What a Garage Conversion ADU in Lely Actually Costs and How Long It Takes
A garage conversion ADU in Lely turns your existing garage into a self-contained living unit with its own entrance, kitchen, bathroom, and sleeping area. Most projects in this community cost between $45,000 and $130,000, with the majority landing around $70,000 for a well-finished studio or one-bedroom space that meets Lely Resort’s architectural standards. The work typically takes 12-16 weeks from permit submission to final inspection by Collier County. Call us at (844) 638-7249 to get a written line-item estimate for your specific garage.
We see three problems repeat across Lely conversions: the garage slab wasn’t poured to residential floor elevation and needs to be raised, the existing roof structure struggles to carry new HVAC and insulation loads under current code, and homeowners don’t budget for the mandatory Architectural Review Committee approval that precedes every building permit here. We plan for all three from day one.
How we convert a garage to an ADU in Lely, stage by stage
Most builders start with a sledgehammer. We start with a site survey and the ARC application, because without committee sign-off from Lely Resort, Collier County won’t even look at your permit set. That two-stage approval defines the front end of every garage conversion we do here. Here’s the full sequence.
Stage 1: ARC submission, survey, and structural assessment (Weeks 1-3)
We pull a full survey of your lot to confirm setbacks and easements, then prepare the architectural submission for Lely Resort’s Architectural Review Committee. This packet includes exterior finish samples, roofline drawings, and window specs that match the community’s material palette. While we wait for ARC approval, our structural engineer evaluates the existing slab, stem walls, and roof framing to determine what the 2023 Florida Building Code requires for this specific garage. That report dictates every decision that follows. You choose the ADU’s rough layout during this stage so the architect can coordinate structural requirements with your floor plan.
Stage 2: Permit drawings and Collier County submittal (Weeks 3-5)
With ARC approval in hand, we submit full construction drawings to Collier County Building & Permitting for plan review. The plans include foundation details (especially if we’re raising the slab to meet finished floor elevation above the garage’s original grade), structural upgrades for wind load, MEP layouts, and energy calculations. Lely’s water table sits as little as 18 inches below grade in some zones, so any plumbing trenching under the slab gets flagged early if dewatering will be required. Plan review typically takes two to three weeks. We don’t touch the garage until we have a green tag.
Stage 3: Slab, rough plumbing, and weatherproofing (Weeks 5-8)
If the existing slab needs to be cut for bathroom or kitchen plumbing, we saw-cut, trench, and run drain lines and supply. Where groundwater shows up, we run dewatering pumps so concrete cures properly. New concrete ties into the existing stem wall with epoxy-set rebar. Once the slab is done and plumbing stubbed, we frame any interior partition walls, rough in electrical, and install new impact-rated windows and exterior doors. A garage door opening usually gets replaced with a wall assembly that matches the house’s exterior finish and a man-door. The goal by week eight is a dried-in, lockable shell.
Stage 4: HVAC, insulation, drywall, and finishes (Weeks 8-12)
Lely’s old single-pane garage doors and uninsulated walls make for brutal summer heat gain. We spray-foam the ceiling deck and insulate exterior walls to meet current energy code, then hang and finish drywall. At this stage, our electricians install the subpanel, lighting, and receptacle layout. Plumbers set the bathroom fixtures, the kitchen sink, and the water heater. Our flooring crew lays the flooring you selected. Cabinet install, countertops, and trim follow. Every trade is background-checked and uniformed, someone you’d recognize on your property.
Stage 5: Final MEP trim, punch list, and Collier County final inspection (Weeks 12-16)
We trim out all electrical, plumbing, and mechanical. Appliances go in. Painters do final touch-ups. Our site supervisor walks the unit with you to build a punch list, and we don’t call final inspection until you’re satisfied. Once the inspector signs off, we hand you the keys and a package with all permit-closure documentation, appliance manuals, and warranty information. The whole project is covered by our 730-Day Done Right Promise: if something isn’t right, we make it right.
The options you’ll choose between for your Lely garage conversion
Every choice changes the cost and how the space lives. Here are the five decisions that matter most.
- Unit size and layout. A 300-square-foot studio is the simplest conversion and costs the least. A two-car garage turned into a full one-bedroom with a separate bedroom runs the top end. The more walls and doors, the more electrical circuits and HVAC branch runs you need.
- Kitchen type. A wet bar with a sink, undercounter fridge, and microwave starts around $4,000. A full kitchen with a range, vent hood, dishwasher, and 8 feet of cabinetry typically runs $10,000-$18,000 depending on cabinet line and countertop material. Homeowners who also want updated surfaces in the main house sometimes pair this with Cabinets & Countertops in Lely and Backsplash, Tile & Flooring in Lely work done concurrently.
- Bathroom scope. A three-quarter bath (shower, toilet, vanity) is standard for ADUs. Adding a tub or expanding to a full bath with a linen closet adds plumbing fixtures and square footage, and typically pushes the plumbing budget up by $2,500-$5,000.
- Flooring throughout. Luxury vinyl plank handles Lely’s humidity without swelling, costs $4-$8 per square foot installed, and is the most common choice. Porcelain tile costs more but lasts longer. Solid hardwood is a risk in high-moisture months unless you run the mini-split in dehumidify mode year-round.
- HVAC system. Most garage conversions use a ductless mini-split heat pump sized for the square footage. A single-zone system runs $3,500-$6,000 installed. Tapping into the main house’s central system requires a Manual J load calculation and often a larger outdoor condenser, which adds cost but keeps the exterior cleaner for Home Additions & ADU in Lely projects where the ADU is part of a full addition.
What a garage conversion ADU costs in Lely, FL
You’ll spend between $45,000 and $130,000 converting a garage to an ADU in Lely. A basic studio in a single-car garage with a kitchenette and three-quarter bath starts around $45,000-$55,000. A one-bedroom out of a two-car garage with a full kitchen, separate bedroom, in-unit laundry, and higher-end finishes runs $80,000-$130,000. Every estimate we write is a fixed-price, line-item quote so you see exactly where your money goes before we order the first 2×4.
The four variables that push a job to the high end or low end are predictable. Garage size is the biggest driver: a 240-square-foot single-car space vs. a 480-square-foot two-car space doubles the conditioned square footage. Slab condition comes next: if the slab was poured below the house’s finished floor and has no vapor barrier, we’re cutting, pouring, and waterproofing from scratch. The third variable is plumbing relocation. Running a new sewer line across a slab that sits near Lely’s high water table often means dewatering pumps and possibly a grinder pump if gravity drainage won’t work. Fourth is finish level. Standard trim, stock cabinets, and laminate counters keep costs in the low $50s. Custom cabinets, quartz counters, tile showers, and impact-rated sliding glass doors push the number into six figures.
Every estimate includes demolition, structural upgrades, slab work, rough and finish plumbing, rough and finish electrical, HVAC, insulation, drywall, paint, flooring, fixtures, and the permit package. It does not include solar panels, EV charger circuits, or furniture. If you want to add those, we’ll line-item them separately so nothing surprises you.
How Lely homes specifically shape a garage conversion
Lely Resort’s Architectural Review Committee approval isn’t optional. It’s the gate that opens or closes every project. We submit exterior finish samples, window schedules, and roofline drawings that match the community’s palette before Collier County sees a permit application. Contractors who skip this step or assume the county will process the permit without ARC sign-off get rejected. We’ve navigated Lely’s ARC requirements across enough units to know which stucco textures, paint colors, and window mullion patterns pass the first time.
The housing stock here is almost entirely 1990s and early 2000s concrete block stucco construction, with original single-pane windows and pre-2002 hurricane code assemblies that no longer satisfy current Florida Building Code wind-load requirements. When we open a garage wall, we’re almost always adding Simpson Strong-Tie straps or anchor bolts to bring the structure up to current code. The original barrel tile roofs on many Lely Resort homes also affect the ADU’s roofline: we have to match the existing pitch and tile profile where the converted garage meets the main roof, which is an ARC requirement and a water-shedding necessity during Lely’s summer rainy season.
One operational reality worth knowing: a large share of Lely’s homeowners schedule major work during the May through October window while they’re out of state. That’s also peak rainy season, when afternoon thunderstorms shut down exterior work and humidity extends drywall mud and stucco cure times. We build two weeks of weather buffer into every summer schedule so the completion date doesn’t slide.
We work across the entire Lely footprint, from the villages along Lely Resort Boulevard to the golf-front properties along Grand Lely Drive, and our Home Additions & ADU crew knows the Collier County inspector sequence and what each inspector looks for on a garage conversion. That institutional knowledge shaves weeks off the permit-to-final timeline compared to a contractor who drives down from Fort Myers and sees the ARC process for the first time.
Serving Lely, FL - Our Local Coverage Area
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Frequently asked - Garage Conversion ADU in Lely
Yes. Lely Resort requires Architectural Review Committee approval before Collier County will process a building permit. Both approvals are mandatory. Converting a garage without permits creates problems when you sell the property, and unpermitted living space cannot be counted in square footage or bedroom count.
Plan on 12 to 16 weeks from the day we submit the ARC application to the day Collier County signs off on final inspection. The ARC and county plan review run concurrently where possible, but the two-stage nature of the approval process means the front end moves slower in Lely than in non-HOA jurisdictions. The construction phase itself is typically 8 to 10 weeks once permits are in hand.
You still need a bathroom and kitchen, which means plumbing goes where no plumbing currently exists. The slab gets cut and trenched. Structurally, the garage opening that held the vehicle door gets reframed into an exterior wall assembly, the ceiling gets engineered for added insulation and drywall weight, and the entire shell must meet current wind-load code. Even a minimalist conversion involves structural and plumbing work.
Most garage conversions in Lely fall between $45,000 and $130,000, with the median project around $70,000 for a comfortably finished one-bedroom unit. A studio with a kitchenette and three-quarter bath can run as low as $45,000. A two-car garage turned into a full one-bedroom with custom finishes approaches $130,000. We provide a written, fixed-price estimate before work starts. Call us at (844) 638-7249 to schedule yours.
Every garage conversion ADU we build is covered by our 730-Day Done Right Promise. If something isn’t done right within two full years of completion, we make it right at no cost to you. It’s one of the longest workmanship guarantees in residential construction, and it’s in your contract, not just on our website.
Schedule your free garage conversion ADU estimate in Lely
We’ll walk your garage, take measurements, talk through what’s possible under Lely’s ARC guidelines and Collier County code, and send you a detailed line-item estimate within a few days. The estimate is free and there’s no obligation. We answer our phones with a live person, 24 hours a day, seven days a week. Call (844) 638-7249 or use the contact form on this page to get on our schedule. From foundation to finish line, we do the whole job with background-checked, uniformed crews and upfront pricing that holds.
Written by Derek Hollenbeck, Owner at Groundwork Construction Co., serving Lely and surrounding communities since 2014.