Where we build ADUs on the First Coast

What are the ADU rules in the City of Jacksonville?

The City Council enacted Ordinance 2022-0448 on November 9, 2022, by a 12 to 7 vote, alongside a comprehensive plan amendment, Ordinance 2022-0447. As reported at the time, it made ADUs a permitted use in most low-density single-family neighborhoods. Key points, as of October 2026:

• One ADU per lot, built behind the main house and no taller than it.
• Footprint no more than 25% of the main home's gross floor area, or 750 sq ft, whichever is less.
• Owner on site: the homeowner must live on the property.
• HOAs: the ordinance does not override an association that prohibits ADUs.
• Not citywide: it does not apply to the Beaches or to Baldwin.

Read are ADUs allowed in Jacksonville for the details.

What else varies across Duval County?

• Flood zones. Lots along the St. Johns River, its creeks and the Intracoastal Waterway can sit in special flood hazard areas.
• Historic overlays. Neighborhoods such as Riverside-Avondale and Springfield have their own design standards.
• Septic. Parts of the county are still on septic systems, which limits where a new unit can go.

Jacksonville and Duval County are a consolidated government, so most addresses in the county fall under the city's code.