Pinellas County, FL Accessory Structures: ADU Rules (2026)
ADU rules in Pinellas County, FL, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.
Key Facts
- Governing section
- LDC Sec. 138-3210
- Max size
- 1,000 sq ft (750 in flood zones)
- Units per lot
- One accessory dwelling unit
- Occupancy
- Primary or ADU owner-occupied
- Scope
- Unincorporated Pinellas County only
Summary
Unincorporated Pinellas County caps accessory dwelling units at 1,000 square feet (750 in coastal storm or flood hazard areas), allows only one per lot, and generally requires the primary or accessory unit to be owner-occupied.
The accessory dwelling unit shall not exceed 1,000 square feet, or 750 square feet if the property is within the Coastal Storm Area or flood hazard areas established in Land Development Code Section 158-23... There shall be only one accessory dwelling unit per lot or parcel of ownership. Either the primary dwelling unit or the accessory dwelling unit shall be owner-occupied.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 124).
Full Breakdown
Sec. 138-3210 lets single-family homes in residential districts add one accessory apartment, garage apartment or guest house as an accessory dwelling unit. Size is capped at 1,000 square feet, dropping to 750 square feet within the Coastal Storm Area or mapped flood hazard areas, with a larger unit possible only through the Sec. 138-77 approval process. Only one ADU is allowed per lot, and either the primary or accessory unit must be owner-occupied unless both qualify as affordable housing under a 20-year land use restrictive agreement.
Violations & Fines
Adding a second accessory dwelling unit on one lot, exceeding the square-footage cap, or occupying neither unit as owner-occupied without an affordable-housing waiver is a zoning code violation subject to county code enforcement action.
Frequently Asked Questions
How big can an ADU be in unincorporated Pinellas County?
Can I have two accessory dwelling units on one lot?
Sources & Official References
Other rules in Pinellas County
How Pinellas County compares: Easiest Cities to Build an ADU·Florida rules heatmap·Compare Pinellas County to another location·View the Florida accessory structures overview
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