Putnam County, FL Accessory Structures: ADU Rules (2026)
ADU rules in Putnam County, FL, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.
Key Facts
- Minimum lot size
- 1/2 acre (waived with central water/sewer)
- Minimum ADU size
- 375 sq. ft.
- Maximum ADU size
- 75% of home, cap 2,000 sq. ft.
- Bedroom limit
- 2, max 3 by special use permit
- Units allowed per lot
- One accessory dwelling unit
Summary
Unincorporated Putnam County allows one accessory dwelling unit by right on a single-family residential or agricultural lot, but caps its size, bedroom count and lot size, and it cannot be sold apart from the main house. The rules sit in the county's Land Development Code, not a separate ADU ordinance.
a.Definition. ... An "accessory dwelling unit" is a dwelling unit located on the same lot as the principal residential structure which may be separate from the principal residential structure or contained within it. Accessory dwelling unit shall be an allowed use in all single-family residential zoning districts, including Agriculture and agriculture estate, subject to the provisions listed below. ... h.The accessory dwelling unit shall be no smaller than 375 square feet and no larger than 75 percent of the enclosed square footage of the primary residence, not to exceed 2,000 square feet of enclosed living space. ... i.The accessory dwelling unit shall be limited to two bedrooms. A maximum of one additional bedroom for an accessory dwelling unit may be allowed if approved by a special use permit from the zoning board of adjustment. Under no circumstance will an accessory dwelling unit be permitted to have four or more bedrooms.
Full Breakdown
Putnam County Code § 45-110(6) defines an accessory dwelling unit as a dwelling unit on the same lot as the principal residence, either attached or detached, allowed by right in every single-family residential zoning district, including Agriculture and Agriculture Estate, and it does not count against the property's overall density limits. The unit is meant only for guests or family occupying it on a non-fee basis and cannot be sold separately from the main house unless the county approves a lot split. The parcel must be at least one-half acre, though that minimum drops away if the lot is served by central water and sewer and the unit meets the zoning district's dimensional standards; the Florida Department of Health's requirements must be met in either case.
Only one accessory dwelling unit may serve a primary residence, and both the primary residence and the accessory unit must be conventional, site-built or modular construction; a mobile home or park model cannot serve as the guest house in any zoning district. Size is capped at no smaller than 375 square feet and no larger than 75 percent of the primary residence's enclosed square footage, with an absolute ceiling of 2,000 square feet of enclosed living space, keeping the accessory unit clearly subordinate to the main house.
Bedrooms are limited to two, with a special use permit from the zoning board of adjustment needed to add one more; under no circumstance can the unit reach four or more bedrooms.
Violations & Fines
Building or occupying an accessory dwelling unit that exceeds the size, bedroom or lot-size limits, or selling it apart from the main house without an approved lot split, is a zoning code violation enforceable through code enforcement and the special magistrate under chapter 2, with correction orders and civil penalties for noncompliance.
Frequently Asked Questions
Can I build a guest house on my agricultural lot in unincorporated Putnam County?
How big can an accessory dwelling unit be in Putnam County?
Can I sell my accessory dwelling unit separately from my house?
Sources & Official References
Other rules in Putnam County
How Putnam County compares: Easiest Cities to Build an ADU·Florida rules heatmap·Compare Putnam County to another location·View the Florida accessory structures overview
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