Home › ADU Rules by County › Alachua County
How big a backyard home (accessory dwelling unit) can be in Alachua County, who can build one, and who to call to confirm — from the county's published rules.
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| ADUs allowed? | Yes |
|---|---|
| Maximum ADU size | 1,700 sq ft or 50% of the main home, whichever is greater |
| Owner must live on site? | Not confirmed in our records |
| Manufactured home as an ADU? | Often allowed, subject to the county's ADU and zoning rules |
One ADU allowed as an accessory use in A, RE, RE-1, R-1aa, R-1a, R-1b and R-1c districts, and it does not count against residential density. Generous size cap. Zoning permit ($70) needs a site plan, floor plan and ADU affidavit; then a building permit for construction/placement. Gainesville city has its own rules.
Source: Alachua County Code Sec. 404.24; verified Jul 2026.
Inside City Limits
If the property is inside city limits, the city's ADU rules apply instead of the county's.
Before You Build
ADU rules are set by each county and city — Florida law (Fla. Stat. 163.31771) lets local governments allow ADUs but doesn't require it — and they can change, so always confirm the current rule with Alachua County before you build.
Confirm with Alachua County: 352-374-5249 · zoning department website ↗
Zoning is set locally and changes often. Answers are guidance only, not a permit guarantee. Always confirm with the local building/zoning department before purchase.
Common Questions
Yes. One ADU allowed as an accessory use in A, RE, RE-1, R-1aa, R-1a, R-1b and R-1c districts, and it does not count against residential density. Generous size cap. Zoning permit ($70) needs a site plan, floor plan and ADU affidavit; then a building permit for construction/placement. Gainesville city has its own rules.
1,700 sq ft or 50% of the main home, whichever is greater.
Our records don't confirm an owner-occupancy requirement for Alachua County — ask the county zoning department before you buy.
Often yes — many Florida counties allow a manufactured or modular home as an accessory dwelling unit, subject to Alachua County's ADU size, lot, and setback rules. Confirm with the county for your parcel.
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