ADU housing laws and regulations in Jacksonville: 2026 guide

City Council passed Ordinance 2022-448-E by a 12-7 vote. The state statute behind local ADU ordinances, F.S. 163.31771, finds that the shortage of affordable rentals "constitutes a threat to the health, safety, and welfare of the residents of the state." Our guide to Florida's ADU laws covers the statewide framework. The ordinance amended Sec. 656.305 and Sec. 656.403 of the zoning code and added subsection 656.403(g), which holds nearly every rule you need for a go/no-go decision:

Two things in that table are in motion. Ordinance 2024-0870-E, introduced November 12, 2024, amends Sec. 656.403, and the City's agenda summary says it removes the requirement that an ADU sit on homestead property. One Legistar record shows an 18-0 Council approval on January 14, 2025, while the meeting record for the same date lists the bill as "PH Contd" with no enactment, and the City has not posted enacted text. The homestead condition stays the enforceable rule until the Zoning Section tells you otherwise.

Municode's Sec. 656.403 page still shows 2017 text, so use the Legistar ordinance text for ADU criteria.

Florida defines an ADU in F.S. 163.31771(2)(a) as "an ancillary or secondary living unit, that has a separate kitchen, bathroom, and sleeping area, existing either within the same structure, or on the same lot, as the primary dwelling unit." A converted garage with a kitchen and a backyard cottage both qualify. A walled-off wing of the main house also qualifies. A pool house with a bathroom and no kitchen does not.

Jacksonville's code adds two conditions. The unit must be accessory to a conforming single-family dwelling, and if it is attached, the plans must show it physically separated from the house with no direct internal access.

Permit difficulty tracks the build type:

• A detached cottage is permitted as a new building. You file the full one- and two-family plan set with sealed structural plans, a sealed truss package, energy calculations and a site plan, and you pay new-building permit fees by the 100 sq ft. It is the most expensive route and the one most exposed to flood-elevation and wind-design costs.
• A garage conversion is the cheapest route (see the cost table below) and is permitted as an alteration, with fees charged per $1,000 of estimated cost rather than by area. The code still treats the result as a habitable dwelling, so the space must meet egress, energy, separation and size rules, and on a flood-zone lot the 50% substantial-improvement test can pull the whole house into current elevation standards.
• An attached ADU follows the addition track on the same City checklist, which also asks for a current JEA bill rather than a new letter of service availability.
• A modular or prefab unit arrives with DBPR approval of the building itself, but the foundation, site work and utility connections stay under City permitting, and the local building official decides whether the engineered foundation plans for a pad- or block-supported unit comply. Mesocore, a modular builder, reports 3–4 months from application to certificate of occupancy for modular against 6–18 months for site-built; that is a vendor figure, not a City one.

ADUs are allowed by right as a permitted accessory use on conforming residential lots in the AGR, RR, LDR, MDR and RPI land use categories under the 2045 Future Land Use Element adopted in December 2025. No "by exception" pathway was identified, and none is needed; the Planning Commission only gets involved when you ask for a variance. The Beaches and Baldwin are excluded. Lots whose HOA prohibits ADUs are also excluded.

Those land use categories map to the following zoning districts under Sec. 656.305:

An ordinary subdivision lot zoned RLD-60 or RLD-70 qualifies. Look up your district on the Duval County GIS zoning map before you sketch anything, because the district sets your lot coverage ceiling and the yards the ADU has to stay out of:

Confirm with Zoning what counts toward lot coverage. Assuming the house and the ADU count along with every other roofed structure, a 2,000 sq ft house footprint on a 6,000 sq ft RLD-60 lot with a 50% cap leaves 1,000 sq ft for everything else, including the ADU, a shed and a covered porch.

Two setback rules overlap, and the code does not say which controls. The ADU criteria say the unit "shall not be located in a required yard," which means the full district rear yard of 10 ft applies. The general accessory-structure rule in Sec. 656.403 allows any structure under 15 ft tall to sit 5 ft from a rear or side lot line. Design to the 10 ft rear yard unless the Zoning Section confirms in writing that the 5 ft rule governs your unit. Municode can lag enacted ordinances, so the live code is the final word on any number you put on a permit drawing.

The size cap and the location rule can both be varied lot by lot. The results agenda records that on September 3, 2026, the Planning Commission approved an ADU in a front yard at 33% of the primary footprint (V-26-23) and a garage apartment enlarged from 690 sq ft to 884 sq ft (V-26-24). It also approved an ADU enlarged from 750 sq ft to 1,220 sq ft (V-26-25).

Every ADU permit starts as an online submission in JaxEPICS, and the Building Inspection Division's plan review clock does not start until Zoning, Concurrency and Development Services have approved the application and you have paid the plan review fee. The sequence from plan set to certificate of occupancy runs as follows:

1. Build the plan set to the City's "New Building – 1 & 2 Family Checklist (REVISED: 4/21/2026)," which covers new buildings, accessory structures and additions. It requires energy calculations (forms R402/R405/R406 or total UA, with ACCA Manual J at the 2023 8th Edition minimum), COJ-PAIS product approvals as a single PDF, a site or drainage plan or legal survey, digitally signed and sealed structural plans, a sealed truss package, and labeled emergency rescue openings in each sleeping room. A new building on an infill lot needs a JEA Letter of Service Availability; an accessory structure or addition needs a current JEA bill. A flood-hazard lot adds an Engineer of Record letter identifying BFE, DFE and finished floor elevation.
2. Submit everything through JaxEPICS. Sunshine State Professional Services, a local builder, reports that an incomplete set is returned rather than reviewed, and the clock restarts.
3. Development Services runs its reviews first. Zoning checks height, lot size and coverage, setbacks, the survey, covenants and the plat. Development Services checks the 35 ft frontage rule in Sec. 656.407, grading, floodplain and easement encroachments. The Concurrency and Mobility Management System Office checks mobility compliance. The Fire Marshal also reviews the plans.
4. Pay the mobility fee, which is "Pay & Go" and due before vertical construction or the building permit for single-family work unless the use is de minimis or exempt.
5. Wait out building plan review. The published service level is 25–30 business days for first review and about 10 business days or less for resubmittals. The Mayor's office reported residential first-review averages fell from 25 days to 8 by May 2025 and sat at 8 days residential and 13 commercial in August 2025; those are averages, so budget for the published figure.
6. Clear corrections. A permit that needs more information goes to "Return for Corrections." After issuance, you click "Revise," upload documents and click "Submit For Review" for any change.
7. Record a Notice of Commencement if job cost exceeds $5,000. It does not delay permit issuance, but no inspection gets scheduled without it.
8. Pass inspections and close out. Required inspections are listed at issuance and typically cover slab or foundation, framing, insulation, drywall, plumbing and electrical (rough and final), duct, A/C and gas. Underground work must pass before it is covered. Schedule online or at 904-255-8500 for the next business day; a failed inspection costs $45 to repeat. All fees must be paid before the final inspection request and the certificate of occupancy, and a residential temporary or partial CO costs $100.

State law backs the timeline. F.S. 553.792 requires a completeness notice within 5 business days and a decision within 30 business days of a complete application for accessory structures under 7,500 sq ft. You then have 10 business days for revisions, followed by 10 business days for the City's answer. Fees fall 10% per business day when the City runs late, or 20% on a late post-revision decision.

Faster tracks exist. Express Lane Permitting, announced August 28, 2025, targets under 30 days and took 18 days for the building permit in its first pilot, though the City had not set its added fee. News4JAX reported that AI-assisted review opened to developer opt-in on June 15, 2026 and is expected to trim 45–60 days from initial review.

You can also hire a private provider for plan review or inspection under F.S. 553.791. End-to-end, ADU Florida Info, a vendor guide, estimates 25–35 business days for plan review and 6–12 months total from application to occupancy.

Jacksonville has no ADU-specific fee line. The City prices a detached ADU as a new building and a garage conversion as an alteration, JEA bills water, sewer and electric on its own tariff, and the mobility fee is calculated per site rather than published as a flat rate.

City permit fees

Fees are set in Municipal Code Sec. 320.409 and listed on the City fee page, though the City publishes no ordinance number or effective date for the current schedule. New buildings up to the fourth story pay per 100 sq ft:

Alterations and conversions pay per $1,000 of estimated cost instead: $3.00 for the BID permit, $0.65 resource management and $1.00 Development Services, with plan review at 67% of the BID fee. A separate City page lists a $2.00-per-$1,000 conversion-of-use permit, and the two pages differ on the plan review floor ($75 in the Municode alterations text, $90 on the inspections page). Ask the Building Inspection Division which applies to a garage conversion before you price the job.

Minimums matter on a small unit. The BID permit fee is at least $112.50 or $33.75 per required inspection, whichever is greater, and the Development Services Fee is at least $37.50 or $11.25 per inspection. A foundation-only permit runs 25% of the calculated BID fee.

Mobility, concurrency, and school fees

The mobility fee is the closest thing Jacksonville has to a transportation impact fee, and no official dollar rate for an ADU exists. Ordinance 2022-909-E recalculated the fee in February 2023, and the December 2025 Transportation Element says the next revision will come by ordinance on an unstated schedule.

The only dollar figures come from a third party. impactfees.org estimated roughly $881–$2,650 for a new single-family home as of August 5, 2026, rising to $3,922 in Mobility Zone 6 (Rural), and noted there is no published per-square-foot or per-unit rate. Credits can reduce the bill: demolishing an existing-use structure yields a 125% trip subtraction and repurposing or remodeling yields 150%, both site-specific and non-transferable. Administrative charges include a $28 de minimis review and a $688 Mobility Fee Calculation Certificate ($266 expedited).

School and other impact fees do not apply. School concurrency came out of the Interlocal Agreement on November 6, 2017, and no standalone Duval school impact fee exists. Concurrency review for residential costs $21 per dwelling without a prior CCAS and $9 with one. The $250-per-lot recreation fee applies only to subdivisions of 25–99 lots. One vendor guide cites "impact fees" of $1,300–$2,000 for a garage conversion; the City publishes no schedule that supports that number.

JEA water, sewer, and electric

JEA has no ADU-specific policy, and its general residential rules point toward shared service. The 2025 Design Guidelines say "only one water service will be allowed for each lot," and JEA requires one 6-inch wastewater service per single-family lot, with double or "gang" services rejected outside commercial and multifamily systems. JEA does not meter sewer; the sewer Service Availability Charge follows water-meter size. Where no sewer line serves the lot, septic approval goes through the Florida Department of Health in Duval County.

Electric follows the same pattern. JEA's Electric Rules state that "normally, JEA shall provide only one point of service to a building or structure," with additional points possible where feasible and approved by the local inspection authority. Multiple services need a permanent plaque at each disconnect. All new permanent service must be underground, and interconnecting multiple JEA services through your own wiring is prohibited.

JEA publishes no rule on whether a detached ADU may be sub-fed from the main house meter. Mesocore, a builder, says shared connections and separate meters are both possible and prices separate metering at "$8,000–$15,000 typical"; that is not a JEA figure.

If you do pull a new connection, the JEA water and sewer tariff lists these charges:

The minimum new-water connection charge is the greater of the per-gallon charge or the plant capacity fee, plus the line-extension growth charge. JEA publishes two different figures: its residential tap application lists capacity fees of $339.50 water and $1,274 sewer for a 3/4" meter, so get a written estimate from JEA before you finalize a budget. The tariff also lists "construction of new dwellings" and "additions to existing dwellings" as events that can trigger added capacity charges when usage rises more than 20% over the last paid capacity.

Tap and meter-set fees are charged when you apply or when a plumbing permit is issued. The City wants the JEA bill or service letter in the permit submittal, so settle the service question with JEA at the plan-set stage.

Monthly costs follow the meter count. The RS Basic Monthly Charge is $21.00 per electric service, effective October 1, 2026, and JEA's rates page says the Customer Charge applies "for each electric service," which suggests a separately served ADU carries its own $21. A 3/4" water meter carries $18.23 water and $23.37 sewer in monthly availability charges under the December 1, 2025 tariff.

Rates are rising. JEA's board approved October 1, 2026 adjustments of 1.6%–3.1% on residential electric and 4.3%–7.5% on water and sewer, depending on usage.

Council auditors reported in July 2026 that JEA may have missed up to $75 million in capacity fees since 2003, with collection policies expected before the board in early 2027, so capacity-fee practice may tighten.

Jacksonville imposes no off-street parking requirement on an ADU. The only parking rule on the lot is the two spaces the single-family house already needs under Chapter 656, Part 6, which sets no maximum for single-family dwellings.

Tandem parking is unsettled. Sec. 656.607 requires parking areas for three or more cars to allow each car out without moving another, and the code expressly permits stacking only for townhouses and rowhouses under Sec. 656.415. Whether a driveway counts toward anything on an ADU lot is not addressed. The 25% transit reduction in Ordinance 2024-869 applies to duplexes through quadplexes, not ADUs, and the Daily Record reported in April 2025 that Council sank the missing-middle measures, so confirm the bill's status with the Council. The Springfield overlay (Sec. 656.369) requires no minimum parking at all except for churches.

The design standard is short. A new ADU needs a visual relationship to the main house through similar roof shape, porches and paint color; an existing structure converted to an ADU needs similar paint color and other characteristics. The criterion names no siding, window or style requirement, but a local builder guide from Sunshine State Professional Services (updated September 2026, no author named) reports that the match does come up in review.

The same guide lists the submittal errors that send plans back:

• Designing to 750 sq ft by default. The cap is the lesser of 750 sq ft and 25% of the principal structure, so a 2,400 sq ft house allows 600 sq ft, and 750 is reachable only behind a house of 3,000 sq ft or more.
• Placing the unit in a required yard, which bites hardest on narrow lots.
• Submitting an incomplete plan set.
• Treating a garage conversion as a finish-out rather than a habitable dwelling with its own egress, energy and separation requirements.
• Leaving the second unit's utility service unresolved with JEA until after submittal.

No official deficiency list exists. The checklist items (sealed plans, energy forms, egress labeling, the flood letter) show where reviewers look.

Builder and engineer estimates put a detached ADU in Jacksonville at roughly $120,000 to $420,000 all-in and a garage conversion at $55,000 to $145,000. None of those figures come from a methodology-driven cost index such as RSMeans, so they are ranges for checking bids against, not benchmarks.

Six builders and engineers publish Jacksonville figures by build type:

Derived from those vendor figures, Ofir's $55,000–$120,000 garage conversion for 400–600 sq ft works out to roughly $90–$300 per sq ft. Mesocore's Model E at $129,000 for 420 sq ft is about $307 per sq ft.

The cheapest path is a garage conversion, and the City prices a conversion as an alteration per $1,000 of cost rather than by area. Sunshine State identifies impact windows and doors at $3,000–$8,000+ and a mini-split system at $3,000–$7,000 as major cost drivers. Slab cutting for bathroom and kitchen drains can also push a conversion toward the top of its range.

Below the conversion range sit marketing floors rather than completed-project costs. TB Construction and Jax Tiny Homes advertise "From $85K," while a builder quoted by News4JAX in September 2025 said "studios going for about $70,000." A June 2024 News4JAX story advertised Anchored Tiny Homes "as low as $75,000" and described one roughly 500 sq ft unit at $130,000.

Mesocore's undated allowances run $3,000–$7,000 for a foundation and $3,000–$20,000 for utility connections. It lists $5,000–$15,000 for permits and $2,000–$25,000 for site prep, while an elevated foundation in a coastal or flood zone runs $20,000–$50,000.

One vendor advertises a "140+ mph" wind rating; the official design speed for Duval is 125 or 130 mph, so a higher rating is a selling point rather than a code requirement. Financing options include a HELOC or cash-out refinance and a construction loan.

Paying for an ADU

A HELOC or cash-out refinance draws on the equity in the primary home, so the owner-occupied house secures the money for the ADU.

A construction loan pays out in draws as the permitted work passes inspection. Lenders usually want the permitted plan set and a builder contract before they commit.

On a lot in a special flood hazard area (SFHA), any federally regulated lender will require flood insurance on the ADU; the flood section below covers the rules.

An ADU permitted in Jacksonville today is designed to the Florida Building Code 8th Edition (2023), which references ASCE 7-22 and applies to permits submitted on or after January 1, 2024. The 9th Edition takes effect December 31, 2026, so a permit filed before then stays on the current edition.

Wind speed depends on which side of the Duval demarcation line your lot sits. Under Municode Sec. 320.402, the ultimate design wind speed for Risk Category II is 125 mph west of the line and 130 mph east of it. The line runs up the center of the St. Johns River from the south county line to the Fuller Warren Bridge at I-95, then north along I-95 to the county line. A 2007 Duval wind map showing 105–119 mph lines still circulates in cost guides; it is superseded.

Your plans must state wind speed, exposure category and risk category on the coversheet, along with component and cladding pressures. Exposure B applies where Surface Roughness B extends at least 1,500 ft upwind for a mean roof height of 30 ft or less; Exposure D applies within 600 ft of open terrain or water extending at least 5,000 ft upwind. Exposure C covers everything else. Open riverfront and coastal lots land in D, which raises design pressures.

East Duval's 130 mph speed is also the threshold for the Wind-Borne Debris Region. The 8th Edition reverted to the ASCE 7-16 definition, designating the WBDR as coastal locations in 130–139 mph regions, with "mean high water" left to the local authority. Duval publishes no WBDR map, so coastal and Beaches-adjacent parcels are the ones to confirm with the Building Inspection Division. Inside the WBDR, glazed openings must be impact-resistant or covered (large-missile tested within 30 ft of grade), and every window and shutter needs a COJ-PAIS product approval sheet under F.S. 553.842.

The structural requirements follow the 2023 FBC-Residential:

• R301.1 requires a complete load path from roof to foundation.
• R301.2.1.1 requires wind design by AWC WFCM, ICC 600, ASCE 7, AISI S230, FBC-Building or the MAF Guide wherever the speed reaches 115 mph; the MAF Guide only reaches 130 mph in Exposure B and 110 mph in Exposure C.
• R802.11 requires truss connections capable of resisting the uplift on the truss design drawings.
• R803.2.3.1 sets roof sheathing nail schedules by wind speed, and R905.2.6.1 requires asphalt shingles to meet ASTM D3161, TAS 107 or ASTM D7158 classes for the design speed.

Jacksonville requires structural plans digitally signed and sealed under F.S. 471.025 and 481.221, and the truss package must be sealed and approved by the Engineer of Record. Two statutory relief valves exist: F.S. 481.229 exempts plans for one- and two-family residences and domestic outbuildings from the architect requirement, and F.S. 553.79 allows contractor certification to substitute for sealed plans in the wind-resistance review of one- and two-family dwellings. Modular units built on or after March 1, 2002 must already comply with the FBC, which leaves the foundation and anchoring as the local engineering items.

You can rent your Jacksonville ADU on a long-term lease once it has a certificate of occupancy, but you cannot rent both the ADU and the main house. The Times-Union reported that the owner must live in either the primary residence or the ADU, and the ordinance's homestead condition reinforces that by tying the unit to an owner-occupied parcel. For a portfolio investor, that rules out the two-rental-units play on a single lot unless Ordinance 2024-0870-E's homestead change is confirmed, and even then the owner-lives-on-site rule stands as reported.

Short-term rentals add DBPR licensing and tax obligations. A rented ADU also needs insurance that covers its actual long-term or short-term use.

Long-term lease vs. short-term rental

Short stays are where the rules get thin. The Times-Union reported on the enacted bill that ADU rentals are allowed "but not for fewer than 7 days," on the reasoning that existing regulations already bar rentals shorter than a week citywide. The 7-day rule does not appear in the zoning code text, and a 2019 Daily Record piece quoted the City as saying the zoning code does not specifically address short-term vacation rentals, which are allowed in residential areas as a "dwelling unit." Jacksonville has no STR registration or licensing ordinance; Ordinance 2019-238 would have created one and failed. The Tourist Development Council recommended a framework in September 2024 that has not been enacted. It proposed a 30-day minimum stay when the owner lives elsewhere and 14 days when the owner lives on site, along with occupancy, parking and licensing rules.

The state caps what the City could do anyway. F.S. 509.032(7)(b) bars any local law adopted after June 1, 2011 from prohibiting vacation rentals or regulating their duration or frequency. SB 48 (2026), which would have barred cities from prohibiting ADU rentals except for terms under one month, passed the Senate 38-0 and died in the House on March 13, 2026.

Whether to run an ADU as a short-term rental is a smaller question than it looks: Housing Action Lab found only 3% of about 1,400 permitted ADUs across six liberalized Florida jurisdictions host an active STR listing.

DBPR license and taxes under 30 days

Renting the whole ADU more than three times a year for stays under 30 days, or advertising it as regularly rented that way, requires the owner to obtain a DBPR Division of Hotels and Restaurants vacation-rental license under F.S. 509.242. You apply on form HR-7028 for a Vacation Rental–Dwelling license. The DBPR fee schedule lists a $50 application fee and a $10 HEP fee. A one-unit single license costs $170, or $90 for a half year. District 5, which covers Jacksonville, renews on June 1 and December 1. Vacation rentals skip the opening inspection but must be available to the Division on request. Operating without a license is a second-degree misdemeanor with fines up to $1,000 per offense.

Taxes on short stays stack to 13.5%. Duval's 6% Convention/Tourist Development Tax applies to rentals of six months or less, on top of the 6% state sales tax and the 1.5% Duval discretionary surtax for 2026. The Duval Tax Collector states there is "no agreement between Duval County and any online rental platform (e.g., Airbnb, Vrbo) to collect or remit this tax," so you register (231 E. Forsyth St., Room 212; touristtax@coj.net; 904-255-5700) and file monthly returns even for zero-activity months, due the 1st and delinquent after the 20th. State registration uses Form DR-1 and reporting uses Form DR-15.

Insuring a rented ADU

Once a tenant moves into the ADU, check whether the homeowners policy on the main house covers a rented second structure or whether the unit needs its own landlord insurance. Allstate, State Farm, Farmers, Liberty Mutual, Nationwide, Travelers and GEICO do not list ADUs as a covered property type in their landlord products, and Erie does not write in Florida at all. Steadily covers ADUs and short-term rentals (Airbnb and VRBO) in all 50 states under the same landlord platform that writes DP1, DP2 and DP3 forms for long-term leases, with liability options from $100K to $1M+ and loss of rental income up to 12 months of fair rental value. Flood is excluded from every form, which matters on a lot in a FEMA special flood hazard area (SFHA); the flood section below covers that separately.

Pricing follows exposure. Steadily's national average landlord premium is about $1,478 a year, while hurricane-prone Florida properties average roughly $9,462. See ADU insurance for coverage details, and the guides to landlord insurance in Jacksonville and landlord insurance in Florida for local pricing. Get a quote in minutes at quote.steadily.com, no phone call required; quotes auto-populate construction data from public records, and policies can bind within minutes.

Three constraints can stop a zoning-compliant ADU before it reaches plan review. An HOA covenant can stop the project because the City will not override it. A locally designated historic district requires a Certificate of Appropriateness, while a FEMA special flood hazard area forces the lowest floor to BFE + 2 ft. Check all three against the parcel before you pay for drawings.

HOA and deed restrictions

Florida has no statute that voids HOA covenants banning ADUs. F.S. 163.31771 contains no covenant-preemption language, nor do the 2023–2026 ADU bills, which sets Florida apart from California (Civil Code s. 4751) and Washington (RCW 64.38.160). The Times-Union put the local position plainly: "the city's allowance of ADUs does not overtake existing neighborhood rules, meaning if an HOA says they are not allowed then they are not," and the permit application makes you certify whether the ADU is permitted under your deed restrictions.

If your declaration does not ban second structures outright, the association still controls architectural review. Under F.S. 720.3035, an HOA may review "location, size, type, or appearance" only when that authority is "specifically stated or reasonably inferred" in the declaration or published guidelines, must apply its standards "reasonably and equitably," and must cite the specific rule and nonconforming aspect in any denial. Owners can recover damages and fees when an association "unreasonably, knowingly, and willfully" infringes. HB 803 (Ch. 2026-63, effective July 1, 2026) bars an association from demanding a building permit before it conducts certain reviews, so City approval and HOA approval run on separate tracks.

Florida courts have enforced shed and detached-building covenants and apply the reasonableness test from Hidden Harbour Estates v. Norman (1975). No Florida appellate decision addresses an ADU by name. Under F.S. 720.305, fines run up to $100 per violation or $1,000 aggregate unless the documents say otherwise, after a hearing before a committee of at least three non-officer members.

Amending a declaration to allow ADUs takes two-thirds of voting interests under F.S. 720.306. A dispute over parcel use requires a presuit mediation demand under F.S. 720.311 before anyone can sue: 20 days to respond, a conference within 90 days, and costs split equally.

Historic districts and overlays

The 2024 COA guide requires a Certificate of Appropriateness for any exterior change in Springfield and Riverside Avondale. Saint Johns Quarter is also covered, "regardless of its street visibility." The 2026 COA matrix sends a new accessory structure through staff-level administrative review only if it sits in a traditional location, matches the primary structure's design, and is one story under 576 sq ft. Two stories, more than 576 sq ft, a non-traditional location, or an incompatible design goes to the Jacksonville Historic Preservation Commission. A COA is valid for one year, or five years once work begins.

The design guidelines are specific. Riverside/Avondale wants garages at the back of the lot and subordinate to the house, with wood siding and one-over-one windows predominating, and it prohibits plywood and unpainted block on infill. The New Construction Supplement calls for simple gable or hip roofs that mirror the main house's features without exceeding its massing. The May 2024 Window Supplement requires new-construction windows recessed 1–4 inches.

Overlays add their own rules. The Riverside/Avondale overlay (Sec. 656.399.29) allows a one-foot side and rear setback measured from the eave and gutter, prohibits front-yard parking, and states that "the owner of the principal structure with a garage apartment must reside on the property." The Springfield overlay repeats the 25%/750 sq ft cap and requires the unit within 50 ft of the rear line and not forward of the front plane. San Marco's riverfront rear yards (Sec. 656.399.8) prohibit accessory living quarters entirely; the only allowance is a 150 sq ft, 15 ft accessory structure by administrative deviation.

FEMA flood zones

FEMA treats a habitable ADU as a residential structure, not an accessory structure, so a flood-zone lot pulls the unit into full residential floodplain rules. The effective Duval County FIRM dates to November 2, 2018; FEMA issued preliminary replacement maps on May 29, 2025, and the new panels take effect six months after a Letter of Final Determination that has not been issued.

Jacksonville's local amendments in Sec. 321.109 exceed the state baseline:

• In A, AE and Coastal A zones, the lowest floor must sit at BFE + 2 ft or the design flood elevation, whichever is higher, against the state's +1 ft.
• AO zones require the FIRM depth plus 2 ft, or 4 ft where no depth is specified.
• V and Coastal A zones require the bottom of the lowest horizontal structural member at BFE + 2 ft, foundations on pilings or columns with an obstruction-free space or breakaway walls below, and no basements or structural fill.
• Any enclosure below the required elevation is limited to parking, access or storage and needs flood openings of at least 1 sq in per sq ft of enclosed area, on at least two sides, with the bottom of each opening within 1 ft of grade.
• Mechanical, plumbing and electrical systems must sit above the DFE except minimum life-safety electric service.

In any zone other than X you file two FEMA elevation certificates, one before the slab inspection and one at final. A garage conversion runs into the substantial-improvement test: when the project value reaches 50% of the existing building's value, the entire building, not just the converted space, must be brought to current elevation standards. FEMA P-758 excludes detached garages from that calculation; confirm with floodplain staff how that applies to a conversion.

When a lender finances property inside an SFHA, federal rules require the lender to make the owner carry flood insurance. The exemption for detached structures that do not "serve as a residence" does not reach a unit with sleeping, bathroom or kitchen facilities.

An NFIP Dwelling Form insures one building, so a house and a rented ADU need two policies. Each policy is capped at $250,000 in building coverage under the Regular Program.

Citizens Property Insurance policyholders with wind coverage in zones A, AO, AH, AE, V or VE must carry flood coverage on all policies from January 1, 2027. Jacksonville's Community Rating System Class 6 standing earns a 20% NFIP discount inside the SFHA and 10% outside it.

The Duval County Property Appraiser adds a finished ADU to your parcel at market value in the first year after it is substantially complete, and that value sits on top of your Save Our Homes capped base without resetting it. The PAO's own language is that "additions/improvements are assessed at market value in the year constructed and then added to the capped base," which matches F.S. 193.155(4)(a). After that first year the combined assessed value grows no faster than 3% or the CPI change, whichever is lower.

Timing is set by the January 1 rule in F.S. 192.042. Work that is substantially complete by January 1 goes on that year's roll; anything finished later waits for the next year. The appraiser does not rely on you to report it: the Field Operations Division receives a daily list of issued City permits (and monthly lists from the Beaches and Baldwin), screens for value-altering work, and inspects before adding the change to the upcoming roll.

Renting the ADU raises a separate question about the exemption itself. The Duval Property Appraiser's AirBnB brochure, which the office now supplies on request rather than online (see the exemptions page, which lists it under brochures available by phone or email), says renting your home on January 1 ends the homestead exemption and the Save Our Homes cap, renting for more than 30 days in two consecutive years after January 1 makes you ineligible, and renting all or substantially all of the home is abandonment. You must notify the appraiser by March 1 if the property stopped qualifying as of January 1; failure can mean back taxes for up to ten years plus 50% penalties and 15% interest.

A rented ADU on an owner-occupied parcel is a portion question, not an abandonment question. F.S. 196.031(4) limits the exemption to "the portion of property so classified and assessed" as owner-occupied, and in Rebholz v. Department of Revenue (Fla. 2023) the Florida Supreme Court held that where a tenant has exclusive use of part of a property, that portion is not the owner's residence, while the appraiser left the exemption intact on the owner-occupied portion. That supports keeping homestead on the house while the ADU is assessed as rental, but no Duval PAO guidance specific to ADUs exists, and SB 48's proposal to assess a rented ADU "separately … and taxed according to its use" died with the bill.

If the ADU houses a parent or grandparent aged 62 or older instead of a tenant, F.S. 193.703 lets the county exclude the construction-driven increase in assessed value up to the lesser of that increase or 20% of the total assessed value, on an annual application filed before March 1.

Ordinance 2022-448-E stops at the Beaches boundary, and each of the three beach cities writes its own ADU rules. Jacksonville Beach is the most restrictive, Atlantic Beach permits a "garage apartment" on a narrow set of lots, and Neptune Beach has no ADU-specific provision in its published code:

Atlantic Beach is the best documented of the three, with its garage-apartment rule in Municode (Sec. 24-151(j), Ordinance 90-24-253, effective October 14, 2024). Detached garages there are capped at 600 sq ft and their living space cannot be rented at all, so the 75% figure applies only to a true garage apartment on a qualifying double-frontage lot.

Jacksonville Beach's standards in Sec. 34-558(a) come from a third-party Zoneomics transcription, and the city scheduled Ordinance 2025-8220, a full repeal-and-replace of Chapter 34, for second reading on February 18, 2025. Confirm the final vote with the city; until then, the 350–500 sq ft range and the affidavit rule are unconfirmed against live code. Jacksonville Beach also requires a Short-Term Vacation Rental Certificate renewed annually by October 1, a local layer Jacksonville itself does not have.

Neptune Beach's figures are general accessory-structure standards that may or may not govern a habitable unit. Ordinance 2023-10 amended Sec. 27-332 and added 27-335 and 27-336 in October 2023, and the city has not posted operative text online; ask the Neptune Beach planning staff directly before assuming anything.

These answers summarize the qualification, cost, occupancy, rental, permitting, and property constraints covered above.

What qualifies as an ADU in Florida?

Under F.S. 163.31771(2)(a), an ADU is a secondary living unit with its own kitchen, bathroom and sleeping area, either inside the primary structure or on the same lot. The statute only authorizes cities to permit ADUs; it does not require them to, and the 2025 and 2026 bills that would have mandated by-right ADU ordinances (SB 184, HB 247, SB 48, HB 313) all died.

What is the cheapest ADU option in Jacksonville?

A garage conversion is the cheapest option in Jacksonville, FL: vendor estimates place it at $55,000–$145,000 against $120,000 and up for a detached unit. Advertised floors of $70,000–$85,000 for studios and tiny homes are marketing starting points, not finished-project costs.

What is one drawback of building an ADU in Jacksonville?

The biggest drawback is the owner-occupancy rule. You cannot rent the house and the ADU at the same time, so a single lot cannot become two income units while that rule stands, and renting too much of the parcel puts the homestead exemption and Save Our Homes cap at risk.

Is owner occupancy required for a Jacksonville ADU?

Yes under the enacted 2022 text, which ties the ADU to a parcel with an existing or pending homestead exemption. The Times-Union reported that the owner must live in either structure. Ordinance 2024-0870-E may have removed the homestead condition, but its enactment and final text are unconfirmed.

Can I put my Jacksonville ADU on Airbnb?

Stays of a week or more are reported as allowed, and Jacksonville has no STR registration or licensing ordinance. If you rent the unit more than three times a year for stays under 30 days, DBPR requires a vacation rental license. The fees are $50 for the application, $10 for HEP, and $170 for a one-unit license. You must also remit the combined 13.5% sales-tax-plus-tourist-tax burden yourself.

How long does JaxEPICS review take and what does it cost?

The published first-review service level is 25–30 business days, with resubmittals in about 10, though the City reported 8-day residential averages in 2025. New-building permit fees run $6.38 BID, $1.60 resource management and $2.13 Development Services per 100 sq ft, plus $8.75 per 100 sq ft for C&D debris and a $112.50 minimum BID fee; conversions pay $3.00 per $1,000 of job cost.

Can an HOA, historic district, or flood zone block my ADU?

Yes. The City defers to HOA covenants. Springfield and Riverside Avondale require a Certificate of Appropriateness, as does Saint Johns Quarter, with Commission review for anything over 576 sq ft or two stories. A special flood hazard area forces the lowest floor to BFE + 2 ft and requires flood insurance on any lender-financed unit.