the Building Inspection Division (building review). Jacksonville operates the largest single-jurisdiction permitting office in Florida by land area (~875 square miles). The Unified Development Code governs the procedural path, and the Jacksonville ePermit / Citizen Access portal handles intake, review, and inspection scheduling.