Garage Conversion ADU in Coral Gables - Same-Day Service, Done Right the First Time

What Does a Garage Conversion ADU Cost and Involve in Coral Gables?

A garage conversion ADU in Coral Gables typically runs $30,000-$80,000 and takes 8-14 weeks from permit approval to final inspection, depending on whether the existing structure needs structural reinforcement or utility relocation. The job transforms an attached or detached garage into a permitted living space with kitchenette, full bath, sleeping area, and independent climate control. Call (844) 665-0162 and we’ll walk your specific garage with you, same week.

Call (844) 665-0162

How We Convert a Garage to an ADU - Stage by Stage

Every garage conversion ADU in Coral Gables follows a fixed sequence, though the timeline stretches or compresses based on what we find once the drywall comes off. Here’s how we build it.

Stage 1: Structural assessment and as-built documentation (Days 1-3)

We measure every bearing point, photograph the existing slab for level and cracks, and map where the garage door header sits relative to your roofline. In Coral Gables, we’re often working with 1920s-1960s construction where the garage was never built to residential standards. The slab may be thin, the walls uninsulated, and the roof structure tied into the main house in ways that complicate fire separation. You’ll decide here whether to keep the existing footprint or push into the driveway for more square footage.

Stage 2: Design, Board of Architects, and permitting (Weeks 2-6)

We draft plans that satisfy Miami-Dade building code and Coral Gables’ separate Board of Architects review. This dual layer is non-negotiable in this city. The Board scrutinizes exterior finishes, roof pitch, window proportions, and color palette against the Mediterranean Revival code. We handle the submission, revisions, and hearings. You decide on exterior materials during this window - stucco texture, tile profile, paint color from the approved palette.

Stage 3: Demolition and rough construction (Weeks 7-10)

The garage door comes out, the opening gets framed and weather-sealed, and we address what the slab tells us. Many Coral Gables garages sit on original footings that have been compromised by decades of banyan root intrusion. If we hit displaced coral rock or cracked clay-tile sewer laterals, we coordinate arborist reports and install root barriers before pouring any new concrete. You’ll choose your window and door package here - impact-rated is mandatory in the HVHZ, and we source from Andersen, Pella, Marvin, or other approved lines.

Stage 4: MEP rough-in and insulation (Weeks 11-12)

Electrical panel capacity, plumbing extension from the main house, and mini-split HVAC placement all get finalized. We spray closed-cell foam for the thermal envelope and run dedicated circuits for the kitchenette and bath. If your main panel is original 1960s-era, you’ll decide whether to upgrade the whole service or add a subpanel.

Stage 5: Finishes, fixtures, and final inspection (Weeks 13-14)

Flooring, cabinetry, countertops, tile, and trim. We coordinate the final Board of Architects sign-off and Miami-Dade certificate of occupancy. You’ll do a walkthrough with our project lead before we hand over keys.

The Spec Choices That Shape Your Garage Conversion ADU

Every decision below moves your number and your daily experience. We lay out the honest trade-offs:

• Kitchenette scale: A wet bar with mini-fridge and microwave drawer runs $3,500-$6,000. A full two-burner cooktop, under-counter fridge, and single-bowl sink with cabinet surround pushes $8,000-$14,000. The smaller footprint suits rental ADUs where tenants don’t cook elaborate meals; the full kitchenette adds resale flexibility.
• Bath configuration: A 32-inch shower stall with basic fiberglass surround and a wall-hung vanity lands at $4,000-$7,000. A 36-inch tiled walk-in with niche, glass door, and quartz-topped vanity runs $9,000-$15,000. In Coral Gables’ humidity, the upgraded ventilation and moisture management of the tiled option pays back in mold prevention.
• Slab strategy: If the existing garage slab is 3.5 inches and cracked, we can overlay with self-leveling underlayment and call it done for $2,000-$4,000. If it’s heaved from root intrusion or below flood elevation, full removal and repour with proper vapor barrier runs $8,000-$15,000. The overlay saves money; the repour solves structural and insurance issues permanently.
• Exterior matching: Board of Architects compliance often requires custom stucco dash, barrel-tile roof extension, or arched window replication. Budget $4,000-$10,000 above standard finishes to meet code without visual compromise.
• Utility independence: Tying into existing electrical and plumbing saves $5,000-$10,000 versus separate meters and sewer connection. But separate utilities simplify rental accounting and avoid load conflicts with the main house.

What Garage Conversion ADU Costs in Coral Gables, FL

Garage conversion ADU projects in Coral Gables fall between $30,000 and $80,000. Here’s what pushes a job to either end:

A written estimate from us includes demolition, rough and finish carpentry, electrical and plumbing rough-in, insulation, drywall, flooring, fixtures, and paint. It does not include permit fees (typically $2,500-$5,000 in Coral Gables), separate utility connection fees if you choose them, or furniture and window treatments. Call (844) 665-0162 for an exact quote - estimates are free.

What Coral Gables Homes Specifically Do to This Job

Coral Gables isn’t Miami, and it isn’t unincorporated Dade. The city operates its own Board of Architects, a separate review body that scrutinizes virtually every exterior modification against George Merrick’s 1920s Mediterranean Revival vision. Barrel-tile roofs, stucco exteriors, arched openings, and specific color palettes aren’t suggestions here. They’re enforceable standards. This dual-approval layer - Board of Architects plus Miami-Dade permitting - routinely adds three to six weeks to what would be a faster process in Coconut Grove or South Miami.

The housing stock compounds this. We regularly work on 1920s-1960s homes with oolite limestone foundations and original coral rock walls that demand diamond-blade wet cutting and hydraulic lime mortars. Standard concrete-block repair techniques won’t bond properly and will fail within seasons. The same heritage-tree ordinance that preserves Coral Gables’ canopy means we’re often navigating massive banyan root systems that have cracked garage slabs and displaced original footings. Arborist coordination and root-barrier installation become line items, not afterthoughts.

Then there’s the HVHZ. Every window, every door, every roof-to-wall connection must meet the strictest wind-load code in the United States. Impact-rated glazing isn’t an upgrade; it’s the entry point. This raises material costs and restricts installer certification in ways that don’t apply thirty minutes north in Broward.

Homeowners here often pair the interior finish of a garage conversion ADU with Cabinets & Countertops in Coral Gables from our kitchen crew, or coordinate flooring continuity with Backsplash, Tile & Flooring in Coral Gables to match the main house. If you’re considering this as part of a full property expansion, see our broader Home Additions & ADU in Coral Gables scope. Our Home Additions & ADU hub covers prefab and stick-built options beyond garage conversions, and we serve Coral Gables from our Fort Lauderdale base with crews dedicated to this market.

Frequently Asked - Garage Conversion ADU in Coral Gables

Start With a Free On-Site Estimate in Coral Gables

We’ll walk your garage, check slab condition, roof structure, and utility access, then deliver a written estimate with real numbers - no pressure, no deposit required to review. Call (844) 665-0162 or request a visit online. Most Coral Gables homeowners hear back within one business day, and we schedule site visits within a week.

Written by Raymond Estevez, Owner at Groundwork Construction Co., serving Coral Gables since our South Florida founding.