Alachua County, FL Accessory Structures: ADU Rules (2026)

ULDC Section 404.24 governs accessory dwelling units in unincorporated Alachua County. ADUs are permitted as accessory to the principal residence in residential zoning districts A (Agricultural), RE, RE-1, R-1aa, R-1a, R-1b, and R-1c, in Rural/Agriculture, Rural Cluster, Estate Residential, Low Density, or Medium Density future land use designations. The ADU does not count toward gross residential density. Maximum heated/cooled living area is 1,700 sq ft or 50% of the principal residence gross square footage, whichever is greater. The ADU must meet the underlying zoning district setbacks and share the driveway with the principal residence. Water and sewer connections are required where utilities are available; otherwise, septic sharing is allowed subject to Florida Department of Health approval. The homestead exemption on the principal residence must be maintained. Applications are submitted electronically through the CitizenServe permitting portal with a $70 zoning permit fee, site plan, floor plan, and a signed Accessory Dwelling Unit affidavit. Building permits follow zoning approval. Cities within Alachua County (e.g., Gainesville, Alachua, Newberry, High Springs) administer their own ADU rules under their municipal codes.