ADU Pass
Hobe Sound
Martin County portion
Also in: No County
ADU Pass helps homeowners in Hobe Sound, Martin County, Florida navigate the permit paperwork for building an accessory dwelling unit. This area covers 1 ZIP code.
Map
ADU details
ADU legality: allowed-with-restrictions
Florida has no statewide ADU preemption; local ordinance is the binding constraint. Hobe Sound permits ADUs subject to local conditions.
Cost scenarios
| Scenario | Sq ft | Permit | Build | Total |
|---|---|---|---|---|
| minimum | 150 | $3,200 | $48,000 | $51,200 |
| 600 | 600 | $3,200 | $192,000 | $195,200 |
| midpoint | 575 | $3,200 | $184,000 | $187,200 |
| 1000 | 1,000 | $3,200 | $320,000 | $323,200 |
| maximum | 1,000 | $3,200 | $320,000 | $323,200 |
Fee breakdown (as of 2026-04)
Permitting process
Viability (permitted uses)
- Long-term rental: yes Long-term rental of ADU permitted; Florida Ch. 83 landlord-tenant law applies.
- Short-term rental: with-restrictions STR rules vary; Hobe Sound STRs subject to Martin County vacation-rental ordinance and Florida DBPR licensing.
- Office rental: with-restrictions Detached office rental requires home occupation permit or rezoning.
- Home office: yes Home occupation permitted with conditions on signage and traffic.
- Studio / workshop: yes Personal artist/maker 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 in residential zones.
Contacts
Utilities
- Water: Martin County Utilities · 30d connect · $4,500
- Sewer: Martin County Utilities (where served) / septic outlying · 30d connect · $5,500
- Electric: Florida Power & Light (FPL) · 21d connect · $1,800
- Gas: TECO Peoples Gas / propane · 14d connect · $1,500
Property values & taxes
Construction timeline
Realistic total: best 8mo · typical 12mo · worst 17mo
Modular pathway inspectors are occasional with modular
Standard transport with permitted oversize loads
Financing
State ADU loans:
Insurance impact
Coastal Florida wind+flood premiums elevated; sinkhole rider may also apply.
HOA prevalence & preemption
Florida Ch. 720 HOA, Ch. 718 condo, and Ch. 719 cooperative statutes do not preempt HOA-level ADU bans. Recorded covenants control where they exist.
Regulatory overlays (2)
- flood-zone
Hobe Sound has FEMA Special Flood Hazard Areas (AE/VE/AO/X-shaded). Lowest-floor elevation to BFE + Martin County freeboard required; FEMA Elevation Certificate at CO. NFIP flood insurance effectively mandatory for coastal mortgaged parcels. - coastal-commission
Coastal Construction Control Line (CCCL) jurisdiction may apply for parcels seaward of the line; FDEP CCCL permit required for accessory structures.
Technical envelope (climate & building code)
Climate & energy code
Building code
Amendments:
- Amendment
- Amendment
Contractor market (aggregate)
Legal history (timeline)
Current ordinance: Martin County Land Development Code — Accessory Dwellings, adopted 2010-01-01, last amended 2024-01-01
- 2024-01-01 — Florida Building Code 8th Edition update (building-code)
Statewide adoption of FBC 8th Edition (IECC 2020 base with Florida amendments).
Effect: Updated wind, energy, and structural standards apply to new accessory dwellings
Martin County — county ADU rules and overlays
County ADU ordinance
Martin County regulates accessory dwelling units on parcels in the unincorporated county through the Martin County Land Development Regulations (LDR), which address 'Accessory Dwelling Units' and 'guest houses.' Martin County's most distinctive regulatory feature is its famous 4-story (40-foot) maximum height cap across nearly all residential zoning districts in most of the county — a long-standing local policy that has resisted multiple development-pressure waves since adoption in the 1980s. The cap reflects the county's small-town / Treasure Coast identity and has been codified in the Comprehensive Growth Management Plan. As of 2026-04-20, Martin County permits one ADU per single-family parcel in most residential zoning districts subject to size caps (typically 800 sqft or 50% of primary, whichever is less), the 4-story height cap (effectively 25-35 feet for residential in most districts, well below the 40-foot ceiling), setback conformance, and owner-occupancy. Martin County is a wealthy Atlantic-coast county (Stuart is the county seat, on the St. Lucie Inlet; Jensen Beach, Hobe Sound, Palm City, Port Salerno, Indiantown are the principal other communities). The county has extensive Indian River Lagoon / St. Lucie River / Loxahatchee River frontage and Atlantic coastal frontage including Hutchinson Island. Florida has no mandatory statewide ADU preemption — § 163.31771 Fla. Stat. is permissive only. Pending 2026 state legislation (SB 48 / HB 313) would preempt sub-1,000-sqft caps — Martin's 800-sqft cap requires upward adjustment.
- Martin County Land Development Regulations (LDR) — Accessory Dwelling Unit provisions
- Martin County Comprehensive Growth Management Plan — Future Land Use Element
- Martin County Board of County Commissioners — agenda archive
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. Martin's 800-sqft ADU cap requires upward adjustment. Live Local Act (SB 102 2023 / SB 328 2024) has been an active friction point for Martin County because Live Local preempts local height limits on affordable-housing commercial projects — the Live Local vs. 4-story height-cap conflict has been litigated repeatedly. Live Local does not directly bear on single-family ADUs, however. Florida HOA, condominium, and cooperative statutes (Ch. 720, 718, 719) do NOT preempt association-level ADU restrictions — Martin County has extensive HOA / condominium jurisdiction on Hutchinson Island, Sailfish Point, Sewall's Point (its own municipality), Jupiter Island (its own municipality), and master-planned mainland communities (Heritage Ridge, Harbour Ridge, Mariner Sands, Piper's Landing, The Meadows at Martin Downs) where covenants commonly bar ADUs.
County regulatory overlays
Martin County administers or co-administers overlays materially affecting ADU siting: (1) FEMA SFHA covering Hutchinson Island (barrier island), Indian River Lagoon frontage, St. Lucie River system frontage, Loxahatchee River frontage, and Atlantic Gulf coast; Martin is CRS Class 5 giving 25% NFIP discount; (2) Florida Building Code Wind Borne Debris Region at 150-170 mph ultimate; (3) Coastal High Hazard Area (CHHA) under Martin Comp Plan; (4) Florida DEP Coastal Construction Control Line (CCCL) along Atlantic shoreline; (5) Indian River Lagoon Protection Zone — county-administered buffer protections supporting the lagoon-wide TMDL and restoration program; (6) Loxahatchee River Wild and Scenic River corridor — federally-designated in Martin County with extensive riparian protections; (7) South Florida Water Management District (SFWMD) consumptive-use and stormwater; (8) 4-story / 40-foot countywide height cap (Comp Plan-level, not a zoning overlay per se but functionally equivalent); (9) Martin County Agricultural Preservation Zone; (10) Witham Field (Stuart) AIA and Palm Beach International AIA extension (small overlap in south Martin).
- FEMA Special Flood Hazard Areas (SFHA) — NFIP (Martin CRS Class 5) — Martin administers FEMA NFIP. SFHA covers Hutchinson Island, Indian River Lagoon, St. Lucie River, Loxahatchee River, and Atlantic Gulf coast frontage. CRS Class 5 gives 25% NFIP premium discount.
- Florida Building Code Wind Borne Debris Region (WBDR) — 150 mph inland / 160-170 mph Atlantic-coastal and barrier-island. Impact-rated glazing or shutters required.
- 4-Story / 40-Foot Countywide Height Cap — Martin Comp Plan — Martin County's signature growth-management policy is a 4-story / 40-foot maximum height cap across nearly all residential and commercial zoning districts (with narrow exceptions in certain Stuart downtown zones). The cap is codified in the Comp Plan as a growth-management principle and has resisted multiple development-pressure waves since 1980s adoption. Live Local Act (SB 102 / SB 328) preempts local height limits on qualifying affordable-housing commercial-zone projects, which has created legal friction. For single-family ADUs, the 4-story cap is rarely binding since residential ADUs rarely exceed 2 stories.
- Coastal High Hazard Area (CHHA) — Martin Comp Plan — CHHA covers Hutchinson Island, Atlantic coastal frontage, and surge-exposed bayfront. Intensification restraint policies apply.
- Florida Coastal Construction Control Line (CCCL) — FDEP — CCCL along Atlantic shoreline. Seaward of CCCL requires FDEP permit adding 60-120 days.
- Indian River Lagoon Protection Zone — The Indian River Lagoon is a federally-designated estuary of national significance; its water-quality crisis (brown tide, seagrass loss, algal blooms) has driven extensive protection programs. Martin County's Lagoon Protection Zone imposes nutrient-loading controls, seagrass-habitat protections, and stormwater enhancements on lagoon-frontage parcels. ADUs on lagoon-frontage parcels face tightened stormwater / septic requirements.
- Loxahatchee River Wild and Scenic River corridor — The Loxahatchee River (shared with Palm Beach County) is one of only two federally-designated Wild and Scenic Rivers in Florida (the other being the Wekiva). Parcels in the Loxahatchee corridor face federal / state / SFWMD coordinated protection including setback buffers, riparian-vegetation preservation, and stormwater enhancements. ADUs in the corridor face tightened review.
- SFWMD consumptive-use and stormwater — SFWMD is Martin County's water management district. Standard residential consumptive-use exemption below ~6,000 gpd. ERP review for additions beyond minor footprint.
- Martin County Agricultural Preservation Zone — Martin County's agricultural-preservation zoning covers extensive western-county acreage (Indiantown area, Allapattah Flats region). Farm-worker housing is permitted as accessory agricultural use. Residential ADUs on agricultural-zoned parcels face density restrictions.
- Witham Field (SUA) Airport Influence Area — Witham Field is Martin County's primary GA airport. AIA affects parcels near Stuart. Part 77 and Part 150 reviews apply in AIA.
County permitting (unincorporated parcels)
Martin County Growth Management Department is the combined planning / zoning / building / floodplain / environmental permit authority for parcels in the unincorporated county. Unincorporated Martin covers approximately 440 square miles (about 81% of the county's 543 sqmi total land area). Incorporated municipalities are Stuart (county seat), Jupiter Island (wealthy enclave town), Sewall's Point (small town on the peninsula between St. Lucie and Indian Rivers), and Ocean Breeze (tiny). Principal unincorporated communities include Jensen Beach, Hobe Sound, Palm City, Port Salerno, Indiantown (partially incorporated as the Village of Indiantown since 2017), Rio, Tequesta unincorporated fringe (Tequesta proper is in Palm Beach County), North River Shores, and Hutchinson Island (partially unincorporated, partially within Stuart). Martin County is a CRS Class 5 community for NFIP (among the best in Florida). All of Martin County is WBDR at 150 mph inland / 160-170 mph barrier-island and immediate coastal. Growth Management operates a one-stop permit intake with sophisticated environmental review capability.
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 Code
- 33455
Post Office
- 9995 SE Federal Hwy, 33455