St. Petersburg, FL Accessory Structures: ADU Rules (2026)
ADU rules in St. Petersburg, FL, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.
Key Facts
- Code section
- Sec. 16.50.010
- Min lot size NT
- 4,500 sq ft
- Floor area cap
- 40% of combined
- Authorizing ord.
- Ord. 509-H
- Mailing address
- Shared only
Summary
St. Petersburg permits accessory dwelling units in many residential districts under Land Development Regulations Sec. 16.50.010, with size, lot, parking, and design rules expanded by Ordinance 509-H.
requiring, rather than authorizing, local governments to adopt, by a specified date, an ordinance to allow accessory dwelling units in certain areas; authorizing a local government to provide a density bonus incentive to landowners who make certain real property donations to assist in the provision of affordable housing for military families; requiring the Office of Program Policy Analysis and Government Accountability to evaluate the efficacy of using mezzanine finance and the potential of tiny homes for specified purposes, etc.
Full Breakdown
Sec. 16.50.010 of Chapter 16 Land Development Regulations governs accessory dwelling units in St. Petersburg. ADUs are allowed in NS, NT, and NSM neighborhood districts following Ordinance 509-H adopted in 2022 and supported by Florida Statute 163.31771. Lots in NT districts must be at least 4,500 square feet, and the primary residence must contain at least 60 percent of the combined living area while the ADU is capped at 40 percent. ADUs may be attached, detached, or above a garage and require their own kitchen, bathroom, and entrance. Separate mailing addresses are prohibited and short-term rental of ADUs is restricted by city vacation rental rules. Owners must obtain zoning and building permits, meet setbacks, parking, and height standards, and comply with the Florida Building Code.
Violations & Fines
Building or renting an ADU without permits, exceeding the 40 percent floor area cap, or assigning a separate mailing address can trigger code enforcement action, daily fines, stop-work orders, and required removal or modification.
Frequently Asked Questions
Can I add a backyard ADU to my St. Petersburg home?
Can my ADU have its own mailing address?
Sources & Official References
Other rules in St. Petersburg
How St. Petersburg compares: Easiest Cities to Build an ADU·Florida rules heatmap·Compare St. Petersburg to another location·View the Florida accessory structures overview
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ADU Rules in Nearby Cities
How other cities in Pinellas County handle adu rules.