Fast, Reliable Home Additions & ADU Across Miami
Home additions and ADU construction in Miami typically run $53,100-$153,400 for room or second-story expansions, $35,400-$94,400 for garage conversions, and $106,200-$259,600 for new detached units, with most projects taking 4-8 months from permit to completion. We’re Miami’s full-scope residential construction partner, and our crew makes the drive down from Fort Lauderdale regularly to handle everything from NOA-compliant permitting to final inspection on homes from Little Havana to Coconut Grove. If you’re weighing whether to move or expand, call (844) 665-0162. We’ll walk your property and give you a real number, not a guess.
Why Groundwork Construction Co. of South Florida Is Miami’s Preferred Home Additions & ADU Company
We’ve been working in Miami long enough to know that a contractor who builds in Broward but “services” Miami is asking for trouble. Miami-Dade County’s Notice of Acceptance system means your windows, doors, roofing assemblies, and even structural fasteners need county-specific approval that doesn’t transfer from one county to the next. We’ve seen out-of-county crews order entire material packages only to fail inspection because the products carried Broward approvals.
Our Home Additions & ADU team handles the NOA verification before we ever pull a permit. That discipline saves Miami homeowners weeks of delay and thousands in reorder costs.
We typically respond to Miami inquiries within a few hours, and we schedule site visits across the 33155, 33156, 33101, and 33122 ZIP codes weekly. Homeowners in Coral Gables and Coconut Grove know our trucks because we’ve done multiple projects on the same blocks, building additions onto the 1940s-1970s CBS homes that dominate central Miami’s housing stock.
Raymond Estevez built Groundwork Construction Co. on the principle that homeowners deserve one accountable contractor and genuine material choice. In Miami, that means you pick from our 50+ brand partners - KraftMaid or Wellborn for cabinetry, Cambria for countertops, James Hardie for exterior siding - and we verify every product’s Miami-Dade NOA status before it hits your job site.
Our Home Additions & ADU Services in Miami
ADU Design & Permitting
Every Miami ADU starts with a reality check on what Miami-Dade will actually approve. The county’s NOA system adds a layer most Florida jurisdictions don’t have, and we build that compliance step into our design phase rather than discovering it at inspection. For a recent project near Flagami, we spent three weeks upfront confirming NOA listings for impact-rated windows and epoxy-coated fasteners before submitting plans. That front-loaded effort meant permit approval in six weeks instead of the four-month horror stories we hear from homeowners who started with less thorough crews.
Garage Conversion ADU
Garage Conversion ADU - Miami projects are the fastest path to rental income or multigenerational space, but they come with specific headaches on older homes. Most central Miami garages sit on slabs poured decades ago, with original jalousie windows and rebar that’s been drinking salt air since the Eisenhower administration. In Flagami (33126), we converted a 1952 CBS garage into a one-bedroom ADU. Behind the original jalousie windows and corroded rebar, we found a single-panel door with a 1960s “Magic Eye” opener - past its life. We swapped the door for a Miami-Dade NOA-approved impact model (no parts available for the old one) and reinforced the block walls, using epoxy-coated rebar to handle the salt-air exposure. The project came in at $47,000, right in our typical garage conversion range.
New Detached ADU
Our New Detached ADU service in Miami gives homeowners the most flexibility for rental income or family space, but it’s also where Miami’s geography fights back hardest. The porous Miami Limestone and shallow water table - sometimes just 2 feet down - make conventional foundation work risky. We’ve watched contractors trench for footings without accounting for hydrostatic pressure, then see slabs crack during the next king tide when water pushes up through the substrate instead of just arriving from above. Our ground-level pours include vapor barriers and drainage strategies designed for Miami’s upside-down water behavior. We also partner with prefab innovators including Abodu, Dvele, Mighty Buildings, and Boxabl for homeowners who want faster, factory-controlled builds with Miami-Dade NOA documentation already in hand.
Junior ADU & Interior Conversion
Our Junior ADU & Interior Conversion service in Miami works well in denser neighborhoods where setback rules make detached units impossible. Converting part of an existing home into a separate living unit means navigating Miami’s parking requirements, utility separations, and - again - NOA-compliant materials for any new exterior openings. In Little Havana’s 33125 ZIP, we converted a 1,200-square-foot home’s rear wing into a junior ADU with its own kitchenette and exterior entrance. The original 1950s aluminum windows had to go; we installed PGT impact-rated units with verified NOA listings, and we ran separate electrical meters per Miami-Dade requirements. The homeowner now collects $1,850 monthly in a market where comparable apartments rent for $2,200-plus.
What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Miami
We don’t believe in “contractor’s choice” material lock-ins. Our 50+ brand partnerships mean you select products that match your budget and taste, and we verify Miami-Dade compliance before ordering. For cabinetry, that might mean KraftMaid’s semi-custom lines or Wellborn’s full-custom options. Countertops run from Cambria’s domestic quartz to Silestone’s international palette. Exterior siding includes James Hardie’s fiber-cement systems, all of which we confirm carry current NOA approval for hurricane-zone installation. We maintain relationships with Miami-area suppliers who stock NOA-documented inventory, which means faster turnaround when a project needs materials now, not after an eight-week special order.
Common Home Additions & ADU Problems We See in Miami Homes
- NOA failures from out-of-county sourcing. Installers order doors and windows from Broward stock that lack Miami-Dade NOA approval, leading to failed inspections and costly reorders. We verify every product’s NOA listing before it ships.
- Foundation damage from ignored water tables. Contractors trench foundations without accounting for the 2-foot water table, then watch hydrostatic pressure crack the slab of the new ADU during a king tide. Our ground-level work plans for water pushing up, not just pooling on top.
- Salt-air rebar corrosion in structural connections. Rebar and fasteners not rated for Miami’s salt air corrode within years, compromising the structural integrity of an addition unless stainless or epoxy-coated steel is used. We specify corrosion-resistant hardware on every Miami job.
- Legacy garage door and opener obsolescence. Original single-panel doors and 1960s-1970s openers have zero parts availability. We assess whether retrofit is possible and, when it’s not, specify NOA-approved replacements that pass inspection and survive the next hurricane season.
Pricing for Home Additions & ADU in Miami, FL
These are real ranges for Miami’s market, calibrated for the NOA compliance, labor, and material sourcing realities of building in Miami-Dade County:
| Service | Typical Range in Miami |
|---|---|
| Garage Conversion ADU | $35,400-$94,400 |
| ADU Construction (new detached) | $106,200-$259,600 |
| Home Addition (room or second story) | $53,100-$153,400 |
What moves you within these ranges? Finish selections drive the biggest swings - a Cambria countertop versus a basic laminate, KraftMaid full-overlay cabinets versus stock boxes, impact-rated PGT windows versus standard vinyl. Site conditions matter too: if we’re cutting into 1950s CBS with actively corroding rebar, structural remediation adds scope. We don’t guess at your number. Call (844) 665-0162 for a free estimate with line-item pricing.
We Also Serve Cities Near Miami
Our crews work throughout the core Miami area and surrounding neighborhoods including Miami proper, Allapattah, Brownsville, Coconut Grove, and Coral Gables. Whether you’re in a 1940s CBS bungalow near Coral Way or a 1960s ranch in Coconut Grove’s leafy streets, we understand the local housing stock and permitting path.
Serving Miami, FL - Our Local Coverage Area
We’re based in the Miami area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs - Home Additions & ADU in Miami
Yes. Every window, door, and structural fastener in a Miami-Dade addition or ADU must carry a current Notice of Acceptance from the county, separate from Florida’s statewide building code. We verify NOA listings before ordering any product for your job. Call (844) 665-0162 and we’ll check your specifications against the current database.
Miami’s water table sits as shallow as 2 feet in many areas, and water rises through the porous Miami Limestone during heavy rain and king tides, creating hydrostatic pressure from below. Conventional below-grade waterproofing fails here; our ground-level slabs include vapor barriers and drainage systems designed for upward water migration. Basements are generally impractical in Miami without extensive and expensive dewatering systems.
Standard uncoated rebar will corrode within years in Miami’s salt-air environment, and standard lumber framing requires careful moisture management in our humidity. We specify epoxy-coated or stainless steel rebar and pressure-treated or engineered lumber rated for South Florida’s conditions. These material upgrades are non-negotiable for structural longevity and code compliance.
A garage conversion ADU in Little Havana typically takes 14-20 weeks from permit submission to final inspection, assuming no major structural surprises. The 1950s-1970s CBS homes in 33125 often reveal corroded rebar or failing original windows once work begins, which can add 2-4 weeks for remediation and NOA-compliant replacement sourcing. We build contingency into every timeline we quote.
Yes. Flagami follows Miami’s zoning code, which generally limits detached ADUs to one story and caps height at 15-18 feet depending on specific lot conditions and proximity to primary structures. Setback rules also apply. We verify zoning constraints during our initial site assessment before committing to any design direction. Call (844) 665-0162 to schedule that assessment.
Written by Raymond Estevez, Owner at Groundwork Construction Co., serving Miami since our founding. One contractor, every phase. You choose the brand, we handle the build. Call (844) 665-0162 for your free estimate.