Miami ADU permit requirements
Last reviewed: June 22, 2026
Quick answer
Permitting an accessory dwelling unit (ADU) in Miami, Florida means pulling a building permit from the local authority that issues it. ArchPermit tracks 15 source-cited requirements (8 required, the rest conditional) for this jurisdiction. Submittals go through iBuild + ePlan / ProjectDox. These requirements were last reviewed June 22, 2026; confirm the exact forms and fees with the local permitting authority.
A source-cited checklist of what an ADU (accessory dwelling unit) permit package needs in City of Miami. Every item links to its authoritative source; items that vary are flagged to confirm locally.
The City of Miami publishes no ADU-specific submittal checklist — what other cities call an ADU is an 'Ancillary Unit' under the Miami 21 zoning code, built as a standard new residential structure under a normal building permit (iBuild + ProjectDox). Ancillary units are permitted by-right in T3-L and T4 zones (not T3-R/T3-O under the adopted code), max 450 sf, single-family use, rentable only if the principal-dwelling owner resides on site, with one parking space. Miami is entirely within the Florida Building Code High-Velocity Hurricane Zone (HVHZ). NOTE: most 'Miami ADU' information online is Miami-Dade COUNTY — a separate jurisdiction whose rules do not apply within city limits. Confirm the exact submittal set with the Building Department.
- Ancillary-Unit Parking Spacerequired
Minimum one parking space per ancillary dwelling unit (T3/T4 per Miami 21 use regulations).
source · reviewed 2026-06-22 - Ancillary-Unit Size Compliance (≤450 sf)requiredverify locally
Documentation that the unit is ≤450 sf (excluding garage) per Miami 21 T3 supplemental regulations. Confirm the current figure on live Municode.
source · reviewed 2026-06-22 - Architectural Plan Sheetsrequiredverify locally
Floor plans, elevations, and sections for the new ancillary structure. Standard for any new-structure permit; not enumerated on an ADU-specific City page.
source · reviewed 2026-06-22 - Boundary / Property Surveyrequiredverify locally
Current survey showing the lot, existing principal building, and proposed unit location for zoning setback/placement review. Standard new-structure item; not on a City ADU-specific page.
source · reviewed 2026-06-22 - Signed & Sealed Construction Plans (PDF)required
Plans signed and sealed by a Florida-registered architect/engineer, uploaded as PDF to ProjectDox per the City's file-naming standards.
source · reviewed 2026-06-22 - Site Plan (Miami 21 zoning compliance)requiredverify locally
Site plan demonstrating Miami 21 compliance — setbacks, lot coverage, placement, and the required ancillary-unit parking space.
source · reviewed 2026-06-22 - Structural Plans / Calculations (HVHZ wind)requiredverify locally
Structural drawings and wind-load calcs meeting Florida Building Code HVHZ requirements. Inferred from Miami's HVHZ status; no City ADU page states it explicitly.
source · reviewed 2026-06-22 - iBuild Permit Applicationrequired
New building-permit application started electronically in the iBuild portal; all new applications must begin here.
source · reviewed 2026-06-22 - Electrical Sub-Permitconditional
Separate electrical sub-permit for the new unit's wiring.
source · reviewed 2026-06-22 - Historic Certificate of Appropriatenessconditional
If the property is in a historic district, a Certificate of Appropriateness applies before/with the building permit.
source · reviewed 2026-06-22 - Mechanical (HVAC) Sub-Permitconditional
Separate mechanical sub-permit for HVAC.
source · reviewed 2026-06-22 - Owner-Occupancy / Single-Family-Use Complianceconditionalverify locally
Showing the unit is a single-family-residence dwelling, rentable only with the owner on site. A code condition; the City has not published a specific affidavit form.
source · reviewed 2026-06-22 - Plumbing Sub-Permitconditional
Separate plumbing sub-permit (an ancillary unit requires a kitchen sink and bathroom).
source · reviewed 2026-06-22 - Product Approvals / Notice of Acceptance (NOA)conditional
Miami-Dade NOA or FL Product Approval for windows, doors, roofing, and other regulated assemblies (HVHZ). Required where such products are used.
source · reviewed 2026-06-22 - Tree Permit / Dispositionconditional
Required if construction affects protected trees on the lot or right-of-way.
source · reviewed 2026-06-22