Hillsborough County, FL ADU Rules & Size Limits

✓ From the county's published rules

Hillsborough County ADU rules at a glance

ADUs allowed?	Yes
Maximum ADU size	750 sq ft or 35% of the main home, whichever is less
Minimum lot size	7,000 sq ft
Owner must live on site?	Yes — in the main home or the ADU
Manufactured home as an ADU?	Often allowed, subject to the county's ADU and zoning rules

What the county rules say: “750 sq ft or 35% of primary home's living area, whichever is less (up to 1,200 sq ft or 25% by variance on lots >=14,520 sq ft)”

Allowed in single-family residential zones (incl. R-1) in unincorporated county. Owner must occupy either the primary home or the ADU. One ADU per lot. Applies to unincorporated county; Tampa, Temple Terrace, Plant City set their own rules.

On lots of 14,520 sq ft or more, a variance can allow up to 1,200 sq ft.

Source: Hillsborough County Land Development Code Sec. 6.11.02 (Municode); verified via county code Jul 2026.

Inside City Limits

Cities set their own rules

If the property is inside city limits, the city's ADU rules apply instead of the county's.

Tampa: 950 sq ft in ADU-eligible zones. Full rentable ADUs allowed only in designated neighborhoods/overlays (Seminole Heights, East Tampa, Tampa Heights, Lowry Park Central, Sulphur Springs, Temple Crest, Wellswood, Riverside Heights, and others - about 10 areas), max 950 sq ft. Everywhere else citywide only an 'Extended Family Residence' (EFR) is allowed - capped at 600 sq ft and restricted to family members. Owner must occupy either unit (Oct 2024 reform). Detached ADU cannot sit in front of the principal home; 50% impervious-surface cap; 1 off-street space; separate water/electric/gas meters required.

Before You Build

Confirm the rules first

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 Hillsborough County before you build.

Confirm with Hillsborough County: 813-272-5600 · 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

Hillsborough County ADUs, answered

Can I build an ADU in Hillsborough County, Florida?

Yes. Allowed in single-family residential zones (incl. R-1) in unincorporated county. Owner must occupy either the primary home or the ADU. One ADU per lot. Applies to unincorporated county; Tampa, Temple Terrace, Plant City set their own rules.

How big can an ADU be in Hillsborough County?

750 sq ft or 35% of the main home, whichever is less.

Does the owner have to live on the property?

Yes. Hillsborough County requires the owner to live on the property, in either the main home or the ADU.

Can a manufactured home be an ADU in Hillsborough County?

Often yes — many Florida counties allow a manufactured or modular home as an accessory dwelling unit, subject to Hillsborough County's ADU size, lot, and setback rules. Confirm with the county for your parcel.

ADU Rules in Hillsborough County, Florida

Hillsborough County ADU rules at a glance

Cities set their own rules

Confirm the rules first

Hillsborough County ADUs, answered

More ADU rules & homes

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