Building an accessory dwelling unit in Orlando in 2026 runs $185,000 to $360,000 for a detached, permitted, code-built unit. The spread is wide because Orlando ADUs sit on top of two cost drivers most cities never deal with: karst geology that can demand a geotechnical report and engineered foundations, and a humidity load that forces a properly sized, sealed HVAC system from day one.
The Honest 2026 Price for an ADU in Orlando
A detached 600 to 900 square foot ADU with a real kitchen, full bath, and its own HVAC lands between $185,000 and $360,000 once you include design, permits, site work, and utility connections. Garage conversions run lower, $95,000 to $150,000, because the shell already exists. The number people quote at the start is almost always the construction-only figure. The number you actually pay includes soft costs (design, survey, geotechnical, permits) that add 15 to 25 percent on top.
What Drives ADU Costs in Orlando
See what a ADU build actually costs in your Orlando zip.
Take 4 questions →Labor and Crew
Orlando's construction labor pool is stretched by tourism-driven commercial work and steady single-family demand. A licensed general contractor coordinating a detached ADU bills the work across framing, mechanical, electrical, and plumbing trades, and each trade carries its own permit and inspection. Expect crew costs to make up roughly 40 to 50 percent of the total.
Site Work and Foundation
This is where Orlando diverges from drier metros. Central Florida sits on karst limestone, so a geotechnical investigation is common before a foundation is poured. If borings find weak soils or a void, the design shifts to a deeper or engineered foundation, and that single line item can move the budget by $15,000 to $40,000. A clean lot with good soils keeps you near the low end.
HVAC and the Building Envelope
A 700 square foot unit in Orlando needs a sealed, dehumidified envelope, not a window unit. Right-sizing the system (a Manual J load calculation rather than a rule of thumb) prevents the short-cycling that leaves a humid unit feeling clammy and grows mold behind the drywall. Budget $8,000 to $14,000 for a heat pump system sized and sealed for the climate.
Orlando ADUs by Tier: 3 Real Project Examples
Tier 1, garage conversion ($95,000 to $150,000): An existing two-car garage in College Park converted to a one-bed unit. The shell stays, so the spend goes to insulation, a mini-split, a compact kitchen, and a code bathroom. Permits are simpler because no new foundation is involved.
Tier 2, detached studio ($185,000 to $260,000): A new 550 to 700 square foot detached unit in Baldwin Park on good soils. Standard slab foundation, a full kitchen, one bath, and a sealed heat pump. This is the most common Orlando ADU.
Tier 3, detached two-bed ($290,000 to $360,000): A 900 square foot two-bedroom in Winter Park where lot constraints, a geotechnical-driven engineered foundation, and higher finishes push the number up.
Permits and Local Code in Orlando
Orange County and City of Orlando Review
Orange County and the City of Orlando require permits for structural, roofing, electrical, plumbing, and mechanical work. Most residential permits issue in 2 to 6 weeks; plan review can extend that during hurricane-season backlogs. Florida product approval (NOA or Florida Product Approval number) is required for roofing assemblies and exterior openings.
Sinkhole Disclosure and Geotechnical Review
Florida law requires sellers to disclose known sinkhole activity, and lenders and insurers care about it. For an ADU, the practical impact is the geotechnical report: it protects you, your contractor, and your future resale. Skipping it to save a few thousand dollars is the most expensive shortcut in Central Florida construction.
The Orlando Neighborhoods Where ADU Costs Diverge
Winter Park and Baldwin Park
Mature tree canopy, tighter lots, and design-review expectations push both the build cost and the timeline. Tree-protection ordinances can dictate where the unit sits.
Lake Nona and East Orlando
Newer master-planned areas often carry HOA architectural review, which adds a design-approval step before the county will accept the permit set.
Timeline: Realistic Week-by-Week Expectations
Phase 1: Design and Permitting (8 to 16 weeks)
Survey, geotechnical, design, engineering, and plan review. Hurricane-season backlogs at the county can stretch the review window.
Phase 2: Active Construction (16 to 32 weeks)
Foundation, framing, dry-in before the rainy season if you can time it, then mechanical, electrical, plumbing, and finishes with inspections at each stage.
How to Vet an Orlando ADU Contractor
Key Questions to Ask
Ask for the Florida license number and verify it. Ask how they handle the geotechnical report and who carries the engineering. Ask for two recent detached-ADU references in Orange County, not just remodel work.
Red Flags to Watch For
A bid with no geotechnical line item on a detached unit, a window-unit HVAC plan, or a refusal to pull permits in the homeowner's jurisdiction. Any of these signals a build that will cost more later.
Renology Take
In Orlando the ADU budget is decided below grade and inside the wall: the foundation the soil demands, and the HVAC the humidity demands. Get the geotechnical report, size the system with a real load calculation, and the rest of the project behaves. Treat both as optional and Central Florida will collect the difference within two years.
Methodology
How Renology estimates adu / garage conversion costs in Orlando.
Renology treats this page as a planning benchmark for Orlando, Florida, not a final quote. We compare published local guide data, contractor scope patterns, permit-sensitive work, climate or site constraints, and finish-level assumptions.
Cost range
$185,000-360,000
Timeline
24-48 weeks
Source type
Editorial dataset
Local factor: Humid subtropical (Köppen Cfa): about 52 inches of rain a year, hot wet summers with daily afternoon storms, and high year-round humidity. Wind-borne-debris exposure and karst (sinkhole) geology shape both code and cost.
Use these numbers to shape a scope and spot missing line items. Confirm permits, structural work, electrical, plumbing, gas, waterproofing, drainage, and code-sensitive details with the local building department and a licensed professional.
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