Marion County ADU Rules (2026)

Marion County’s Land Development Code regulates accessory dwelling units under §4.3.18, “Family/guest cottage/apartment” — a single combined provision covering both detached cottages and attached or internal apartments as one accessory non-commercial dwelling unit type. The use is permitted as accessory in residential and agricultural zones. Unlike most Central Florida counties, Marion’s ordinance does not set an explicit square-foot cap. The rule is relative: the accessory unit must be “an independent living unit smaller than the primary structure.”

In practice, Marion County Building Safety treats “subordinate” as meaning the accessory unit’s conditioned floor area cannot exceed the primary dwelling’s conditioned floor area. The typical approved unit is 600–1,000 sq ft. Homeowners designing anything larger — particularly on A-1 parcels where the primary dwelling may itself be several thousand square feet — should get the size interpretation in writing from Zoning before paying for architectural drawings. “Smaller than primary” is flexible on paper but can become rigid at plan review, and nobody wants to find out at permit stage.

Horse country and A-1 considerations

Marion County’s identity as Florida’s thoroughbred capital drives a lot of its zoning pattern. Large stretches of the county are zoned A-1 Agricultural with ten-acre minimums. On those parcels, the accessory unit envelope is generous — 35 ft height allowed, setbacks of 25 ft from front property line, and the “subordinate to primary” rule is rarely binding because the primary residence itself is usually substantial. A-1 is also where Marion County allows the most flexibility on use: a farm worker’s cottage and an accessory apartment are functionally similar under §4.3.18.

Inside R-1 residential subdivisions, the envelope tightens considerably. Height is capped at 20 ft, setbacks drop to 8 ft rear and 8 ft side, and the “subordinate to primary” test becomes more meaningful because the primary house is likely 1,800–2,500 sq ft. Homeowners in Silver Springs Shores, Marion Oaks, Rainbow Lakes, and the other large unincorporated subdivisions are looking at 600–900 sq ft accessory units as the realistic design target.

Ocala, Belleview, and Dunnellon

The three incorporated cities each have their own zoning codes that govern inside city limits. Ocala’s zoning code is structured differently from the county’s — it does not have a dedicated guest cottage or accessory apartment use type in the residential schedule, and applies a separate Form Based Code to the downtown core. Properties in designated historic areas require Historic Preservation Board design review, which adds 30 to 60 days to the permit timeline. Belleview and Dunnellon are smaller operations and generally align their accessory-structure rules with the county, but homeowners inside city limits should call the city directly rather than relying on county code summaries.

Income-limit context

Marion County sits alone in the Ocala Metropolitan Statistical Area under HUD’s Area Median Income schedule — it is not part of the Orlando-Kissimmee-Sanford MSA. The Ocala MSA’s 80-percent low-income threshold is meaningfully lower than Orlando’s, which matters if your ADU plan contemplates the Fla. Stat. § 163.31771 “affordable ADU” pathway. Marion County has not adopted a § 163.31771 ordinance as of the last verification date, so the affordability affidavit track is not operative in Marion today. See the Florida ADU law pillar (or in Spanish) for how the two tracks interact and why SB 48 did not change any of this in 2026.

Permit process

Marion County splits the process between two offices. Building Safety at 2710 E. Silver Springs Blvd. in Ocala runs the permit review and inspections — reach them at (352) 438-2400. Planning & Zoning at the same address handles the use determination and setback interpretation — (352) 438-2675. For a clean accessory-unit project, Zoning clears the use question first, then Building Safety issues the construction permit. Budget 8–12 weeks for the full cycle and $1,400–$2,800 in combined permit and impact fees for a 600–900 sq ft detached cottage. Impact fees apply; verify the current schedule against the Board of County Commissioners’ annual update.