Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
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AfterFast, Reliable Home Additions & ADU Across Bonita Springs
A home addition or ADU in Bonita Springs typically runs $45,000 to $130,000 for a room addition, $90,000 to $220,000 for a detached ADU, and $30,000 to $80,000 for a garage conversion. Those are real numbers for this market, not national averages. If you live off Imperial Parkway, in Bonita Bay, or along a canal in the 34135 ZIP, the work has to meet stricter wind and flood rules than almost anywhere else in Lee County. Call (877) 610-1318 and we’ll walk you through what applies to your lot before you spend a dollar.
We’re Barrett & Sons Construction. Tom Barrett founded the company in 1998, and his sons run the crews that serve Bonita Springs from the South Florida metro office. When you call about a Home Additions & ADU project, you get a real person on the phone, every time, any hour. We know Bonita Springs zoning, we know the Lee County permitting queue, and we know what Hurricane Ian changed about how this city builds.
Key Takeaways:
- Room additions in Bonita Springs run $45,000-$130,000; detached ADUs run $90,000-$220,000; garage conversions run $30,000-$80,000.
- Post-Ian rules mean some properties face a 50% substantial damage threshold that forces full code compliance on the entire structure, not just new square footage.
- Every quote we give is in writing. Every change is a written change order before any work happens.
- We pull permits on every eligible job and get inspections signed. Tom’s name, address, and license number are published and verifiable.
Why Barrett & Sons Construction Is Bonita Springs’s Preferred Home Additions & ADU Company
Tom Barrett has put his name on every job since 1998. His sons are on-site most days in Bonita Springs, not a rotating cast of subcontractors dispatched from a call center. Ask anyone on your street, or look up the license number yourself. We want you to. That’s how a local company should operate.
Bonita Springs homeowners tell us the same story: a national outfit quoted one price on the phone, then handed them a different invoice at the door. We don’t work that way. Your scope is in writing. Allowances are in writing. If a product lead time shifts or you ask for a different window brand mid-job, you get a change order on paper before a single nail moves. The allowance that isn’t on paper is a surprise waiting for a date.
Live person answers the phone 24/7. Not a voicemail box. Not an out-of-state answering service. When a storm rolls through and you have a question about your project, someone who knows your file picks up.
Every completed job carries the 90-Day Done Right Promise, written on the contract. If something isn’t right, one call brings Tom back. No fine print. No argument.
Our Home Additions & ADU Services in Bonita Springs
We focus on the work Bonita Springs actually needs. Here’s what we handle most often for homeowners in this city:
ADU Design & Permitting
An ADU in Bonita Springs isn’t a set of stock plans dropped on your lot. Canal-front properties in ZIP 34134 and 34135 often sit in FEMA AE or VE flood zones, which means finished-floor elevation, breakaway wall design, and flood-resistant materials all become permit requirements. We handle design and the Lee County permit submittal as one package, so you’re not guessing at what the reviewer will flag.
Garage Conversion ADU
Converting a ground-level garage in Bonita Springs comes with a catch most contractors skip past: if your home took Ian damage and Lee County’s substantial damage assessment puts you over the 50% threshold, the conversion triggers full code compliance for the entire structure. We check that before we draw anything. A garage conversion ADU here runs $30,000 to $80,000 depending on whether you need elevation work, breakaway walls, or tie-down upgrades.
New Detached ADU
New builds in Bonita Springs have to meet current Florida Building Code wind-load standards from day one. That means engineered tie-downs, impact-rated openings, and a signed wind-load calculation included in the plan set. A detached ADU in Bonita Springs runs $90,000 to $220,000. We quote it with the products named, so you can look up the Simonton, PGT, or CGI window ratings yourself.
Junior ADU & Interior Conversion
A junior ADU inside the existing footprint, a converted bonus room, a split-off in-law suite. These tend to be the most cost-effective ADU path in Bonita Springs because they often avoid new foundation and floodplain triggers. We walk you through what qualifies under Lee County’s rules and what doesn’t.
What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
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 Bonita Springs
We carry and install brands you can verify. On ADU and addition windows and doors, we regularly quote Simonton, PGT, and CGI because their impact-rated product lines are engineered for the wind loads Bonita Springs structures face. Ply Gem rounds out the mid-range options. If you want to look up a product’s Miami-Dade NOA or Florida Product Approval before signing, we’ll give you the exact model number. No mystery brands off a van.
Common Home Additions & ADU Problems We See in Bonita Springs Homes
- Substantial damage assessments skipped. A homeowner starts a room addition, the permit gets flagged because Ian damage plus new scope crosses the 50% threshold, and suddenly the whole house has to rise to current flood elevation. We check the Lee County assessment before the first drawing.
- Standard truss packages without signed wind-load calcs. In Bonita Springs, if the roof framing doesn’t have a stamped wind-load calculation, the inspector rejects it. That’s months lost in the post-Ian permitting queue, and the homeowner pays for it twice.
- Garage conversions with solid walls below base flood elevation. In a VE zone, non-breakaway walls below BFE fail inspection and have to come out. It’s a tear-out that never should have happened with a competent design review.
- Old CBS tie-downs that don’t meet current uplift requirements. Homes from the 1970s through early 1990s in older inland Bonita Springs sections often have 3-inch anchor bolts. Current code requires 5-inch HDG hardware for new second-story and addition work. An inspector will check. We upgrade before we frame, not after.
Pricing for Home Additions & ADU in Bonita Springs, FL
Here are the numbers we quote in Bonita Springs right now:
| Scope | Typical Range in Bonita Springs |
|---|---|
| Room Addition | $45,000 - $130,000 |
| ADU Construction | $90,000 - $220,000 |
| Garage Conversion ADU | $30,000 - $80,000 |
What moves the number? Flood zone designation is the big one. A canal-front lot in 34134 or 34135 that requires elevation, breakaway walls, and flood-resistant materials costs more than an inland lot in 34136. Second: the existing structure’s tie-down condition. Third: product choices, impact-rated windows and doors cost more than non-impact, but they also earn Florida wind-mitigation credits on your insurance. We give you a written line-item quote so you can see exactly where the dollars go. Call (877) 610-1318 for a free estimate on your Bonita Springs project.
Why Bonita Springs Wind and Flood Rules Change Your Quote
Bonita Springs sits where the Imperial River meets Estero Bay, and much of the city drains into a network of residential canals. That geography means some of the lowest average ground elevations in Lee County and large areas in FEMA AE and VE flood zones. So a home addition or ADU on a canal-front lot in ZIP 34134 or 34135 often has to satisfy FEMA Substantial Improvement rules, current Florida Building Code wind-load provisions, and Lee County’s post-Ian permitting queue all at once. Even a modest room addition can force the entire structure to current flood elevation and wind code, not just the new square footage. A quote that ignores that is fiction.
We recently framed a second-story addition off a 1970s CBS ranch in the Imperial River corridor where the original tie-downs had to be upgraded from 3-inch to 5-inch HDG anchor bolts to meet current Florida Building Code uplift requirements before the inspector would sign off on the rough-in. Our crew coordinated the permit through Lee County’s post-Ian queue, added breakaway walls on the ground-level garage conversion, and kept a running change order log so the owner’s insurance carrier could verify every wind-mitigation credit. That’s the kind of project that only happens in a place like Bonita Springs, and it’s the work we know best.
In the 34135 ZIP specifically, many Ian-damaged homes that look structurally repairable are being flagged by Lee County assessors as exceeding the 50% substantial-damage threshold. That forces owners into full elevation-compliant rebuilds on raised stem walls or pilings instead of straightforward restoration. If you’re planning an addition in that area, this is the first thing we check, because it changes everything about your scope.
We Also Serve Cities Near Bonita Springs
Beyond Bonita Springs proper, our crews cover Estero, Naples Park, Pelican Bay, and San Carlos Park. If you’re in one of those communities and want the same written-scope, permitted, name-on-the-truck approach, call the same number. We serve all of Home Additions & ADU in Bonita Springs and the surrounding area with the same crew members and the same standards.
Serving Bonita Springs, FL - Our Local Coverage Area
We’re based in the Bonita Springs 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 Bonita Springs
If Lee County’s substantial damage assessment places your property above the 50% threshold, a garage conversion ADU triggers full code compliance for the entire structure, including flood elevation and wind-load upgrades beyond the garage footprint. We verify your property’s assessment status before we draw plans, so you don’t lose months in permitting on a scope that was doomed from the start. Call (877) 610-1318 and we’ll check your address.
A new second-story addition in Bonita Springs must meet current Florida Building Code wind-load requirements for the specific wind speed zone, which in practice means engineered tie-downs, a stamped wind-load calculation on the truss package, and impact-rated openings if the opening is required to be protected. The inspector will check the calculation against the structural plans. We include it in every second-story quote. Call (877) 610-1318 for a free estimate with the wind-load engineering spelled out.
In ZIP 34134, if your ground-level space sits below base flood elevation in a VE or AE flood zone, the non-structural walls below BFE must be breakaway walls that fail without damaging the elevated portion of the structure. Solid CMU or stucco walls below BFE won’t pass final inspection in those zones. We design the breakaway wall system as part of the permit set, not as an afterthought. Call (877) 610-1318 to confirm what applies to your lot.
Post-Ian, Lee County’s permit queue runs longer than pre-storm norms, often weeks to months depending on scope and zone. A missing wind-load calculation or skipped substantial damage review adds months. We submit complete plan sets the first time, which is the single biggest variable an owner can control. Call (877) 610-1318 and we’ll give you a realistic timeline for your specific Bonita Springs address.
A compliant ADU quote in Bonita Springs should include the substantial damage assessment check, the signed wind-load calculation, breakaway wall design if the property is in a flood zone, the permit submittal, named products with Florida Product Approval numbers, and a written change order process. A cheap quote that omits any of those will cost more by final inspection. We put all of it in writing up front. Call (877) 610-1318 for a line-item estimate.
Get Your Bonita Springs Home Addition or ADU Quote in Writing
Before you sign anything, get the scope in writing, the allowances in writing, and the change order process in writing. That’s how we work, every job, since 1998. Tom Barrett publishes his name, address, and license number. His sons run the crews in Bonita Springs. And every finished project is backed by the 90-Day Done Right Promise. Call (877) 610-1318 today to schedule your free estimate. Ask for Tom. He’ll answer.
Written by Tom Barrett, Owner at Barrett & Sons Construction, founded 1998 and serving Bonita Springs with permitted, written-scope home additions and ADU work since our first Lee County project.