ADUs are allowed in Unincorporated St. JohnsTypes:DetachedInternal
Types:DetachedInternal
Accessory Dwelling Unit (ADU) Rules for Unincorporated St. Johns, FL
Is your property eligible for an ADU?
# of Properties
163,911
Owner-occupied
69%
Zoning districts
45
Avg Home Value
$518,639
Median Lot Size
0.23 acres
Avg Income
$120,157
Residential Types:
163,911 housing units
Single Family
74%
Apts (4+ units)
1%
Other
24%
Zoning Districts:
210,091 parcels · 45 districts
PUD
57%(118,849)
OR
13%(28,244)
RS-3
13%(27,386)
RS-2
3%(6,700)
Other
14%(28,912)
ADU Rules
What can you build in Unincorporated St. Johns, FL?
Unincorporated St. Johns, FL follows state and local rules for Accessory Dwelling Units. Here is a concise overview of the local rules.
Eligibility
- –Internal / Attached ADU: Conditional Use Permit
- –Detached ADU: Conditional Use Permit
Interior / Attached ADU Size Limits
- –Maximum size is the lesser of 2,000 sq ft or 35% of the main dwelling’s floor area, but never less than 800 sq ft.
Detached ADU Size Limits
- –Maximum size is the lesser of 2,000 sq ft or 35% of the main dwelling’s floor area, but the allowed maximum cannot be less than 800 sq ft.
Owner Occupancy
- –Main dwelling must be owner-occupied.
Parking
- –No fixed minimum; parking determined by County Administrator. AFU not a separate dwelling unit; additional parking, if required, must be on-site unless off-site/shared parking is approved by a Special Use Permit within 300 ft and a recorded reciprocal easement.
Rental Restrictions
- –Guest House/Guest Quarters/Cottage: unit shall not be rented; occupancy by the same tenant limited to 30 days per calendar year. Internal/Attached ADU (Accessory Family Unit): shall be non-rental.
ADU State Law
What can you build in Florida?
- –Florida does not have a statewide ADU mandate. There is no state-level requirement for cities or counties to allow ADUs.
- –ADUs in Florida are regulated entirely at the local level. Some jurisdictions allow ADUs broadly, others allow them with strict conditions, and some prohibit them altogether.
- –Florida Statute 163.31771 is optional. It allows local governments to adopt ADU ordinances for affordable housing, but it does not require any jurisdiction to allow ADUs, and local governments may adopt ADU rules outside of this statute.
- –County and city rules may differ. In unincorporated areas, county zoning controls whether ADUs are allowed; within city limits, municipal zoning codes apply.
What's allowed on your lot?
These are the municipality-wide rules. What's allowed on a specific property also depends on state laws, setbacks, floor area ratio, lot coverage, environmental constraints, topography, and other property-specific factors. Search your address on FutureLot to see what's allowed on your property.
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ADU rules in other Florida municipalities
Rules change at the town line. Check the municipality your property is actually in.
St. Johns County