ADU Permit Guide for Miami, Florida — Step-by-Step Process (2026)

Before you file any paperwork, you must verify four basic requirements. First, you need proof of property ownership through a current deed or title report dated within 30 days. The Miami Building Department will reject applications without this documentation.

Second, your property must contain an existing legal dwelling. This means a house or condo with a valid Certificate of Occupancy. Vacant lots don't qualify for ADU permits - you need a primary residence first.

Third, verify your property's zoning designation using Miami's online zoning map /search. ADUs are only permitted in T3-L (Low-Intensity Transect), T3-O (Open Transect), and T3-R (Restricted Transect) zones. Properties in T4, T5, or T6 zones follow different rules and may allow different types of secondary units.

Fourth, order a title report to identify any deed restrictions, easements, or HOA covenants that prohibit ADUs. Many Miami neighborhoods have HOA restrictions that supersede city zoning. The title company can complete this search within 3-5 business days for $200-$400.

Several factors will disqualify your property immediately. Properties in flood zones AE or VE require additional engineering review and may face height restrictions that make ADUs impractical. Historic district properties (like Coral Gables or parts of Coconut Grove) have design review requirements that add 6-8 weeks to the timeline.

Code violations on your existing home will halt the ADU permit process. The Building Department will search for open permits or violation notices before accepting your application. Clear any outstanding issues first - this typically takes 2-4 weeks depending on the violation type.

Maximum ADU size cannot exceed 50% of the primary dwelling's square footage or 1,200 square feet, whichever is smaller. For a 2,000-square-foot house, your ADU caps at 1,000 square feet. Measure your existing home's conditioned space using the same method the city uses: exterior walls to exterior walls, excluding garages and covered patios.

Start with Miami's zoning verification process through the Planning Department. Call 305-416-1454 to request a zoning verification letter, which costs $75 and takes 5-7 business days. This official letter confirms your property's zoning and any overlay districts that might affect ADU development.

Setback requirements vary by zone but generally require 5-foot side setbacks and 20-foot rear setbacks for detached ADUs. Attached ADUs follow the same setback rules as the primary dwelling. Use Miami's online setback calculator /tools/setback-calculator to determine exact measurements for your lot. Corner lots face additional front setback requirements on both street-facing sides.

Utility capacity assessment prevents expensive surprises later. Contact Miami-Dade Water and Sewer (305-665-7477) to verify your water meter can handle additional demand. Most residential meters accommodate one ADU, but older 3/4-inch meters may require upgrading to 1-inch service. Water meter upgrades cost $1,200-$2,500 and take 4-6 weeks to complete.

Electrical service capacity matters equally. Hire a licensed electrician to evaluate your main panel. Most ADUs require 40-60 additional amps. If your existing service is 100 amps or less, budget $2,000-$4,000 for electrical service upgrades through FPL.

Miami's Planning Department offers pre-application meetings every Tuesday and Thursday at 9:00 AM and 2:00 PM. Schedule these 48 hours in advance by calling 305-416-1454. Bring your property survey, preliminary ADU design sketches, and zoning verification letter. The planner will identify potential issues before you spend money on architectural drawings.

Tree preservation requirements affect many Miami properties. The city protects trees over 18-inch diameter and all native species over 12-inch diameter. If your proposed ADU location affects protected trees, you'll need an arborist report ($500-$800) and possible tree replacement fees ($150-$300 per removed tree).

Parking requirements add complexity to site planning. Miami requires one covered parking space per ADU, separate from primary dwelling parking. This space can be a garage, carport, or designated covered area. Uncovered parking doesn't satisfy this requirement.

Miami requires six specific drawing types for ADU permits: site plan, floor plan, electrical plan, plumbing plan, building elevations, and structural details. Your architect must stamp all drawings with a Florida license. Unlicensed designers cannot prepare ADU plans in Miami-Dade County.

The site plan shows your entire property with existing structures, proposed ADU location, setback measurements, parking areas, and landscaping. Include utility connections, stormwater management features, and any tree removal areas. The Planning Department rejects site plans missing setback dimensions or parking calculations.

Floor plans must show room layouts, door and window locations, emergency egress paths, and square footage calculations. Every ADU needs two forms of egress - typically a front door and bedroom window. Bedroom windows must be 24 inches wide minimum with sill heights below 44 inches.

Building elevations display exterior appearances from all four sides. Show roof lines, window and door styles, exterior materials, and height measurements. Miami's design guidelines require ADU architecture to complement the primary dwelling. Drastically different styles face planning review delays.

Structural engineering calculations are mandatory for all ADUs due to Florida's hurricane wind requirements. Your engineer must design for 180 mph wind loads (Wind Zone 4) and provide connection details for hurricane straps, anchor bolts, and roof attachments. Engineering costs range from $1,500-$3,500 depending on ADU complexity.

Energy compliance follows the 2020 Florida Building Code{:target="_blank"} energy provisions. Your architect must provide insulation specifications, window U-values, and HVAC sizing calculations. Florida doesn't follow California's Title 24 requirements - use IECC 2018 standards adapted for Florida's climate.

Pre-approved ADU plans aren't available in Miami. Every application requires custom architectural drawings. However, using similar approved plans from your neighborhood can reduce design time by 2-3 weeks since you'll know the design approach works.

Plan dimensions must include ceiling heights (8-foot minimum), room sizes, and total square footage calculations. Show all structural members for framing plans. The Building Department counts any space over 7 feet high toward total square footage, including loft areas and second floors.

Miami uses an online portal called "MyPermits" for all building permit applications. Access this system at miami.gov/building and create an account using your property owner information. The system doesn't accept applications from non-owners without notarized authorization letters.

Your application package requires eight specific documents: completed application form, architectural plans (6 sets), structural engineering calculations, site survey, utility capacity letters, contractor licenses, insurance certificates, and permit fees. Missing any document triggers automatic rejection.

Fill out Form BLD-001 (Residential Building Permit Application) completely. Common errors include incorrect property legal descriptions, missing contractor information, and unsigned owner declarations. The "scope of work" section must read "Construct new ADU" - generic descriptions cause processing delays.

Permit fees break down into three categories: plan review ($1,200-$2,400), building permit ($2,300-$7,600), and impact fees ($300-$800). Total costs range from $3,800-$10,800 depending on ADU size and complexity. The online system calculates exact fees after you input square footage and construction cost estimates.

Submit construction cost estimates at $175-$300 per square foot. Lower estimates trigger manual review and potential reassessment. Higher estimates increase permit fees proportionally. Use $225 per square foot as a safe middle ground for fee calculation purposes.

Upload all documents as PDF files under 10MB each. Large architectural plan sets may require splitting into multiple files. Name files clearly: "Site_Plan.pdf", "Floor_Plans.pdf", "Elevations.pdf". Unclear file names slow down reviewer assignment.

Pay fees online using credit cards or ACH bank transfers. The system doesn't accept cash, checks, or money orders. Keep payment confirmation emails - you'll need transaction numbers for status inquiries.

After submission, you'll receive an application number starting with "BLD". This number tracks your application through the review process. Write it down immediately - the system doesn't re-send confirmation emails.

Miami's Building Department assigns applications to review teams within 3-5 business days. Your ADU application goes through four separate reviews: zoning compliance, building code compliance, structural engineering, and fire safety. Each reviewer works independently and may request different corrections.

The initial review timeline runs 6-8 weeks for straightforward applications. Complex designs involving variances or unusual structural elements take 10-12 weeks. Hurricane season (June-November) adds 1-2 weeks to all timelines due to increased permit volume from storm repairs.

Plan check comments arrive via email as PDF documents. Each reviewing department sends separate comment letters. Zoning comments address setbacks, parking, and land use compliance. Building comments cover code issues like egress, ventilation, and accessibility. Structural comments focus on hurricane resistance and foundation design.

Typical first-round comments include missing structural connection details, incomplete egress calculations, and unclear utility routing. Fire department comments often request additional smoke detector locations and emergency access improvements. Address every comment specifically - general responses trigger resubmission requirements.

Hire your original architect to prepare correction drawings. Other architects need time to understand the design intent, adding 1-2 weeks to response time. Correction sets must highlight all changes with cloud bubbles and revision triangles. Unmarked changes confuse reviewers and extend the process.

Resubmit corrected plans through the same online portal using your original application number. Include written responses explaining how each comment was addressed. Reference specific drawing sheet numbers and detail callouts in your responses.

Second-round reviews take 3-4 weeks typically. Most ADU applications require 2-3 correction cycles before approval. Budget 12-16 weeks total for plan review completion. Expedited review services cost double the standard fees but reduce timelines by 30-40%.

Plan approval generates permit issuance authorization. You'll receive an email notification to pay final permit fees and schedule the pre-construction meeting. This meeting covers inspection scheduling, construction sequencing, and safety requirements.

Permit issuance allows construction to begin, but you must schedule the required inspections before starting each work phase. Miami requires nine mandatory inspections: foundation/footing, concrete slab, framing, plumbing rough-in, electrical rough-in, HVAC rough-in, insulation, drywall, and final inspection.

Schedule inspections through the MyPermits portal or by calling 305-416-1100. Request inspections by 2:00 PM for next-day scheduling. Friday requests get scheduled for Monday unless you specify weekend inspection needs (additional $150 fee).

Foundation inspection occurs after trenching but before concrete placement. The inspector verifies rebar placement, anchor bolt locations, and soil compaction. Hurricane tie-down systems require special attention - missing hurricane straps cause automatic failures.

Framing inspection happens after wall and roof framing completion but before insulation installation. Inspectors check structural connections, hurricane clips, window and door framing, and egress compliance. Have your structural plans available on-site during this inspection.

Rough-in inspections for plumbing, electrical, and HVAC occur after installation but before covering with drywall. Schedule all three rough-ins for the same day if possible. Inspectors verify code compliance, proper installation methods, and permit adherence. Failed rough-ins require re-inspection after corrections.

Insulation inspection verifies energy code compliance before drywall installation. Bring insulation certificates and energy compliance calculations. Missing vapor barriers or incorrect R-values trigger failures requiring material replacement.

Final inspection occurs after all construction completion including flooring, fixtures, appliances, and exterior work. The inspector checks overall workmanship, safety compliance, and permit adherence. Successful final inspection authorizes Certificate of Occupancy application.

Failed inspections require correction and re-inspection. Common failure points include missing smoke detectors, improper egress windows, and incomplete hurricane connections. Re-inspections cost $75 each and require 24-48 hour scheduling lead time.

Keep permit documents on-site during all inspections. Inspectors may reference approved plans and engineering calculations. Missing documentation can delay inspections even when work is correct.

Final inspection approval triggers the Certificate of Occupancy (CO) application process. Submit CO applications through the same MyPermits portal within 30 days of final inspection approval. Late applications require re-inspection and additional fees.

The CO application requires final utility connection confirmations from water, electric, and gas providers. Schedule utility finals before requesting the CO inspection. Most utilities need 48-72 hours notice for connection appointments.

Address assignment happens during CO processing for detached ADUs. Miami assigns addresses based on street access and emergency services requirements. Attached ADUs typically use the primary dwelling address with unit designations (A, B, etc.).

Certificate of Occupancy inspection verifies the completed ADU matches approved plans and meets all safety requirements. The inspector checks smoke and carbon monoxide detectors, emergency egress, utilities functionality, and overall safety compliance.

CO fees cost $150-$300 depending on ADU size and complexity. Processing takes 5-7 business days after successful inspection. You'll receive the official certificate via email and regular mail.

Legal rental occupancy begins only after CO issuance. Operating ADUs before certificate issuance violates Miami building codes and risks violation notices, fines, and forced vacancy orders.

Record the new ADU with Miami-Dade County Property Appraiser for tax assessment purposes. File Form DR-402 (Real Property Record Card Update) within 60 days of CO issuance. The county will reassess your property value including the new ADU square footage.

Utility account setup requires the Certificate of Occupancy number for separate metering. Contact Miami-Dade Water (305-665-7477) and FPL (305-442-8770) to establish independent utility accounts for rental management.

Setback violations cause 35% of ADU application rejections in Miami. Measure setbacks from property lines to the closest ADU wall, not from existing structures. Corner lots require setbacks from both street frontages. Use a licensed surveyor to verify measurements - homeowner measurements often prove inaccurate during review.

Incomplete structural engineering documentation delays 40% of applications by 4-6 weeks. Florida's hurricane requirements demand specific connection details, wind load calculations, and foundation designs. Generic structural plans from other states don't meet Miami-Dade requirements. Hire engineers experienced with Florida building codes.

Utility capacity issues affect 25% of applications, particularly in older Miami neighborhoods. Water pressure below 20 PSI or electrical service under 100 amps typically requires utility upgrades before ADU approval. Contact utility providers early - upgrade timelines extend 6-8 weeks during peak construction seasons.

HOA conflicts stop 20% of ADU projects completely. Homeowner association restrictions often prohibit rental units regardless of city zoning permissions. Review your HOA documents before spending money on plans. Some associations allow ADUs for family members but prohibit rental income.

Historical district restrictions add 6-10 weeks to applications in designated areas. Properties in Coral Gables, parts of Coconut Grove, and downtown Miami historic districts require design review board approval before building permit processing. Schedule design review meetings 4-6 weeks before permit submission.

Fire department access requirements delay applications when ADU locations block emergency vehicle access. Miami requires 20-foot wide access routes to all structures. Narrow driveways or side-yard ADU locations may not provide adequate emergency access. Consult with fire prevention officers during pre-application meetings.

Tree preservation violations trigger automatic rejections when protected trees are affected without proper permits. Miami protects specimen trees and native species regardless of size. Tree removal permits cost $150-$500 and require 3-4 weeks processing. Factor tree preservation into ADU site planning from the beginning.