Garage Conversion ADU in North Miami Beach: What It Costs and How Long It Takes
A garage conversion ADU turns your existing garage into a permitted living unit with its own kitchenette, bathroom, sleeping area, and separate entrance. In North Miami Beach, most garage conversion ADU projects run $30,000-$80,000 and take 8-14 weeks from permit approval to final inspection, depending on whether you’re converting an attached or detached structure and how much plumbing and electrical need to relocate. Call (844) 665-0162 and we’ll walk through your specific garage layout and give you a free, itemized estimate.
How We Convert a Garage into an ADU, Step by Step
Every garage conversion ADU in North Miami Beach follows a five-stage sequence. We’ve refined this over dozens of conversions across Miami-Dade’s High Velocity Hurricane Zone, where Miami-Dade NOA-compliant materials and HVHZ structural detailing aren’t optional extras, they’re code-mandated checkpoints that can add days to inspections if handled wrong.
Stage 1: Site evaluation and feasibility (3-5 days). We measure your garage’s existing footprint, check ceiling height against Miami-Dade’s minimum habitable space requirements, and identify what’s staying versus what moves. You’ll decide here whether you want a full kitchen or a kitchenette, whether the bathroom can tap into existing sewer lines or needs a pump system, and whether you’re keeping the garage door opening as a glazed entry or framing it in permanently. We photograph every structural connection and flag any concrete spalling or rebar corrosion, common in 1960s-1970s CBS homes in the inland pockets of 33160.
Stage 2: Design, drafting, and permit submission (4-6 weeks). Our drafting team produces architectural plans, MEP layouts, and structural details for Miami-Dade Building Department review. You’ll choose your material grades and fixture lines during this window, not after permits issue, because product substitutions mid-build trigger re-review. We specify impact-rated windows and doors from our Andersen, Pella, or CGI lines, HVHZ-compliant roofing ties if we’re modifying the envelope, and moisture-barrier systems rated for salt-air exposure.
Stage 3: Demolition and rough construction (2-3 weeks). We strip the garage to structure, raise the floor if there’s a step-down from the main house, frame interior partitions, and run new plumbing, electrical, and HVAC. This is when we discover whether your slab can handle the load of a tiled bathroom or if we need to reinforce, a reality check that separates experienced North Miami Beach contractors from out-of-town speculators.
Stage 4: Systems, insulation, and envelope (2-3 weeks). We install Miami-Dade NOA-approved insulation, hang and finish drywall, set tile or flooring, and run final electrical and plumbing connections. You’ll do a walkthrough to confirm outlet placement, lighting zones, and cabinet layout before we close walls. Our Home Additions & ADU crew coordinates directly with our interior trades, so your Cabinets & Countertops in North Miami Beach selections arrive templated and ready, not back-ordered from a third party.
Stage 5: Finish work, inspection, and certificate of occupancy (1-2 weeks). Final paint, fixture installation, appliance hookups, and Miami-Dade’s series of inspections: rough, plumbing, electrical, mechanical, and final. We don’t call you for the last payment until the C.O. is in hand. Most garage conversion ADU projects in North Miami Beach clear in a single inspection cycle because we front-load the compliance documentation.
The Spec Choices That Shape Your Garage Conversion ADU
Every decision below moves your final number and how the space lives. We don’t default you to “good enough” and hope you don’t ask questions.
- Floor system: raised wood frame versus slab-on-grade with moisture barrier. A raised floor gives you plumbing chase space and thermal separation from a cool concrete slab, but costs $3,000-$6,000 more and eats ceiling height. Slab-retain with a vapor barrier and insulated subfloor is cheaper and preserves headroom, but you’re walking on concrete. In North Miami Beach’s humidity, we typically spec raised floors for detached garages and slab solutions for attached conversions where the main house HVAC can help condition the mass.
- Kitchenette versus full kitchen. A kitchenette with a two-burner cooktop, under-counter fridge, and single-bowl sink runs $4,000-$8,000 installed. A full kitchen with range, dishwasher, full-size refrigerator, and custom cabinetry from KraftMaid or Wellborn pushes $12,000-$22,000. For rental ADUs, the full kitchen commands higher rent. For in-law use, the kitchenette often suffices.
- Bathroom scope: wet bath versus full bath with separate shower. A wet bath, where the toilet and shower share a fully waterproofed space, fits in 25 square feet and costs $5,000-$9,000. A full bath with a tiled shower, vanity, and water closet needs 40+ square feet and runs $9,000-$16,000. Kohler and Moen fixtures sit at different price tiers within that range.
- Entry configuration: converted garage door versus new framed opening. Keeping the garage door opening and installing a glazed wall system with an impact-rated door saves framing labor but limits insulation and security. Framing it in with CBS or reinforced stud wall gives better thermal and acoustic performance, adds $2,500-$5,000, and reads more like residential architecture than a converted garage.
- HVAC: mini-split versus tying into existing central system. A dedicated mini-split with its own condenser runs $3,500-$6,500 and gives the ADU independent climate control. Extending ductwork from your main house system is cheaper upfront but can overload a unit not sized for the additional load, and it violates ADU independence requirements in some Miami-Dade jurisdictions.
What Garage Conversion ADU Costs in North Miami Beach, FL
Garage conversion ADU projects in North Miami Beach typically fall between $30,000 and $80,000. Here’s what pushes a job toward the low or high end of that range.
| Cost Driver | Low-End Impact | High-End Impact |
|---|---|---|
| Garage size and existing condition | 400 sq. ft., sound CBS structure, no spalling | 600+ sq. ft., concrete repair needed, rebar corrosion |
| Plumbing relocation distance | Bathroom backs up to main house wet wall | New sewer ejector pump, 30+ feet of trenching |
| Electrical service capacity | 200-amp panel with spare capacity | Service upgrade to 320-amp, new meter base |
| Material and fixture grade | Stock cabinetry, standard tile, mini-split | Custom cabinetry, Silestone or Caesarstone counters, premium fixtures |
| Permit scope and HOA coordination | Single-family home, no HOA | Condo or townhome, board approval, milestone inspection documentation |
Our written estimates itemize labor, materials, permits, and a line for anticipated but unexposed conditions, typically 5-8% of construction cost. What’s not included: your HOA application fees, temporary relocation if you’re living in the space during construction, or landscaping repair from any exterior trenching. We discuss every line before you sign, not after we start demolition.
What North Miami Beach Homes Specifically Do to This Job
North Miami Beach’s housing stock splits sharply between two worlds, and your garage conversion ADU lives in one of them.
The inland pockets of 33160, roughly west of Biscayne Boulevard, hold mid-century CBS single-family homes from the 1950s through 1970s. These are the garages we convert most often: attached two-car structures on slabs, originally built with minimal insulation and single-pane jalousie windows, now needing full envelope upgrades to meet current Miami-Dade energy code. The concrete block is usually sound, but the roof-to-wall connections predate modern hurricane strapping, so we frequently add structural ties as part of the permit package, not as a surprise change order.
The condo and townhome stock along the Intracoastal and near the Atlantic is a different challenge. These buildings, many poured-concrete high-rises from the 1960s-1980s, are now swept up in Florida’s post-Surfside Milestone Inspection Law with its tightened 25-year coastal threshold. If you’re a unit owner hoping to convert a ground-floor storage garage or parking bay into an ADU, you’re not just dealing with Miami-Dade permitting, you’re navigating a condo board that’s simultaneously managing structural recertification, concrete spalling repairs, and rebar remediation. We coordinate our scope with the building’s engineer of record and document every product with its Miami-Dade NOA, because the board’s recertification contractor and our ADU conversion are sharing the same inspection timeline. Contractors who can’t speak that language don’t get past the application stage in these buildings.
The salt air and year-round humidity mean moisture management isn’t a finishing detail, it’s a survival strategy. We specify cement-board backing behind all wet-area tile, closed-cell spray foam or rigid foam insulation with taped seams, and mechanical ventilation in every bathroom and kitchenette. Skip any of these and you’re looking at mold remediation in three to five years, guaranteed.
Serving North Miami Beach, FL - Our Local Coverage Area
We’re based in the North Miami Beach area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
Frequently Asked - Garage Conversion ADU in North Miami Beach
Most garage conversion ADU projects in North Miami Beach take 12-20 weeks total: 4-6 weeks for design and permitting, 8-14 weeks for construction. Condo and townhome projects add 2-4 weeks for HOA and building management coordination. Call (844) 665-0162 and we’ll give you a realistic timeline based on your specific property type.
Yes, absolutely. Miami-Dade Building Department requires full permits for any garage conversion ADU, including architectural, structural, plumbing, electrical, and mechanical approvals. If your property is in a condo or townhome, you’ll also need HOA board approval and possibly a modification to the building’s certificate of occupancy. We handle the entire permit package as part of our standard process.
Sometimes, but only if your garage already sits near a wet wall with drain capacity. Most North Miami Beach garage conversion ADU projects need at least a toilet and sink, which means running new drain lines. If your slab doesn’t have the fall for gravity drainage, we install a sewage ejector pump system, adding roughly $2,500-$4,500 to the project.
Yes, typically by 40-60%. A garage conversion ADU in North Miami Beach starts around $30,000 because you’re working within an existing structure with roof, walls, and foundation already in place. New detached ADU construction in this market runs $90,000-$220,000 for comparable square footage. The trade-off is layout constraints: you’re adapting someone else’s garage footprint, not designing from scratch.
We warranty our workmanship for one year from certificate of occupancy, with manufacturer warranties on all materials and fixtures, typically 10 years to lifetime depending on the product line. Our Silestone and Caesarstone countertops carry 25-year residential warranties; Kohler and Moen fixtures carry limited lifetime coverage. We register every warranty in your name, not ours, so you’re covered even if you sell.
Ready to Convert Your Garage? Let’s Talk Through the Specifics
Every garage in North Miami Beach is different, and the only way to price your garage conversion ADU accurately is to see it. Call (844) 665-0162 to schedule a free on-site evaluation. We’ll measure your space, check your existing systems, flag any structural or HOA considerations, and email you a detailed, itemized estimate within 48 hours. No deposit required to start the conversation. Our Home Additions & ADU in North Miami Beach team covers every corner of North Miami Beach, and many homeowners pair their ADU conversion with updated Backsplash, Tile & Flooring in North Miami Beach in the main house for a cohesive finish.
Written by Raymond Estevez, Owner at Groundwork Construction Co., serving North Miami Beach and South Florida.