Before One Wall Goes Up: What Orlando ADU Permits and Plan Review Actually Cost

Where the sixty-thousand-dollar number actually comes from

It comes from building a house. Not a backyard unit.

If you put up a brand-new single-family home in unincorporated Orange County, the county collects before you get keys. School impact fee on a house under 2,000 square feet is $8,829. Transportation runs into five figures depending on size and whether you're urban or rural. Parks, law enforcement, and fire pile on top. Nobody's lying when they say the government takes a big bite. They're just describing a different project than the one in your backyard.

Because buried in the county's impact fee assessment guide there's a small table with five rows, and it's the most useful thing on the whole page. Accessory dwelling unit, 1,500 square feet or less: exempt from law, exempt from fire, exempt from parks, exempt from transportation, exempt from school. Go over 1,500 square feet and law, fire, and parks come back at the single-family rate — but transportation and school stay exempt either way. The two biggest line items on that list never apply to an ADU at all.

And this is why the rumor travels so well. Florida never passed a statewide ADU rule to flatten the differences. A bill that would have required every local government to allow them died in messages on March 13, 2026. So the answer really does change at the city line, which means everybody's horror story is true somewhere and useless everywhere else.

What the county charges to actually look at your drawings

Here's the part that surprises people who've been bracing for impact.

Orange County prices a one- and two-family building permit off construction valuation: $26 for the first thousand dollars, then $3 for every thousand after that. And the county sets a floor on valuation with its own table — wood-frame residential comes in at $97 a square foot. Run a 700-square-foot cottage through that and you land somewhere around $230 for the building permit. Zoning's residential plan review adds $34. The lot grading site plan review adds $38.

That's the permit. It costs less than a decent set of tires.

The money before construction is somewhere else entirely, and it's the part people skip right past. Orange County requires the construction plans for an ADU to be signed, sealed, and dated by a Florida licensed engineer or registered architect. You'll also need a survey, a lot grading and drainage plan showing finished floor elevation, a product approval specification sheet, and energy calcs if there's HVAC. That's a professional's invoice, not a fee schedule, and it's the real first check you write.

Then there's the one that catches people sideways: if your ADU needs a special exception through the Board of Zoning Adjustment, that's $1,355 just to be placed on an agenda. Nonrefundable. That single line is bigger than every permit and review fee on your project combined, and it comes due before anybody's measured anything.

Which is what makes Ready Set Orange worth a look. Orange County will hand you a pre-designed ADU plan set at no charge — the four floorplans are named after citrus, which is either charming or exactly what you'd expect, and they run from the 531-square-foot Clementine up through the Seville at 700 and a two-story Tangerine. It's for unincorporated Orange County only, the property has to be homesteaded, and both units have to stay under one owner. The county gives you the drawings. You still hire the licensed professional to finalize the set.

The bill that isn't a permit at all

Ask what the biggest pre-construction check is and most people guess the permit. It's usually the pipe.

Orange County Utilities charges a water capital charge of $2,790 per equivalent residential connection and a wastewater capital charge of $5,270 per equivalent residential unit. Those are capacity charges under Chapter 37, and they have nothing to do with your lot or your drawings. You're buying a seat at a treatment plant you'll never visit. Put together, that's more than thirty times what the county charges to review the plans.

If you're on septic — and plenty of Conway, Azalea Park, and Rio Pinar lots are — the fork goes the other way and gets more interesting. Adding a bedroom isn't a minor modification. Florida rates each bedroom at 100 gallons a day of design flow, so a one-bedroom cottage adds 100 gallons a day to whatever your existing system was permitted to handle. If your drainfield can't carry it, that's a health department question about a system modification, and it gets answered before the building department cares about your walls. Two identical backyards on the same street can produce wildly different numbers here purely based on what's buried in the yard.

The other thing worth checking before you budget anything: which government you actually live under. Pine Hills, Meadow Woods, Azalea Park, Conway, and Rio Pinar are unincorporated Orange County, so the county's rulebook and Ready Set Orange both apply. Winter Garden is its own city with its own code. And if you're inside Orlando city limits, you're reading a different book entirely — the city publishes its own averages, $450 to $1,050 for building permit fees and $1,300 to $3,100 for ADU impact fees, and in February 2026 the council approved an incentive program that rebates 100% of building permit fees, 100% of park, transportation, and sewer impact fees, plus up to $10,000 toward construction. The catch is a 500-square-foot cap and a commitment to rent to someone at or below 120% of area median income for 12 of the first 24 months after your certificate of occupancy.

Same metro. Same size cottage. A mailing address that says Orlando doesn't tell you which of those applies to you.

So what does your specific backyard cost to permit?

Nobody can answer that from a fee schedule, including this one. The fee schedule is the easy half.

The hard half is four questions about your particular lot. Are you inside a city or in unincorporated county. Is your property homesteaded and under single ownership. Are you on county sewer or on a septic system that may or may not have room for another hundred gallons a day. And does your zoning district hand you the ADU or make you go ask for it, because that's the difference between a thirty-four-dollar review and a thirteen-hundred-dollar hearing.

Answer those four and the pre-construction number stops being a rumor and starts being arithmetic.

That's what the ADU Fit Check is for. Tell us where the property is and what's under the yard, and we'll tell you which rulebook you're actually in, which fees your address triggers, and where the real money sits before a wall goes up. It takes a few minutes and it's the cheapest thing you'll do on this whole project.

Common questions

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