Garage Conversion ADU in Villas - Design, Permits and Build Under One Contract

What a Garage Conversion ADU in Villas Really Looks Like - Cost, Timeline, and Scope

Converting your existing garage into a legal accessory dwelling unit in Villas runs $45,000 to $130,000 and takes 4 to 8 months, depending on how much of the original slab and walls you keep. Most of that range hinges on whether you need to dig up the floor for new plumbing, swap the old garage door for a code-compliant wall and impact windows, and bring a pre-2002 structure up to Lee County’s current hurricane code. Call us at (844) 638-7249 for a free on-site estimate, and we’ll walk the space with you before you commit to anything.

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We see a lot of Villas homeowners take this route when they need a true second living space but don’t want to lose yard on a small lot. The garage is already under roof and on a slab. The question is whether that slab and the walls around it can carry a dwelling unit without a full teardown. Derek Hollenbeck and our team have been answering that question across Lee County long enough to know that a garage conversion is rarely just drywall and a mini-split. It’s a full structural, electrical, plumbing, and envelope upgrade, and it gets done right the first time or it gets red-tagged. Our 730-Day Done Right Promise backs that.

How We Convert a Garage to a Legal ADU - Step by Step

Stage 1: Feasibility Walk and Survey (Days 1-3). Before we open a single wall, we pull the original building card from the county and measure what you actually have. In Villas, that means checking whether the existing slab has a proper vapor barrier underneath, whether the garage sits at or below the FEMA base flood elevation, and how much of the original CBS block has spalled from salt air. You’ll decide at this stage whether you want a studio layout or a one-bedroom with a separate bath and kitchenette, because that choice drives the plumbing scope and the permit path.

Stage 2: Demolition and Slab Openings (Days 4-10). The garage door comes out, and we cut the concrete floor where new drain lines need to stub up for a bathroom, kitchen sink, or laundry. If the slab has no existing underslab plumbing, this stage adds real cost and time, and it’s where a basic finish-out becomes a full conversion. We trench, run new PVC waste and vent lines, backfill with compacted stone, and pour the repair. Impact-rated window and door openings get framed and flashed to meet current Florida Building Code.

Stage 3: Rough-In: Electrical, Plumbing, HVAC, and Envelope (Days 11-25). New subpanel, dedicated circuits, LED layout, and any smart-home rough-in happen here. We add R-13 or better batts in all exterior walls and R-30 in the ceiling, then strap the roof-to-wall connection with approved hurricane ties if the original framing never had them. This is the point where a Villas job often uncovers corroded rebar or deteriorated mortar joints that need remediation before the county inspector will sign off on the rough-in.

Stage 4: Drywall, Trim, Flooring, and Fixtures (Days 26-40). Once the rough-in passes inspection, we close the walls with moisture-resistant drywall, install the interior doors and baseboards, and lay the finished floor you’ve chosen. Kitchenette cabinets and countertops go in, the bathroom gets its vanity and shower enclosure, and we set the water heater if the ADU has its own. The space starts looking like a home.

Stage 5: Final Inspections and Turnover (Days 41-50). The Lee County Building Department sends separate inspectors for building, electrical, plumbing, and mechanical. On a post-Ian rebuild or conversion in Villas, the final often includes a FEMA elevation certificate review if the property is in a mapped flood zone. We walk the unit with you, demonstrate every system, and hand you a written close-out packet with all permits signed off. The 730-Day Done Right Promise clock starts the day you take the keys.

The Finish and Layout Choices That Shape Your ADU

Every garage conversion we do in Villas ends up as one of two basic configurations, and the decisions below are the ones you’ll make at the contract table, not after demo starts. Here’s what you pick between, with the honest pros and cons of each:

• Studio vs. one-bedroom layout. A studio keeps the whole space open and puts the kitchenette and sleeping area in one room, with a separate bath. Lower cost, faster permit path. A one-bedroom ADU requires a framed interior partition, a closet, and an egress window in the bedroom, which adds square footage cost but gives you a real separate living quarters that rents or hosts family better.
• Kitchenette or full kitchen. A kitchenette with a small sink, under-counter fridge, and a two-burner cooktop keeps the plumbing scope tight. A full kitchen with a range, dishwasher, and vent hood adds a gas or 240V electric run and a mechanical exhaust path, pushing the job toward the higher end of the $45,000-$130,000 range.
• Mini-split HVAC vs. tying into the main house system. A ductless mini-split gives the ADU independent temperature control and costs less to run, plus it avoids opening the main house’s ductwork. Tying into the existing central system is possible on larger homes, but it often requires a zoning damper and a larger air handler, which gets expensive fast.
• Impact windows and doors vs. standard with shutters. In Lee County, any new opening in a dwelling unit must meet wind-borne debris protection. Impact-rated windows and a fiberglass entry door with laminated glass pass inspection without additional shutters and don’t require the homeowner to deploy panels before a storm. Standard windows with removable metal panels cost less up front but create an ongoing maintenance and preparation burden.
• Flooring: luxury vinyl plank vs. tile. LVP goes down fast over a properly leveled slab, handles moisture well, and costs less. Large-format porcelain tile looks permanent and keeps the floor cooler in a Florida summer, but it demands a dead-flat substrate and a higher material and labor budget.

What a Garage Conversion ADU Costs in Villas, FL

We price garage conversions in Villas between $45,000 and $130,000. That number is not a placeholder. It’s a real range driven by five variables we measure during the feasibility walk. A straightforward 300-square-foot garage that needs no structural repair, no underslab plumbing, and keeps the electrical panel where it is will sit at the lower end. A 500-square-foot two-car garage that needs a new subpanel, a bathroom with a full sewer tie-in cut through the slab, hurricane-strap retrofits, and impact-rated openings lands at the upper end. Here is what moves the line:

Slab condition and plumbing scope. If the original garage slab was poured without a vapor barrier, or if it has settled and cracked over 40 years of Villas’ high-water-table saturation, we’re cutting and replacing sections before we build on top. Adding a bathroom with a toilet, shower, and sink that tie into the existing main sewer line requires trenching through the slab, which alone can add $6,000-$12,000 to the job.

Electrical capacity. Older Villas homes often have a 100-amp service panel that’s already maxed out. Adding a small dwelling unit with its own water heater, mini-split, kitchen circuits, and lighting frequently triggers a panel upgrade to 200 amps, a service lateral replacement, and new grounding to current code. That’s a $3,500-$7,000 line item that doesn’t exist on newer homes with 200-amp service already in place.

Hurricane code compliance upgrades. Lee County will not close a permit on a pre-2002 CBS home without verifying that the roof-to-wall connection meets current high-wind standards. If the original trusses or rafters are toe-nailed without straps, we retrofit with approved connectors. The cost varies by roof geometry, but plan on $1,800-$4,500 if the original strapping is absent or inadequate.

Finish level. Builder-grade cabinets, a fiberglass shower pan, and standard LVP flooring keep the interior budget lean. Semi-custom cabinetry, a tiled walk-in shower with a glass enclosure, quartz countertops, and higher-end plumbing fixtures push the finish cost up by $8,000-$18,000. We use brand partners like KraftMaid for cabinets and Kohler for fixtures, so you’re choosing from a known catalog, not whatever was on sale at the supply house.

Permit and impact fee path. A garage conversion in unincorporated Lee County requires a building permit, and depending on scope, separate electrical, plumbing, and mechanical permits. If you’re converting unconditioned square footage into habitable living area, the county may assess impact fees and a school impact fee. We pull every permit, schedule every inspection, and give you a written, line-item estimate before the first shovel breaks ground. Our upfront pricing means the number you approve is the number you pay.

What’s included: the feasibility walk, engineered plans where required, all permits, demolition and disposal, slab cutting and plumbing trenching, electrical and panel work, framing, drywall, insulation, interior doors and trim, flooring, kitchenette or kitchen installation, bathroom installation, HVAC, impact-rated windows and entry door, final cleaning, and a full close-out walk with all sign-offs. What’s typically not included: furniture, appliances beyond the built-in cooktop and dishwasher, window treatments, and any upgrades you choose after the contract is signed. Call (844) 638-7249 for a free estimate built around your actual garage dimensions.

Why a Villas Garage Conversion Is Different From Any Other Market

The single biggest variable on a garage conversion in Villas is what the slab was built on and whether the walls above it are still sound. This community’s housing stock-CBS ranch homes from the 1960s through the mid-1980s-sits on flat, low-lying ground where the water table can be less than two feet below grade during the wet season. We regularly cut into a garage floor here and find no vapor barrier underneath, just forty years of moisture wicking up through the concrete. That means before we frame a single interior wall, we’re often pouring a new rat slab over a 10-mil vapor retarder just to meet current code for habitable space. On top of that, the salt air that drifts inland from the Caloosahatchee estuary has had decades to attack the rebar inside those CBS walls-we’ve opened up garages in Villas where the block face looked fine but the inside was spalling apart.

The post-Ian reality adds another layer. Any garage conversion that touches the roof framing or exterior envelope on a pre-2002 home triggers a mandatory review for hurricane-strap retrofits before Lee County will sign a final. Nearly every homeowner we work with in Villas initially underestimates the structural remediation scope because the garage “looks fine.” It usually isn’t. The good news is that once those upgrades are baked into the plan, the finished ADU meets the same wind-load standards as new construction, and that fact alone can lower your windstorm premium on the whole property. For homeowners who want to combine this project with other interior work, our Home Additions & ADU in Villas team often coordinates the ADU conversion alongside kitchen or bath updates in the main house, since the permit path already requires bringing systems up to code.

If you’re already opening walls and reworking floor plans, some Villas homeowners pair the ADU build with Cabinets & Countertops in Villas or Backsplash, Tile & Flooring in Villas to update the main home’s finishes while we’re on site. Our Home Additions & ADU crew handles the full scope under one contract, one permit set, and one warranty. And for the wider project context, everything we do across Villas comes with the same upfront pricing and the 730-Day Done Right Promise.

Frequently Asked - Garage Conversion ADU in Villas

Ready to Price Your Garage Conversion ADU in Villas?

The fastest way to get a real number is to have us walk the garage with you. We’ll check the slab, the walls, the panel, the roof framing, and the sewer path, then give you a written estimate that breaks down every line item. No pressure, no vague ranges, just a price you can take to the bank. Our phones ring to a live person, day or night-call (844) 638-7249 or reach out through our site, and we’ll put a free estimate on the calendar for your Villas property. Derek Hollenbeck and the whole crew stand behind the work for 730 days, in writing, so you’re not guessing whether it’ll hold up through the next hurricane season.

Written by Derek Hollenbeck, Owner at Groundwork Construction Co., serving Villas and Lee County with upfront pricing and a 730-Day Done Right Promise.