How to Check if Your Central Florida Lot Can Accommodate an ADU

Before you talk to a builder, before you price out a loan, before you draw anything on a napkin — you need to know whether an ADU is legally buildable on your specific parcel. The answer is a function of several things: your jurisdiction, your zoning district, your lot’s dimensions, what structures are already on it, and what private restrictions are recorded against your deed. This guide walks you through how to answer each one in about an hour using free public tools.

What you need: your property’s parcel ID or address, a browser, and about an hour. No sign-up, no address form, no one following up to sell you something.

Step 1: Pull your parcel record and confirm your jurisdiction

Every county in Central Florida has a property appraiser with an online parcel search. Go to the right one for your county:

• Orange: ocpafl.org
• Seminole: scpafl.org
• Osceola: property-appraiser.org
• Lake: lakecopropappr.com
• Polk: polkpa.org
• Volusia: vcpa.vcgov.org
• Brevard: bcpao.us
• Marion: pa.marioncountyfl.org
• Sumter: sumterpa.com

Search by address or owner name. Write down four things from the result:

1. Total lot area in square feet or acres.

2. Your zoning district code (e.g., R-1AA, R-1, A-1, PUD, RA-2). This is the most important field on the page.

3. Your municipality. Look for a field labeled “Municipality,” “City,” or “Taxing District.” If it shows a city name — Orlando, Kissimmee, Sanford, Lakeland, Apopka, Winter Park — your project is governed by that city’s Land Development Code, not the county’s. A Kissimmee mailing address does not mean you are under Kissimmee’s code; a Kissimmee municipality designation does. If you are inside an incorporated city, see that city’s page on this site before proceeding with county-level rules.

4. Your Future Land Use (FLU) designation. This is separate from your zoning code and represents the county’s long-range plan for your parcel. A parcel currently zoned R-1 but FLU-designated as “Medium Density Residential” or “Commercial” may be on a path toward rezoning. That doesn’t block your ADU today, but it does affect how you should think about the investment. More immediately: some counties require that proposed improvements be consistent with both the current zoning and the FLU designation. If the two are already inconsistent (a “split designation”), flag this in your pre-application meeting with the planning division.

Also note any overlay districts. A historic preservation overlay, a wellhead protection overlay, a special flood hazard overlay, or a tourism corridor overlay can all change the rules materially — sometimes making ADUs harder to permit, sometimes creating additional relief pathways.

Step 2: Check for HOA covenants and deed restrictions

Do this before any dimensional analysis. HOA covenants and deed restrictions are private contracts recorded against your property, and they override zoning permissions. A parcel in a perfectly ADU-eligible zoning district can still be covenant-prohibited from adding any accessory structure. Finding this out after you’ve spent money on drawings is expensive. Finding it out in ten minutes at your computer is free.

How to find your covenants: Go to your county’s Clerk of Courts official records portal and search by your parcel ID or owner name. Look for any recorded document with “Declaration,” “Covenants,” “Restrictions,” or “CC&R” in the title. The Declarations of Covenants, Conditions, and Restrictions (CC&Rs) are the document you want. They are typically filed at the time a subdivision is platted and run with the land indefinitely unless formally released.

County clerk official records portals:

• Orange: myorangeclerk.com
• Seminole: seminoleclerk.org
• Osceola: osceolaclerk.com
• Lake: lakecountyclerk.org
• Polk: polkcountyclerk.net
• Volusia: clerk.org
• Brevard: brevardclerk.us
• Marion: marionclerk.com
• Sumter: sumterclerk.com

In the CC&Rs, search for language in Articles IV or V covering “accessory structures,” “outbuildings,” “guest houses,” “second dwellings,” or “residential use.” If the covenants prohibit accessory structures or limit each lot to one dwelling unit, the zoning code is irrelevant to your project until you get a formal written exception from the HOA board — which many boards will not grant.

If you already have CC&Rs from your closing package, pull those. If they are more than five years old, also check the clerk’s portal for any recorded amendments.

If there are no covenants, or covenants that do not restrict accessory structures: continue to Step 3.

Step 3: Check the minimum lot size against your zoning district

Each county code sets a minimum lot size for an ADU in each zoning district. In most of the Central Florida counties we cover, the requirement is stated one of three ways: a minimum gross lot area (e.g., 6,000 sq ft in R-1); a minimum lot area per dwelling unit with the ADU counted as a unit; or a minimum lot size that is simply “as required in the underlying district.” The county pages on this site summarize the rules for each jurisdiction — start with your county page for the number that applies to you.

If your lot is at or above the minimum for your district, move on. If your lot is below the minimum — it happens, especially on older plats from the 1950s and ’60s — you may still be buildable under a nonconforming-lot provision. Call the county planning division directly to confirm. Most counties have staff who will answer this specific question over the phone in a few minutes.

Step 4: Locate the setback lines on your lot

This is the step that kills more ADU projects than any other. Your usable buildable area is not your lot. It is your lot minus the front, side, and rear setbacks required by your zoning district minus any easements recorded on the plat minus your existing primary structure and any existing accessory structures minus the required separation between structures.

Pull out your survey. The surveyor will have drawn your property boundaries and, usually, the building setback lines as dashed lines inside the boundary. If your survey does not show setback lines, get your zoning district’s setback table from your county code — the setbacks section on your county page here is a starting point — and measure them yourself from the property lines. Front setbacks in Central Florida residential districts typically run 20–30 feet; side setbacks run 5–10 feet; rear setbacks run 7.5–25 feet. ADUs frequently have different (often smaller) setbacks than the primary structure — check your specific district.

Then look at easements. Your plat will show utility easements along the side and rear lot lines, typically 5–10 feet wide. You cannot build in an easement. A drainage easement across the rear of the lot can erase your ADU option entirely.

Mark everything the ADU cannot sit on: setbacks, easements, the primary structure footprint, the minimum required separation (usually 10 feet, sometimes 6) from the primary structure, the septic tank and drainfield if you are on septic, the well and its required radius if you are on a well, any large trees that are regulated under the county’s tree protection ordinance.

What is left is your buildable envelope. If it is big enough to fit a 20×30 ft footprint (600 sq ft) or whatever size ADU you are planning plus code-required access, you are in. If it is not, you either shrink the ADU, move it (attached or interior conversion instead of detached), or stop here.

Step 5: Measure the ADU size you are allowed

Most Central Florida counties cap ADU size as a function of either the primary dwelling or the lot. Common formulations include: maximum 750 sq ft or 50% of the primary dwelling, whichever is less (common in Orange and several others); maximum 800–1,000 sq ft regardless of primary size; no explicit cap as long as the ADU remains subordinate to the primary (Marion). Check your county page for the specific rule in your jurisdiction.

Then check whether the rule is gross or net square footage. Some counties measure to the exterior wall; others exclude porches, stairs, or garages. If the ordinance is silent, the building department will use their administrative interpretation, which you can ask for in writing.

Step 6: Consider height, lot coverage, and impervious surface

Three other dimensional rules commonly constrain ADU design:

Height limit. Most Central Florida residential districts cap accessory structures at 25 feet or the height of the primary dwelling, whichever is less. A two-story ADU on a 22-foot primary dwelling is not legal unless you first vary the primary height.

Lot coverage. The ratio of all structures (primary + ADU + any garage or shed) to total lot area, usually capped at 30–50% in residential districts. If you already have a 2,200 sq ft house plus a 400 sq ft garage on a 6,000 sq ft lot, you are at 43% coverage before you add anything. A 600 sq ft ADU would push you over 50%. Do this math.

Impervious surface. The ratio of all surfaces that do not absorb water (roofs, patios, driveways, pools) to total lot area, usually capped around 60–70%. An ADU plus a required parking pad can tip you over. A pervious pavement driveway solves this in most counties; confirm before designing.

Step 7: Check your FEMA flood zone

This step is overlooked on more ADU projects in Central Florida than almost anything else, and it can be the most expensive surprise.

Go to the FEMA Map Service Center and enter your address. Your parcel will fall into one of these flood zone designations:

• Zone X (shaded or unshaded): Minimal flood risk. No special FEMA restrictions on your ADU project.
• Zone AE, AH, A1–A30, AO: You are in the 100-year Special Flood Hazard Area (SFHA). FEMA’s National Flood Insurance Program rules apply to new construction and — critically — to “substantial improvements.”
• Zone VE: Coastal high-hazard area. Most restrictive designation; common in coastal Brevard and Volusia.

Why this matters for ADUs: FEMA’s “substantial improvement” rule states that if the total cost of improvements to a structure over a rolling period (typically 5–10 years, varies by local ordinance) exceeds 50% of the structure’s pre-improvement fair market value, the entire structure — not just the ADU — must be brought into compliance with current floodplain management standards. For an older home in a flood zone, that can mean elevating the primary structure, which can cost more than the ADU itself.

The practical check: if your parcel is in Zone AE or VE, ask your county’s floodplain administrator (usually in the building or planning division) for the current substantial improvement threshold and the cumulative improvement tracking period before you budget anything. Several Central Florida counties — Orange, Lake, Osceola, and parts of Volusia — have local floodplain ordinances that are stricter than FEMA’s baseline. Your county’s locally adopted Flood Damage Prevention Ordinance (FDPO) is the governing document, not just the FIRM map.

Step 8: Verify utility service capacity

An ADU needs water, sewer (or septic), and electrical service. Check:

Water. If you are on a city or county utility, confirm there is capacity at your meter and line. Most of Central Florida is fine for a single ADU, but a few older neighborhoods on 1-inch mains may require an upgrade. If you are on a well, confirm the well can sustain the additional demand — your well driller or pump contractor can test.

Sewer. If you are on public sewer, the service lateral from your house connects to the main at the street or rear easement. An ADU needs either its own lateral or a branch off the primary’s lateral; either way, the connection fee (often thousands of dollars) applies. If you are on septic, this is the hardest question on the lot. Florida requires a permit from the Florida Department of Health’s Onsite Sewage Program to add a bedroom or bathroom served by an existing system. The drainfield may need to be expanded or replaced, adding $8,000–$25,000 to the project. A soil evaluation by a licensed septic contractor is the only way to know.

Electrical. Confirm your main service panel has capacity for the additional load, or plan to upgrade it. A 600 sq ft ADU with standard appliances and a mini-split typically needs a 100-amp subpanel. Most 1970s-era 100-amp main panels cannot support this without an upgrade to 200 amps. A licensed electrician can load-calculate your existing service in an hour.

Step 9: Talk to the planning division

With your numbers written down — lot area, zoning district, buildable envelope, proposed ADU size, utility plan, flood zone status — call the county planning division and ask for a pre-application conversation. Most Central Florida counties will answer initial questions over the phone or in a brief walk-in meeting at no charge. Bring your notes. Ask three specific questions: (1) does my lot meet the minimum for an ADU in my district, (2) are there any overlays or restrictions I have missed, (3) does the county require a survey to submit the permit application (almost always yes, but confirm). The planner will often flag something you missed — an unrecorded easement, a tree covenant, a prior variance on the parcel that limits further development.

Step 10: Commission a current survey if you are proceeding

If you are continuing to design, you need a current boundary and topographic survey from a Florida-licensed surveyor. Typical cost in Central Florida is $600–$1,800 for a residential lot, depending on lot size and vegetation. The survey will give you precise property lines (corrected if the plat has drifted), easement locations, existing structure locations to the inch, elevation contours, and — if you pay a bit more — septic and well locations. Your builder and engineer both need this. Do not skip it; a design based on a decades-old survey is how ADUs get built three feet over a property line.

What this check does not tell you

This guide tells you whether an ADU will physically fit and whether the zoning code allows it in theory. It does not tell you whether a pending amendment to your county’s code might change the rules, whether your mortgage has an owner-occupancy clause that complicates rental use, or whether your homeowner’s insurance carrier will renew once the ADU is built (several Florida carriers have quietly tightened on parcels with separate dwelling units). Each of these is an independent check.

Once you have completed this zoning check, you are ready to move on to the money side: what it will cost (our costs pillar has the breakdown for Central Florida) and how to finance it (our financing pillar covers the routes). And once you are ready to price the build, you will need to find and vet builders — that starts with the builders overview and the contractor license verification guide.