Miami's Accessory Structures: The Rules That Matter

Every city handles accessory structures a little differently. In Miami, Florida, there are 4 distinct rules that residents and property owners should be aware of. Some are stricter than what neighboring cities enforce, and others are more relaxed. Here is what you need to know.

Shed & Carport Rules

Miami classifies a carport as an Ancillary Building, so it must sit within the setback line for ancillary structures in your Transect Zone and needs a building permit before you build it.

Key details: Governing code: Miami 21 Zoning Code, Art. 1 & 5. Classification: Ancillary Building use, not accessory structure. Setback rule: Follows Ancillary Building setback line, not principal. Permit fine: $525 civil penalty, no permit (§ 2-829). Enclosure test: Must stay 20%+ open or it's a garage.

Building or enlarging a carport without a permit is cited under the city's Schedule of Civil Penalties (Code § 2-829): a flat $525 civil fine, separate from any Article 9/908.5-908.6 zoning correction order.

ADU Owner Occupancy

Miami requires an ancillary dwelling unit and the main house to stay under the same owner, and the ADU can only be rented while that owner holds a current homestead exemption on the property.

Key details: Ownership rule: Same owner for house and ADU. Rental condition: Current homestead exemption required. Governing zoning section: Miami 21 § 3.18. Enforcement/registration: City Code § 2-214. Renewal cycle: Annual, with homestead re-proof.

Losing homestead status while still renting the ADU, or a change of ownership without re-filing the disclosure statement, is grounds for the zoning administrator to deny or revoke the ADU registration certificate under City Code Section 2-214(g), on top of a Miami 21 zoning violation.

ADU Rental Restrictions

Renting a Miami ancillary dwelling unit requires a building permit, certificate of occupancy, and an annual ADU registration certificate, and the unit must remain predominately permanent housing: transient or temporary rentals are grounds for revocation.

Key details: Permit required: ADU registration certificate to rent. Owner status: Homestead exemption required. Use restriction: No transient or temporary lodging. Initial fee: $300 registration and inspection. Renewal: $250 annually with inspection.

Renting an unregistered ADU, losing homestead status while still renting, or using the ADU for transient or temporary lodging can mean registration denial or revocation, double fees, and enforcement under chapter 2, article X of the City Code.

This is one of the stricter rules in Miami's municipal code. If you are unsure whether your situation complies, it is worth checking with the city before proceeding.

ADU Rules

Miami allows one ancillary dwelling unit on single-family lots under Miami 21 Section 3.18, capped at two stories (one in T3-R) and no taller than the main house, plus mandatory city registration.

Key details: Where allowed: Single-family lots only. Max height: 2 stories (1 in T3-R). Detached 2-story separation: 10 feet minimum. Rental prerequisite: Homestead exemption required. Initial registration fee: $300.

Renting an unregistered ADU, or one that has lost its homestead-exemption backing, triggers denial or revocation of the ADU registration certificate and doubles the initial/annual registration fees under City Code Sec. 2-214(f)(3); violations also enforce through Chapter 2, Article X code-enforcement proceedings.

The Bottom Line

Miami's accessory structures rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Miami is broadly strict or permissive.

These rules come from Miami's publicly available municipal code. For complete penalty schedules, exemption details, and answers to common questions, see the individual ordinance pages throughout this guide.