Fast, Reliable New Detached ADU Across Fort Myers
A new detached ADU in Fort Myers typically costs $145,000 to $285,000 all-in for a custom build, drawings through final inspection, while a prefab or modular unit on a prepared site usually lands between $110,000 and $190,000 depending on the unit and your lot’s site work. Those are written prices, by the way - not estimates that drift once the slab is poured. We provide a written price before any work starts, per Clause 1 of our Haven Standard. If you’re weighing a backyard cottage in Fort Myers, call us at (971) 497-2402 and we’ll walk you through exactly what your lot can support, what the city and county will require, and what the real line items will be.

Our team knows Fort Myers not from a map but from project sites: the CBS ranch homes east of US-41, the post-Ian rebuild zones, and the McGregor Boulevard corridor where lot size says yes but a 1930s deed restriction might say no. We coordinate from our South Florida office and run crews locally in Fort Myers. The person who answers the phone is a person. That has always been the arrangement.
Why Ellery ADU Studio Is Fort Myers’s Preferred New Detached ADU Company
Ellery ADU Studio has designed, permitted, and built 900+ ADUs since 2015, every one of them under a single contract at a single written price. That number matters because it means we have already seen the failure modes that cost Fort Myers homeowners money: the septic drain field that wasn’t budgeted, the deed restriction that surfaces after design fees are spent, the post-Ian wind-load upgrade nobody quoted. We do not learn on your lot.
Our New Detached ADU practice is built on the permit set. We treat the drawings and the county submittal as the core product, not paperwork that happens to precede construction. Nadia Ellery founded the studio in 2015, the year California’s ADU permitting landscape shifted, and she has carried that same standard into every Florida project we run. For Fort Myers specifically, that means we know which City of Fort Myers parcels need FEMA elevation certificates, which Lee County flood zones trigger additional review, and which HOAs in newer master-planned communities will reject a detached ADU application on sight.
We also carry something most studios do not: documented photo records on every visit. When our crew is on your lot in Fort Myers, you receive evidence of what was found and what was done. Not a note saying “site looked fine.” Photographs. Dates. The scope, locked under Haven Standard Clause 5 (No Surprises).
Our New Detached ADU Services in Fort Myers

Custom Built ADU
A custom built ADU in Fort Myers runs $145,000 to $285,000 depending on square footage, foundation type, and wind-load requirements. If your lot sits in the high-velocity hurricane zone - which covers most of Lee County - expect framing, trusses, and impact-rated fenestration to cost 20-30% more than identical work inland. We specify every custom build to Florida Building Code wind-load standards, and the engineering goes into the permit set before the first inspection.

Prefab ADU Installation
Prefab ADU installation in Fort Myers starts around $110,000 and rises with site work, foundation, utility runs, and crane access. We specify and coordinate systems from Cover, Dvele, Mighty Buildings, and Boxabl within the same single contract. On tighter lots - common in Fort Myers’s established neighborhoods east of US-41 - prefab can be the fastest path to a finished unit, but it still requires the same city permits, the same elevation review, and the same septic analysis as a custom build.

Modular ADU
A modular ADU in Fort Myers typically lands between $125,000 and $210,000. The modular approach works well on quarter-acre-plus lots where a crane can stage. We have seen modular projects on McGregor Boulevard move faster because the unit arrives with finishes already installed, reducing on-site labor days during Fort Myers’s rainy season. What does not change: the county still reviews your parcel, your flood zone, and your sewer or septic capacity before the permit issues.

Studio ADU
A studio ADU in Fort Myers - typically 400 to 600 square feet - runs $130,000 to $205,000 custom-built. These units are the workhorse of Fort Myers’s snowbird rental market. A finished studio with impact windows and a standing-seam roof holds its value through hurricane season and rents strongly from November through April. We build them to the same wind-load standard as a full two-bedroom unit, because Lee County does not offer a discount for smaller buildings.

1-Bed & 2-Bed ADU
One-bedroom ADUs in Fort Myers run $150,000 to $235,000; two-bedroom units start around $170,000 and can exceed $285,000 with premium finishes and site complications. On a 0.4-acre lot off McGregor Boulevard, we framed a custom studio with impact-rated windows and a standing-seam roof engineered for 150+ mph wind loads. After zoning approval, our title check flagged a 1938 deed restriction prohibiting a second dwelling. We shifted the project to a nearby lot without the covenant and folded the ADU into the homeowner’s active Hurricane Ian rebuild permit. That is the difference between a studio that prices the drawings and a studio that reads the title.

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.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Fort Myers
We specify and coordinate prefab and modular systems from Cover, Dvele, and Boxabl, among others, for Fort Myers projects. Because we hold the contract with the manufacturer and the site crew, the unit’s engineering, delivery, and set are one scope - nobody can point at the other when a panel arrives late or a connection detail fails inspection. For Fort Myers customers, that means a single written price that covers the unit, the foundation, the utility runs, and the permit set. Nothing arrives on site that wasn’t in the drawings.
Common New Detached ADU Problems We See in Fort Myers Homes

- Deed restrictions that kill the project after zoning says yes. Along McGregor Boulevard, some of Fort Myers’s largest ADU-buildable lots carry 1920s-1940s subdivision covenants banning second dwellings outright. The city approves the zoning, permit fees get paid, and then a title review kills the project. We run title review before design dollars are spent.
- Septic systems nobody budgeted for. Many Fort Myers homes east of US-41 sit on private drain fields. Adding a detached ADU often triggers a mandatory drain-field expansion or a sewer tap that can add $15,000 to $40,000. We flag this in the first site review, not after the permit application.
- Post-Ian finish pricing assumptions. Builder-grade material and labor costs in Fort Myers surged after Hurricane Ian. Homeowners who expect 2019 rates on framing, trusses, and impact windows routinely blow their ADU budget by 20-30%. Our written price locks the scope before work starts, so the number does not drift.
- HOA architectural review in newer master-planned communities. Several Fort Myers HOAs prohibit detached ADUs entirely or require architectural committee approval before permit submission. We review the HOA’s recorded covenants during due diligence, not after you have paid for drawings.
Pricing for New Detached ADU in Fort Myers, FL
A custom detached ADU in Fort Myers runs $145,000 to $285,000. A prefab or modular unit on a prepared site lands between $110,000 and $190,000. What moves the number on your lot: wind-load engineering in the 150+ mph design zone, elevation certificate and flood-zone review if your parcel requires it, septic or sewer capacity, and the finish level you specify. On a master-planned Fort Myers home with builder-grade finishes, upgrading to impact-rated windows and a standing-seam roof on the ADU adds roughly $18,000 to $35,000 compared to standard glazing and shingle. Every price we give in Fort Myers is a written price, per Haven Standard Clause 1. No door-side upsells, no scope drift.
We Also Serve Cities Near Fort Myers

Our Fort Myers crews regularly work in Cape Coral, Sarasota, Bradenton, and Lakeland. If you are researching a New Detached ADU in Fort Myers and your property sits in a neighboring city, the same written-price standard and the same permit-set discipline apply. One contract, one written price, one accountable team.
Serving Fort Myers, FL - Our Local Coverage Area
We’re based in the Fort Myers 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 - New Detached ADU in Fort Myers

Some do and some explicitly prohibit them. Several newer master-planned communities in Fort Myers have recorded covenants that ban detached second dwellings outright or require HOA architectural committee approval before any permit submission. We review the subdivision’s recorded covenants and the HOA’s design guidelines during due diligence, before design money is spent. Call (971) 497-2402 and we will check your specific community’s rules at no charge.
A detached ADU built as a separate structure generally does not void the builder warranty on your primary home, because the work is not modifying the original dwelling’s structure, systems, or envelope. What can void portions of the warranty is tying into the home’s electrical panel, plumbing, or foundation in a way the builder’s warranty terms exclude. We document every connection point in the permit set, which gives you a written record to show the builder if a warranty dispute arises. If you have the warranty language, we will read it before we design anything.
They add time and cost. After Hurricane Ian, Lee County and the City of Fort Myers tightened permitting to require updated FEMA elevation certificates and flood-zone compliance review on many parcels before an ADU permit issues. If your lot sits in a flood zone that requires elevation, your ADU’s finished floor may need to sit higher than the existing grade, which adds foundation cost. Expect the review to add several weeks to the permit timeline. We build that into the schedule so it does not surprise you mid-project.
Yes, in many cases - but it may cost more than the ADU’s site work alone. A large share of Fort Myers homes east of US-41 remain on private drain fields, and adding a dwelling unit often triggers a mandatory drain-field expansion or a sewer tap from Lee County. That line item can run $15,000 to $40,000. We verify your septic capacity during the first site review and put the number in the written price, so it is not a surprise later.
Impact-rated windows and a standing-seam metal roof first. Both are required in many Fort Myers HOAs and both meaningfully improve hurricane-season durability and insurance positioning. After that, upgrade the HVAC to a high-efficiency unit sized for the ADU’s square footage - Florida’s humidity means undersized cooling turns a new unit into a mold risk. Builder-grade interior finishes are fine as-is in most cases; the structural and envelope upgrades are the ones that protect the asset.
Written by Nadia Ellery, Owner at Ellery ADU Studio, serving Fort Myers with written-price design-build ADU projects since 2015.