St. Pete Beach

Pinellas County regulates accessory dwelling units on parcels in unincorporated Pinellas through the Pinellas County Land Development Code (LDC), administered by Pinellas County Development Review Services. Pinellas is Florida's densest county — approximately 3,400 persons per square mile — and unincorporated pockets are small, irregularly shaped, and often surrounded by incorporated city limits (St. Petersburg, Clearwater, Largo, Pinellas Park, Dunedin, Tarpon Springs, and 18 other municipalities). § 163.31771 FS is permissive only; Pinellas's ADU framework arises entirely from local zoning and is meaningful chiefly for the narrow slice of unincorporated parcels. St. Petersburg runs its own ADU ordinance (city-level) that is among the most active in Florida.

• Pinellas County Land Development 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; if enacted, by-right ADUs in single-family zones would be required statewide with a December 1, 2026 local compliance deadline. Until then, Pinellas retains full discretion.

Pinellas County administers coastal, flood, historic, and airport overlays that cut across incorporated and unincorporated jurisdictions. The county's peninsular geography and barrier-island exposure make coastal construction and flood-hazard overlays especially consequential for ADUs — the majority of Pinellas parcels west of US 19 carry AE or VE flood-zone designations.

• FEMA Special Flood Hazard Areas (SFHA) — Pinellas is heavily flood-mapped. VE (velocity / wave) zones occupy the immediate shoreline of the Gulf barrier islands; AE zones extend inland across most of the western half of the county. ADUs in VE zones require pile-foundation or breakaway-wall construction with finished floor above BFE; AE-zone ADUs require elevation, flood vents, and flood-resistant materials. This is often the largest single cost driver for a coastal-Pinellas ADU project.
• Coastal Construction Control Line (CCCL) — The Florida DEP maintains a CCCL seaward of which new construction requires a state CCCL permit in addition to local permits. Portions of Pinellas's Gulf-front parcels (mostly in incorporated beach municipalities) are seaward of the CCCL; an ADU on such a parcel adds a state permit step with engineered-foundation review.
• St. Petersburg-Clearwater International Airport Noise & Approach Overlay — Parcels under the approach/departure surfaces of PIE face height restrictions and, in some cases, noise-attenuation construction requirements. A two-story ADU may be affected where a one-story primary dwelling is not.
• Historic Districts & Individually-Listed Historic Resources — Several Pinellas municipalities operate historic preservation boards with design-review authority over exterior alterations and new construction in mapped historic districts. A detached ADU in a historic district typically requires Certificate of Appropriateness (COA) review in addition to the standard building permit; this is a city-level process but is noted here because it cuts across the municipal boundary pattern.
• Wildland-Urban Interface (WUI) — Practical WUI exposure in densely urbanized Pinellas is limited; the provision is noted for completeness. Pinellas's larger insurance-underwriting pressure is hurricane-wind and storm-surge, not wildfire.

Permits for ADUs on parcels in unincorporated Pinellas County are issued by Pinellas County Development Review Services. Because unincorporated territory is fragmented and often adjoins city limits, pre-application confirmation of jurisdiction (city vs. county) is the critical first step — a parcel a block from an incorporated boundary is commonly misclassified by applicants. Incorporated cities inside Pinellas (St. Petersburg, Clearwater, Largo, Pinellas Park, Dunedin, Tarpon Springs, Oldsmar, Safety Harbor, Seminole, Gulfport, Madeira Beach, Treasure Island, Redington Beach, Redington Shores, North Redington Beach, Indian Shores, Indian Rocks Beach, Belleair, Belleair Beach, Belleair Bluffs, Belleair Shore, Kenneth City, South Pasadena, St. Pete Beach) handle their own ADU permits.