ADU Rules in Miami, FL (2026)
ADU rules, permit requirements, size limits, and fees for Miami, FL. Source-cited from official municipal code.
Whether ADUs are allowed in Miami, FL has not been confirmed — see the official source before proceeding.
Whether Miami, FL permits accessory dwelling units (ADUs) has not been confirmed from an official source. ADUs — also called granny flats, in-law units, or secondary suites — are secondary housing units on a single-family or multifamily lot. Contact the local building department through their official website to verify current ADU rules before proceeding, as regulations may have changed since this data was last reviewed.
ADU Size Limits
ADU Size Limits in Miami: Detached ADU: size varies by zoning — see official source (max height: varies — see official source). Attached ADU: size varies by zoning — see official source.
| Type | Max Size | Max Height |
|---|---|---|
| Detached ADU | See official source | See official source |
| Attached ADU | See official source | See official source |
Permit Fees
ADU Permit Fees in Miami: Plan check fee: Varies. Building permit fee: Varies. Impact fees: None. School fees: None or N/A. Total estimated permit cost: Varies.
| Fee Type | Amount |
|---|---|
| Plan Check | $500–$2,500 |
| Building Permit | Based on construction value — typically $1,500–$5,000 |
| Impact Fees | Capped at single-family rate per Florida HB 1339 (2024) — previously $5,000–$15,000; now reduced |
| School Fees | Miami-Dade County school impact fee applies — approximately $3,000–$5,000 for residential units |
| Total Estimate | See official source |
Permit Timeline
Miami ADU Permit Timeline: Permit timeline has not been confirmed — contact the department for current processing times. Apply through the local building department online permit portal. Contact them through their official website for current contact information.
Setback Requirements
ADU Setback Requirements in Miami: Front setback: follows zone standard. Side setback: no minimum. Rear setback: no minimum.
Parking Requirements
Parking Requirements: Parking requirements have not been confirmed — see official source.
Restrictions & Requirements
- ADU must comply with Miami 21 Transect Zone standards for the property
- Carriage House (detached ADU) in T3 zones must be accessed from rear lane or alley when available
- ADU cannot be sold separately from primary lot under standard subdivision rules
- Short-term rental of ADU requires compliance with Miami-Dade STR regulations
- Historic districts (e.g., Coconut Grove, Little Havana) may require additional design review
- ADU must have permanent foundation — no recreational vehicles or mobile homes
How Many ADUs Are Allowed?
Number of ADUs Allowed in Miami: Single-family lots: not confirmed — see official source. Multifamily properties: not confirmed — see official source.
- Single-Family Lots
- 1 ADU (Carriage House) per T3 lot; additional units may be permitted under T4+ zoning
- Multifamily Properties
- Varies by Transect Zone — T4 and above permit multiple dwelling units by right
Statewide Preemption
ADU Preemption
We could not confirm a statewide ADU preemption statute for Florida.
View Florida preemption detailsFrequently Asked Questions
Can I build an ADU in Miami?
Yes. Miami, FL allows accessory dwelling units. On a single-family lot you can build 1 ADU (Carriage House) per T3 lot; additional units may be permitted under T4+ zoning.
How big can an ADU be in Miami?
The maximum size for a detached ADU in Miami is 750 sqft or 50% of primary structure, whichever is less square feet.
How long does it take to get an ADU permit in Miami?
The typical ADU permit timeline in Miami is Ministerial approval required per Florida HB 1339 — no discretionary review for ADUs meeting objective standards. Miami Building Department typically processes ADU permits in 4-8 weeks for plan check. Construction typically 4-12 months.. Total estimated permit fees are $5,000–$15,000 total permit fees depending on size and scope.
Do I need extra parking for an ADU in Miami?
Miami parking rules for ADUs: No additional parking required for ADUs near transit per Florida HB 1339 (2024). Miami-Dade Transit's Metrorail and Metromover provide extensive transit access in urban areas. ADUs in T3 zones typically require 1 space unless within one-half mile of a transit stop per state law.
Do I have to live on-site to have an ADU in Miami?
Owner-occupancy requirement in Miami: Owner-occupancy requirement eliminated statewide effective July 1, 2024 per Florida HB 1339. Neither primary dwelling nor ADU must be owner-occupied.
Source: Miami 21 Zoning Code (Ordinance 13114, as amended); Florida Statutes 166.0451 (HB 1339, 2024). Last verified April 5, 2026. View source