How much does a Junior ADU & Interior Conversion cost in Gateway, FL?
How we build a Junior ADU & Interior Conversion in Gateway homes
1. Site review and architectural approval prep
Before a single tool comes out, we document the existing space, confirm the scope, and prepare whatever the Gateway Architectural Review Committee requires. This CDD-governed community reviews material choices, exterior changes, and even door styles before Lee County permits are issued. We handle that submission on your behalf, so the first hands the job touches are ours, and the approval timeline stays predictable.
2. Selective demolition and rough-in inspections
Once the approval clears, our crew opens walls to the extent needed. That might mean removing non-load-bearing partitions, exposing subfloor, or cutting in for a new exterior entry if the conversion needs its own access. We schedule the rough-in inspections for any new electrical, plumbing, or mechanical runs right here, so the job isn’t waiting on the county later. This stage typically runs 5 to 10 business days, depending on the home’s existing condition and how much of the original framing we keep.
3. Structural, insulation, and drywall
With rough inspections signed off, we reframe for any new window or door openings, insulate to current Florida Building Code minimums, and hang drywall. For interior conversions inside existing conditioned space, this stage moves fast. If we’re adding even a small wet bar or bathroom rough-in, the plumber and electrician will have set their stub-outs during rough-in, so taping and floating the walls closes everything up cleanly. Most homeowners are walking a finished, painted shell by the end of week four or five.
4. Finish work: when choices become real
Flooring, millwork, cabinetry, countertops, and fixture trim happen here. This is the stage where the decisions you made in week two about cabinet door profiles, quartz color, and LVP finish start looking like a finished unit. If the conversion includes a kitchenette, we’ll be setting appliances, connecting the sink, and testing every outlet. Expect a two- to three-week window for finish work, slightly longer if custom cabinetry lead times in the Fort Myers supply chain are still stretching from the post-Ian backlog.
5. Final inspection and CDD close-out
Lee County performs its final inspection, and we button up any last items the inspector flags. After that, we submit the required close-out documentation to the Gateway CDD, confirming the completed work meets the architectural approval originally issued. You get a clean, permitted, CDD-compliant Junior ADU, and we stand behind every inch of it with our 730-Day Done Right Promise.
The options you’ll choose between
Every conversion is a series of real trade-offs. Here are the decisions that shape the project most:
- Interior-only conversion vs. adding an exterior door. Keeping the ADU accessed from inside the main house saves thousands in foundation cutting, header framing, and stucco patching. Adding a private entrance improves rental potential but triggers more architectural review and costs $4,000-$8,000 more in a typical Gateway block-construction home.
- Wet bar vs. full kitchenette. A wet bar with a sink, undercounter fridge, and microwave lands on the lower end. A full kitchenette with a 24-inch range, vented hood, and dishwasher requires a gas or 240V electrical run and mechanical ventilation that adds $6,000-$12,000 to the budget.
- Flooring grade. Luxury vinyl plank holds up beautifully in Florida humidity, resists scratches, and costs less installed than engineered hardwood. Tile is cooler underfoot and nearly indestructible but adds labor. We stock a range of LVP from brands our crews trust, and you’ll see samples before we order a single box.
- Bathroom scope. A half-bath addition costs far less than a three-piece with a shower. Adding even a compact 30-by-30-inch shower stall requires a hot-water tie-in, a vent fan to exterior, and a waterproofed pan, which is the single largest cost driver inside the conversion.
- Window and door packages. In a 1990s Gateway home, original single-pane aluminum windows are often still in place. If the conversion room has them, upgrading to impact-rated units at the same time avoids opening the walls twice. Andersen and Pella options are available, and we’ll quote the difference up front.
What Junior ADU & Interior Conversion costs in Gateway, FL
The ballpark is $45,000 to $130,000. Where your project lands depends on a handful of measurable variables, not on guesswork. The size of the space is the biggest lever: a 300-square-foot bonus room conversion costs far less than converting a 600-square-foot section of the home with its own plumbing. Whether you add a bathroom or kitchenette is the second-largest driver. A dry living space with no new plumbing can stay under $60,000. Add a three-piece bathroom and a kitchenette, and the project routinely reaches six figures.
Other factors include the existing electrical panel capacity, whether we need to relocate load-bearing walls, and the finish level you choose. Our written estimates are line-itemed so you see exactly what drives the cost. You’ll never get a change order because we forgot to include a permit fee or a required architectural review submission. We also offer 0% financing for 18 months and $1,000 off projects over $10,000, which brings a $50,000 conversion down to $49,000 before any financing savings. Call (844) 638-7249 for a free estimate built on your actual floor plan.
What Gateway homes specifically do to this job
Gateway is a master-planned CDD, which means your conversion doesn’t start with the county. It starts with the community’s architectural review committee. We submit material specs, door styles, paint colors, and any exterior alteration details before Lee County even sees a permit application. Contractors who skip that step or treat it like an afterthought add weeks of delay. We’ve done enough projects here to know exactly what the committee looks for, from approved exterior door profiles to acceptable window frame finishes. That front-loaded paperwork keeps your timeline honest.
The housing stock itself works in our favor. Most Gateway homes are concrete-block construction with truss roofs, built between 1990 and 2010. The interior floor plans often have generous bonus rooms or formal living spaces that convert cleanly without moving structural walls. However, many of these homes still carry original single-pane windows and pre-Ian roof underlayment. If your conversion touches an exterior wall or requires new fenestration, it’s cost-efficient to upgrade to impact-rated windows in that section while the walls are open. Our crews are familiar with the specific framing and stucco details on these builds, so we’re not learning as we go.
The post-Hurricane Ian backlog across Lee County also affects this job. Material lead times, especially on custom windows and millwork, run longer here than in markets without sustained reconstruction demand. We order materials early in the process and track deliveries so your start date doesn’t drift. For homeowners looking at a broader scope, this kind of conversion often rolls into a larger Home Additions & ADU in Gateway plan, and we’ll coordinate with the full Home Additions & ADU team so the pieces fit together.
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Frequently asked - Junior ADU & Interior Conversion in Gateway
How long does a Junior ADU & Interior Conversion take in Gateway?
Ten to sixteen weeks is the realistic window. The Gateway CDD architectural review typically adds two to three weeks up front, and the county inspection schedule in Lee County can add another week between rough and final. We include that buffer in our timeline so you’re not surprised.
Do I need a permit for an interior conversion in Gateway?
Yes. Any work that adds living space, a bathroom, a kitchenette, or changes the exterior envelope requires a Lee County building permit, and the Gateway CDD requires architectural review before that permit is issued. We pull both and manage the process from submission to final sign-off.
Can I add a bathroom without tearing up the whole slab?
In most Gateway homes, yes, but it depends on where the conversion sits relative to existing drain lines. Many block-construction floor plans allow us to tie into an adjacent bathroom’s plumbing stack with limited slab cutting. We’ll camera your existing lines early in the assessment so you know the scope before we price the job.
What does a Junior ADU add to home value in Gateway?
A permitted, CDD-compliant Junior ADU with a private entrance and at least a kitchenette typically appraises as additional living square footage. The exact return depends on the finish level and whether it functions as a true independent unit. Many Gateway homeowners pair this with a Small & Partial Kitchen Remodel in the main house to create a cohesive plan. We can connect you with an appraiser who knows the Gateway market well.
Will the price change once work starts?
The number on our written estimate is the number you pay unless you ask us to expand the scope. We don’t run change orders on things we should have caught during measurement. If we open a wall and find something unexpected, we’ll show you photos and give you a price before we touch it. No hidden fees. That’s what upfront pricing means, and it’s backed by 42 years of serving communities across Florida.
Schedule your free estimate in Gateway
If you’re ready to turn unused square footage into a permitted Junior ADU, call (844) 638-7249 and ask for a free on-site estimate. We’ll measure the space, talk through the approval path with the Gateway CDD, and give you a line-itemed price before you commit to anything. Estimates are free, and our team answers calls with a live person, 24/7. No voicemail, no waiting until Monday.
Written by Derek Hollenbeck, Owner at Groundwork Construction Co., serving Gateway and Lee County with quality construction and straight answers since 2014.