What a New Detached ADU in Iona Actually Involves, and What It Costs
A new detached ADU in Iona is a fully independent living unit built from the ground up on your property, separate from your main house, with its own kitchen, bathroom, bedroom, and entrance. We’re talking a complete small home, roughly 600 to 1,200 square feet, sitting anywhere from six to twenty feet from the primary structure. In Iona, you should budget $90,000 to $220,000 for a turnkey unit, with most canal-front and post-Ian elevated builds landing in the $150,000 to $190,000 range. That includes everything from site prep and foundation through drywall, finishes, appliances, and the final Lee County sign-off. Call (844) 638-7249 when you’re ready to walk your lot and get a real number.
How We Build a Detached ADU from Bare Dirt to Move-In Ready
Every detached ADU in Iona follows a clear sequence. There are no mysteries here, just five stages that move from paper to concrete to paint. Here’s what you’ll actually see happen, and when you’ll need to make decisions.
Stage 1: Site walk, survey, and permit package. This takes two to four weeks, and it’s where the project gets its footing. We walk the lot with you to pin down the ADU’s location relative to setbacks, easements, existing utilities, and any seawall or flood-zone boundary lines. A licensed surveyor stakes the footprint. Our design team draws the plans to meet Lee County’s current Florida Building Code and any post-Hurricane Ian elevation requirements that apply to your parcel. The permit package goes into Lee County Building Department, and we manage the review cycle. You’ll choose your floor plan layout and exterior finish style here.
Stage 2: Foundation and underground rough-ins. Count on one to three weeks, depending on whether we’re pouring a standard slab-on-grade or an elevated stem-wall foundation to meet Base Flood Elevation. We excavate, form, and pour the concrete, then run the below-slab plumbing, electrical conduit, and any data lines. An inspection happens before we backfill. If your lot sits on a finger canal, this is the stage where a seawall certification letter from a marine engineer may be required before the county signs off on the foundation inspection. We coordinate that early so it doesn’t stall the job.
Stage 3: Framing, sheathing, and dried-in structure. This runs two to three weeks. Walls go up, roof trusses get set, the building gets wrapped and roofed. In Iona’s afternoon thunderstorm cycle, we time roof decking and underlayment for morning work windows so nothing gets soaked before the dry-in is complete. You’ll walk through the framed space with us to confirm window and door placements feel right, and we’ll rough in the window and door openings for the units you selected.
Stage 4: Mechanical rough-ins, drywall, and interior close-up. Four to six weeks. This is where the ADU starts looking like a home. Electricians wire every room. Plumbers set the shower pan, tub, and run supply lines. HVAC ductwork or mini-split lines go in. Insulation, drywall, tape, and texture follow. We install doors, trim, and baseboards, then paint. You’ll choose your flooring material, cabinet finish, countertop, and plumbing fixture style before this stage kicks off, so materials are on site when the crew is ready.
Stage 5: Finishes, fixtures, appliances, and final inspections. Two to three weeks. Flooring goes down, cabinets and countertops are set, light fixtures and plumbing trim are installed, appliances are connected. We handle every Lee County inspection: building final, electrical final, plumbing final, mechanical final. Once the county signs the completion card, we do a walkthrough with you, hand over keys and warranty documentation, and the ADU is yours. From permit submission to final sign-off, most new detached ADU projects in Iona run five to seven months, with the dry-season months of October through May being the most predictable build window.
The Options You’ll Choose Between for Your Detached ADU
An ADU is a small house, so you’re making real material and system choices. These are the ones that affect how the unit lives and lasts.
- Foundation type: slab-on-grade vs. elevated stem wall. Slab-on-grade is the lower-cost option and works well on lots already at or above Base Flood Elevation. An elevated stem-wall foundation adds $12,000 to $25,000 but may be non-negotiable on low-lying Iona canal parcels where the county’s substantial-improvement rules kick in. We’ll tell you which one your lot needs before we draw a single line.
- Exterior finish: HardiePlank lap siding vs. stucco over CBS. Stucco on concrete block is the classic southwest Florida look and holds up to salt air. HardiePlank fiber cement siding gives you a different architectural look and, paired with the right sheathing, handles hurricane-driven rain well. Both are solid options. Cost difference is modest, roughly $2,000 to $4,000 on a typical ADU footprint.
- Kitchen cabinet grade: stock vs. semi-custom. Stock cabinets from a line like KraftMaid give you clean, durable storage at a predictable price. Semi-custom lets you adjust dimensions and door styles further. The jump is typically $3,000 to $6,000 for an ADU kitchen, and it’s worth it if you want full-extension drawers and specific organizational inserts.
- Countertop material: quartz vs. granite vs. solid surface. Quartz is the most popular choice right now for a reason. It’s non-porous, stain-resistant, and requires zero sealing. Granite is more heat-tolerant but needs periodic sealing. Solid surface offers seamless integration and repairability at a slightly lower cost. Expect a $1,500 to $3,500 spread on an ADU’s worth of countertops depending on what you pick.
- Flooring: luxury vinyl plank vs. tile vs. engineered wood. LVP handles Iona’s humidity and occasional tracked-in sand beautifully and is the most budget-friendly. Porcelain tile is virtually indestructible and stays cool underfoot. Engineered wood gives you the real-wood look but needs more care in a high-moisture environment. The material itself ranges from $4 to $12 per square foot installed.
- HVAC: ducted central system vs. ductless mini-split. A ducted system is quieter and distributes air more evenly but steals ceiling space for ductwork. Mini-splits are hyper-efficient, give you zone control per room, and free up attic or ceiling space. Both cool a small ADU well. We size the system to the unit’s Manual J load calculation, not a rule of thumb.
What a New Detached ADU Costs in Iona, FL
A new detached ADU in Iona runs $90,000 to $220,000. That range isn’t vague once you know what pushes the number. The single biggest driver is square footage. A compact 600-square-foot studio with a kitchenette and three-quarter bath sits near the low end. A two-bedroom 1,200-square-foot unit with a full kitchen, one and a half baths, and its own laundry lands at the high end.
The second variable is foundation elevation. If Lee County’s post-Ian flood maps require raising the finished floor three or more feet above grade, the added concrete, fill, and stair construction runs $12,000 to $25,000 and sometimes more on deep canal lots. Utility runs are the third factor. Trenching a new water service and electrical feed across a long lot adds $3,000 to $8,000 depending on distance and soil. Fourth, finish level. A unit with stock cabinets, LVP flooring, and basic quartz counters costs materially less than one with semi-custom cabinets, porcelain tile, stone countertops, and impact-rated windows throughout. Fifth, site access. If the ADU goes in a tight backyard with limited machine access, labor hours increase for material handling and excavation.
Every estimate we write in Iona is a line-item proposal. It breaks down site work, foundation, framing, roofing, mechanicals, finishes, and permit costs separately. What’s always included: the full permit package and county inspection coordination, all labor and materials, a dedicated project lead, and the 730-Day Done Right Promise. What’s typically not included: impact fees Lee County may assess, separate seawall engineering if required, and owner-supplied appliances beyond the basic range, refrigerator, and dishwasher we spec. We walk you through every line before you sign anything. No change orders appear halfway through because we did the discovery work up front.
What Iona Homes Specifically Do to This Job
Building a detached ADU in Iona is not the same as building one in Cape Coral or Fort Myers. Iona is unincorporated Lee County, so every permit runs through the Lee County Building Department downtown, not through a city hall. The department is still working through a deep backlog of Hurricane Ian substantial-improvement reviews, and that means permit cycles here run longer than in neighboring municipalities. We budget four to six weeks for plan review on a new ADU in Iona right now, not the two to three you might see elsewhere.
The housing stock matters too. Most Iona homes are 1970s-to-1990s concrete-block construction on slab, and many of those slabs sit below the current Base Flood Elevation. If your existing home has been designated substantially damaged or if the ADU project, combined with other recent work, crosses the 50% improvement threshold, Lee County will require the ADU’s finished floor to be elevated. That’s not a suggestion. It’s a condition of the permit, and it changes the foundation from a simple slab to a stem-wall or pier-supported system. We’ve designed ADUs on Iona canal lots where the finished floor ended up seven feet above grade to satisfy FEMA and county requirements. That’s a different project than an ADU on a high-and-dry inland lot, and it requires a contractor who knows the Lee County elevation certificate and LOMC process.
One more Iona-specific wrinkle: seawall certification. On canal-front parcels, Lee County now frequently requires a signed letter from a licensed marine engineer certifying that the existing seawall is structurally sound before they’ll issue a building permit for any new structure. We line up that inspection during Stage 1 so the letter is in the permit package when it’s submitted. Out-of-town contractors often miss this step and lose weeks when the county kicks the application back. If you’re also planning a broader Home Additions & ADU in Iona scope, we coordinate the ADU foundation design with any work on the main house so the two structures are permitted as a single, coherent site plan.
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Frequently Asked Questions About New Detached ADUs in Iona
Five to seven months, from the day we submit the permit package to the day Lee County signs the final inspection card. Permit review alone typically takes four to six weeks in Iona due to the county’s ongoing post-Ian workload. The construction phase runs four to five months, with the October-through-May dry season being the most reliable window for foundation and framing work. Seawall certification, if required on a canal lot, can add two to three weeks to the front end if it’s not addressed early. We build that buffer into the schedule from the start. Call (844) 638-7249 for a timeline specific to your lot.
Yes, a full building permit from Lee County Building Department is required for any new detached ADU in Iona. The project needs architectural plans, a site plan showing setbacks and easements, a foundation design that meets current flood elevation requirements, and separate mechanical, electrical, and plumbing permits. We prepare the entire package in-house, submit it, and manage every cycle of review and correction. You don’t chase anything. The county inspects at foundation, framing rough-in, insulation, and final completion stages. We’re on site for all of them.
It depends on the existing panel’s capacity and the ADU’s electrical load. A small studio ADU with a mini-split, basic kitchen, and no electric dryer or car charger can often run off a 200-amp main panel that has spare breaker slots. A larger two-bedroom unit with a full electric range, dryer, dishwasher, and central AC usually requires either a sub-panel or a main panel upgrade to 400 amps. We evaluate your existing service during the site walk and include any panel work in the estimate so there’s no mid-project surprise. If you’re also planning a Kitchen Design & Layout in Iona project on the main house, we coordinate the electrical loads for both so you don’t end up paying for two separate panel upgrades.
A new detached ADU in Iona typically runs $90,000 to $220,000, while a garage conversion sits in the $30,000 to $80,000 range. The gap comes down to foundation and shell costs. A garage conversion is reworking an existing structure. A detached ADU requires a new foundation, full framing, roofing, and exterior envelope from scratch. The detached unit gives you a fully independent structure with its own architectural character and no shared walls. The conversion saves money but is limited by the garage’s existing footprint. Both need Lee County permits. Both get the 730-Day Done Right Promise.
We build the entire ADU from foundation to finish line. That includes site prep, foundation, framing, roofing, siding, windows, doors, plumbing, electrical, HVAC, drywall, paint, flooring, cabinets, countertops, trim, appliances, and every Lee County inspection. You deal with one company, one project lead, one timeline. Our Home Additions & ADU crew is background-checked, uniformed, and on site consistently through the whole build. We don’t sub out the project management to a third party and we don’t hand you off to a separate GC after the foundation is poured. If you’re also thinking about interior finish work like Backsplash, Tile & Flooring in Iona, we can sequence that so the ADU finishes don’t interfere with work going on inside the main house.
Get a Free, Line-Item Estimate for Your Detached ADU in Iona
Every ADU project starts with a no-charge site visit. Derek Hollenbeck will walk your lot, take measurements, check setbacks, assess the electrical service, and talk through what’s realistic given your property’s flood zone and county requirements. You’ll get a written estimate with every cost broken out by stage - no lump-sum mystery number, no change-order games. Call (844) 638-7249 to schedule yours. A live person answers, day or night, and we’ll have someone at your property within days, not weeks. The estimate is free, and so is the straight talk.
Written by Derek Hollenbeck, Owner at Groundwork Construction Co., providing new detached ADU construction in Iona with transparent pricing and the 730-Day Done Right Promise.