Can you build an ADU on your St. Pete lot?
Enter your address for an instant read on your flood zone and ADU zoning — then get a free written feasibility study for your exact parcel.
St. Pete ADU Zoning Map, Explained: Can You Build?
The number one question we hear isn’t “how much?” — it’s “am I even allowed?” St. Petersburg has some of the most ADU-friendly rules in Florida, but the zoning map (NT-1 vs NT-2 vs NS) trips people up. Here’s the plain-English version, current as of 2026.
1. The 5-foot setback rule
This is usually the make-or-break. A detached ADU generally must sit at least 5 feet from your rear and side property lines (NS zones require ~10 ft on the side).
- Detached unit: ~5 ft from sides and rear.
- Garage conversion: if your garage already sits closer than 5 ft (common in Historic Kenwood), you’re usually grandfathered in — as long as you don’t expand the footprint.
- Second story (over a garage): setbacks often increase — plan for it.
2. Impervious Surface Ratio (ISR)
St. Pete cares about drainage. Your impervious surfaces combined — house + driveway + pool + ADU — generally can’t cover more than 60–65% of the lot.
3. Size limits
Your ADU can’t exceed 800 sq ft or 67% of the main house, whichever is smaller. Coastal/flood lots can be capped smaller.
4. Flood zone — the hidden cost driver
Much of St. Pete sits in a FEMA flood zone. If your lot is in a high-risk zone (AE or VE), the ADU foundation must be elevated, which adds cost. Zone X lots avoid that. The quick-check above pulls your real FEMA zone in seconds so there are no surprises.
5. Fees you can expect (preliminary)
St. Pete keeps ADU fees relatively light — it collects only a transportation impact fee (no city parks or school impact fees):
- Transportation (multimodal) impact: roughly $1,356 (suburban) / $1,003 (downtown) — a prior-use credit can reduce it.
- Sewer impact: $1,000 per water closet · Water connection: ~$1,396 (standard meter).
- Building permit: $7 per $1,000 of value (flat $250 for a unit ≤1,400 sf) + $50 review + $75 certificate of occupancy.
Figures are preliminary and confirmed at permitting. This is a feasibility guide, not a construction quote — the build price is set after design.
Don’t guess — check your lot
The city map is confusing and the rules apply to your exact parcel. Run your address through the quick-check above for an instant read, and we’ll follow up with a free written feasibility study confirming what you can build and the next step: architectural design and permitting.