Hernando County

Hernando County Development Services Department (Building Division + Planning) is the combined planning / zoning / building / floodplain permit authority for parcels in the unincorporated county. Unincorporated Hernando covers approximately 460 square miles (about 78% of county land area). Incorporated municipalities are Brooksville (county seat) and Weeki Wachee (tiny — the 'smallest city in Florida'). Most of the county's population lives in unincorporated Spring Hill (~116,000), Hernando Beach, Weeki Wachee Gardens, Aripeka, Ridge Manor, Istachatta, and Nobleton. Hernando is a CRS Class 6 community for NFIP. All of Hernando County is in Wind Borne Debris Region (WBDR) at 150 mph ultimate (inland) or 160 mph (coastal/Hernando Beach). Development Services operates a single permit counter combining zoning, building, floodplain, and environmental review.

Process overview: Accessory residential structure approval in unincorporated Hernando County is a combined zoning / building / floodplain / septic review. Typical sequence: (a) confirm parcel zoning, FLU, CHHA, FIRM via Property Appraiser and Development Services GIS; (b) submit Building Permit through EnerGov with site plan, floor plans, elevations, FBC compliance (150-160 mph ultimate per location), flood compliance for SFHA, DOH septic approval; (c) zoning review; (d) building plan review; (e) Hernando County Fire Rescue access/water review; (f) permit issuance, construction, inspections, CO. Target 20-30 business days for residential review; actuals 35-60 business days post-Helene/Milton on coastal parcels.

Impact fees: Hernando County impact fees (transportation, parks, law enforcement, schools) total approximately $6,000-$10,000 for a typical ADU (as of 2026-04-20). Water/sewer connection fees through Hernando County Utilities in served areas add $3,000-$6,000; septic/well parcels pay no connection fee. No ADU-specific impact-fee exemption. (schedule)

Hernando County Property Appraiser maintains parcel-level assessment records. Florida Save Our Homes (§ 193.155) / 10% non-homestead cap apply. ADU treated as new construction added to just value at completion-year fair market value; primary's SOH base not reset. Post-Helene / Milton, Property Appraiser issued § 197.319 prorated tax refunds on destroyed coastal residences.

Assessment policy: New-construction additions occur at annual roll following CO. Field-inspection cycle typically 6-12 months. Typical 600-900 sqft accessory dwelling adds $65,000-$120,000 just value, yielding supplemental annual tax of $1,100-$2,100 at aggregate millage ~1.65-1.85%.

Hernando County administers overlays materially affecting ADU siting: (1) FEMA SFHA along Gulf frontage (Aripeka, Hernando Beach, Weeki Wachee Gardens waterfront) and inland along the Withlacoochee River / Weeki Wachee River / Chassahowitzka River corridors; Hernando is CRS Class 6; post-Helene / Milton FIRM revisions raised BFEs on affected coastal segments; (2) Florida Building Code Wind Borne Debris Region at 150-160 mph ultimate; (3) Coastal High Hazard Area (CHHA) under Comp Plan — post-storm intensification policies tightened; (4) Florida DEP Coastal Construction Control Line on Gulf shoreline; (5) Withlacoochee State Forest Firewise zones in eastern Hernando; (6) Karst / sinkhole geotechnical overlay similar to Marion/Citrus counties — Hernando is Eocene Ocala Limestone karst country; (7) Southwest Florida Water Management District (SWFWMD) consumptive-use and stormwater; (8) Florida Aquatic Preserves — Weeki Wachee Spring, Chassahowitzka waters.

• FEMA Special Flood Hazard Areas (SFHA) — NFIP (Hernando CRS Class 6, post-Helene/Milton FIRM) — Hernando administers FEMA NFIP. SFHA covers Gulf coastal strip and river corridors. CRS Class 6 gives 20% NFIP premium discount. Post-Helene / Milton FIRM revisions raised BFEs on coastal segments.
• Florida Building Code Wind Borne Debris Region (WBDR) — 150 mph inland / 160 mph Gulf-coastal Hernando. Impact-rated glazing or shutters required.
• Coastal High Hazard Area (CHHA) — Hernando Comp Plan (post-storm tightened) — CHHA covers Aripeka / Hernando Beach / Weeki Wachee waterfront. Post-storm policies substantially tightened intensification restraint.
• Florida Coastal Construction Control Line (CCCL) — FDEP — CCCL along Gulf shoreline. CCCL permit adds 60-120 days to timeline.
• Karst / Sinkhole Geotechnical Overlay — Hernando is Ocala Limestone karst country. Geotechnical investigation required on parcels in identified karst-risk zones. Typical cost $1,500-$5,000; sinkhole-feature parcels require foundation modifications.
• Withlacoochee State Forest Firewise Zones — Withlacoochee State Forest occupies portions of eastern Hernando. Firewise zones along forest interface drive insurance-focused defensible-space expectations.
• Florida Aquatic Preserves — Weeki Wachee, Chassahowitzka — Weeki Wachee Spring and Chassahowitzka waters are state-designated. Waterfront accessory structures require FDEP / SWFWMD permitting for in-water work.