Spring Hill

Hernando County portion

ADU Pass helps homeowners in Spring Hill, Hernando County, Florida navigate the permit paperwork for building an accessory dwelling unit. This area covers 3 ZIP codes.

3 ZIP codes

ADU details

ADU legality: allowed-with-restrictions

Statewith-restrictions (Florida accessory-dwelling framework) — § 163.31771 FS is permissive; local jurisdictions retain full authority. SB 48 / HB 313 (2026 session) would broaden preemption if enacted.
Countyallowed (Hernando County unincorporated zoning) — Hernando County permits ADUs in unincorporated areas under state-law-aligned standards. Spring Hill is entirely unincorporated and falls under Hernando County jurisdiction.
Cityallowed (City of Spring Hill Land Development Code / zoning) — Spring Hill is unincorporated; all permits through Hernando County (no city government). Verify HOA status before designing — a meaningful minority of subdivisions restrict ADUs.

Spring Hill is one of Florida's largest unincorporated CDPs (population ~110,000) and has no city government — all ADU permits are issued by Hernando County. The community sits on the Suncoast Parkway in the Tampa commute shed.

Cost scenarios

ScenarioSq ft PermitBuildTotal
minimum 150 $2,400 $31,500 $33,900
600 600 $2,400 $126,000 $128,400
midpoint 575 $2,400 $120,750 $123,150
maximum 1,000 $2,400 $210,000 $212,400
Fee breakdown
Plan review$720
Building permit$1,320
Impact fees$360
Total$2,400

Viability (permitted uses)

  • Long-term rental: yes Long-term rental of ADU generally permitted; landlord-tenant law applies.
  • Short-term rental: with-restrictions Spring Hill STR rules — check minimum-stay limits, registration, and HOA covenants.
  • Office rental: with-restrictions Detached office rental requires home occupation permit.
  • Home office: yes Home occupation permitted with restrictions on signage and customer traffic.
  • Studio / workshop: yes Personal artist studio is a permitted accessory use.
  • Agriculture: with-restrictions Limited urban agriculture permitted in residential zones; livestock varies by district.
  • Relative support: yes Family-occupancy ADU explicitly permitted; § 193.703 FS granny-flat assessment reduction available.

Utilities

  • Water: City of Spring Hill Water Utility · 30d connect · $4,500
  • Sewer: City of Spring Hill Wastewater · 30d connect · $5,500
  • Electric: Duke Energy Florida / Talquin Electric Cooperative / FPL (varies) · 21d connect · $1,800
  • Gas: Propane · 30d connect · $1,500

Property values & taxes

Median value$295,000
Median tax$2,655/yr
Effective rate0.9%

Construction timeline

Detached build22 weeks
Conversion12 weeks
Contractor lead3 months

Realistic total: best 7mo · typical 11mo · worst 16mo

Financing

Fannie Mae ADUeligible

State ADU loans:

Insurance impact

Annual premium delta$720
Landlord policyrecommended
Umbrella threshold$1M umbrella when renting

HOA prevalence & preemption

State HOA preemptionno

Florida has no HOA-ADU preemption; HOA covenants restricting ADUs are enforceable.

Regulatory overlays (2)

  • flood-zone
    Limited FEMA AE pockets along Weeki Wachee River and coastal Gulf shoreline; most subdivision lots are upland.
  • sinkhole-zone
    Karst geology; sinkhole insurance offer statutory.
Technical envelope (climate & building code)

Climate & energy code

IECC climate zone2A
Heating degree days1,100
Cooling degree days3,200
Design low / high38°F / 93°F
Wind design speed140 mph
Seismic design cat.A
Annual rainfall53"
Wildfire exposurelow
Energy codeIECC
Version / adopted2020 / 2024

Building code

Base codeIRC
Version year2,020
Adopted2024
Fire sprinklernone
Egress window5.7 sqft min
Min ceiling7 ft
Attic R-valueR-38 min
Wall R-valueR-13 min

Amendments:

  • Amendment
  • Amendment

Known issues (4)

  • issue
  • issue
  • issue
  • issue
Hernando County — county ADU rules and overlays

County ADU ordinance

Hernando County regulates accessory dwelling units on parcels in the unincorporated county through the Hernando County Land Development Code (LDC), which addresses 'accessory residential structures,' 'guest houses,' and 'caretaker dwellings.' Florida has no mandatory statewide ADU preemption — § 163.31771 Fla. Stat. is permissive only. Hernando is a rural-to-suburban Gulf Coast county north of Tampa Bay, covering 589 square miles, centered on Brooksville (county seat, inland) and Spring Hill (largest unincorporated community, ~116,000 residents — one of Florida's largest unincorporated communities). The coastal Weeki Wachee / Hernando Beach / Aripeka strip is surge-exposed. As of 2026-04-20, Hernando County permits one accessory residential structure / guest house per single-family parcel in most residential zoning districts (R1-A, R1-B, R1-C, PDP-R) subject to size caps (typically 750 sqft or 40% of primary, whichever is less; larger allowances on A/RR agricultural and rural parcels), setback conformance, height limits, and utility-sharing requirements. Hurricane Helene (Sept 2024) and Hurricane Milton (Oct 2024) both impacted Hernando's Gulf coastal fringe with surge damage to Aripeka, Hernando Beach, and the Weeki Wachee waterfront. Pending 2026 state legislation (SB 48 / HB 313) would preempt sub-1,000-sqft caps — Hernando's 750-sqft cap would need upward adjustment.

State-floor overlay: Florida has no mandatory statewide ADU preemption. § 163.31771 Fla. Stat. is permissive only. Pending 2026-session SB 48 / HB 313 would preempt sub-1,000-sqft caps and single-family-zone bans effective December 1, 2026 if enacted. Hernando's 750-sqft cap requires upward adjustment. Live Local Act applies to commercial / industrial / mixed-use. Florida HOA, condominium, and cooperative statutes (Ch. 720, 718, 719) do NOT preempt association-level restrictions — Hernando has many HOA-governed subdivisions (Glen Lakes, Timber Pines, Silverthorn, Sterling Hill, Barony Woods) where covenants bar ADUs.

County regulatory overlays

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.

County permitting (unincorporated parcels)

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.

DepartmentHernando County Development Services Department
Address789 Providence Blvd, Brooksville, FL 34601
Phone352-754-4050
Florida state — ADU law and programs

State ADU law

Florida does NOT currently have a statewide ADU preemption law in effect. Florida Statutes § 163.31771 (enacted 2004, last amended 2020) is permissive — it authorizes local governments to adopt ADU ordinances but does not require them to. ADU rules are therefore set municipality-by-municipality: Miami-Dade, Orlando, St. Petersburg, Tampa, and a growing set of Florida cities have their own ordinances; many smaller counties and cities still prohibit or restrict ADUs by default. A preemption bill (SB 48 / HB 313) is pending in the 2026 legislative session and is likely to pass given that its 2025 predecessor cleared the Senate 37-0 and House 97-10 before dying on a procedural amendment dispute.

  • Florida Statutes § 163.31771 — Accessory dwelling units — Permissive (not mandatory) statute. Defines an ADU as 'an ancillary or secondary living unit, that has a separate kitchen, bathroom, and sleeping area, existing either within the same structure, or on the same lot, as the primary dwelling unit.' Authorizes — but does not require — local governments to adopt ordinances allowing ADUs in single-family residential zones. Contains no size caps, no owner-occupancy rules, no HOA preemption. All substantive rulemaking is local.

State financing programs

Florida Housing Finance Corporation (FHFC) does not operate an ADU-specific state loan or grant program. FHFC's primary affordable-housing lever at the ADU tier is the State Housing Initiatives Partnership (SHIP), which distributes state documentary-stamp-tax revenue to all 67 counties and 52 entitlement cities for locally-administered housing programs — some of which may fund ADU construction at the local level (notably Orange County's Affordable ADU Loan Program, run through the Orange County Housing Finance Trust). FHFC's FL Assist down-payment programs and HFA Preferred / HFA Advantage conventional loans apply to ADU-eligible primary residences but do not single out ADUs. Proposed CS/SB 1440 would create a state property-tax exemption of up to 100% of assessed value for an ADU rented at affordable rates.

State housing programs

Florida does not currently operate a statewide pre-approved ADU plan catalog (unlike California or Washington). State-level ADU implementation is driven by (a) the permissive § 163.31771 which lets willing jurisdictions adopt ordinances, (b) SHIP pass-through funding to local ADU programs (Orange County's Affordable ADU Loan Program is the model), and (c) the affordable-housing property-tax exemption under the Live Local Act (SB 102 / SB 328). The Department of Economic Opportunity (DEO) — now reorganized as the Department of Commerce — provides technical assistance to local governments but no statewide ADU-specific mandate or program. Major counties (Miami-Dade, Orange, Pasco, Hillsborough, Pinellas, Broward) have published their own ADU ordinances and guidance documents.

Federal (United States) — ADU-relevant rules and programs

Federal ADU law

The United States has no federal statute that directly regulates accessory dwelling unit entitlement or design. Land-use authority over ADUs resides with states and local governments under the traditional police power. Federal engagement is limited to financing (Fannie/Freddie/FHA/VA/USDA), flood insurance (FEMA/NFIP), and discretionary housing programs (HUD), which are recorded in sibling sections of this file.

Federal financing programs

Federal housing-finance agencies and GSEs set nationwide underwriting rules that govern whether an ADU can be financed, appraised, and counted toward mortgage qualifying income. The relevant actors are Fannie Mae, Freddie Mac, FHA (HUD), VA, and USDA Rural Development.

Federal tax credits

There is no ADU-specific federal tax credit. ADUs may incidentally qualify for existing federal energy-efficiency and clean-energy tax credits when the ADU construction includes qualifying measures.

Federal housing programs

HUD administers several discretionary programs that can fund ADU-related activity at the grantee's election, but none is an ADU-specific program.

ZIP Codes

  • 34606
  • 34607
  • 34608

Post Office

  • 8501 Philatelic Dr, 34606