What Does It Cost to Own an ADU After It's Built?
Everyone online tells you what an ADU costs to build. Almost nobody tells you what it costs to own once it's built. Here's what actually changes on your bills after the ADU is finished, and what doesn't.
UTILITIES: DOES THE ADU NEED ITS OWN METER?
In St. Petersburg, a separate electric meter and mailing address for the ADU is optional, not required you can run it off your existing meter. For Pinellas and Hillsborough County properties, we confirm your specific utility provider's metering requirement (Duke Energy Florida or TECO) as part of your feasibility review, since policy depends on your provider and unit configuration.
What we can say with real numbers: Duke Energy Florida's residential rate has been running roughly 14-16.6 cents per kWh through 2026, with a rate reduction announced for later this year. TECO's residential rate has been running roughly 13-18 cents per kWh, with a typical 1,000 kWh household bill around $150-177 a month. How much an ADU adds to your bill depends entirely on how it's used, so we'll walk through a realistic range for your specific plans rather than quote a generic number.
PROPERTY TAXES: WHAT ACTUALLY HAPPENS TO YOUR BILL?
Florida assesses a new ADU at full market value...
We haven't confirmed whether Hillsborough County...
Sources
INSURANCE: THE PART MOST OWNERS GET WRONG
If You Rent
If you are renting the ADU, you must notify your insurance company. Standard homeowner policies do not always cover liability or damages caused by long-term or short-term (Airbnb) tenants.
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You may need a landlord policy or a specific rental endorsement.
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Always require tenants to carry their own renter's insurance.
Many homeowners assume an ADU requires a completely separate insurance policy. Typically, an ADU is covered under your primary homeowner's insurance as an "Other Structure" (Coverage B).
10%
Standard Coverage B limit (often insufficient for a full ADU)
You will almost certainly need to increase your Coverage B limits, which will raise your premium. The exact amount depends on the ADU's replacement cost.
ONGOING MAINTENANCE
Like any structure, an ADU requires upkeep. Because it has its own HVAC, plumbing, and roof, you should budget for long-term maintenance.
$2,041
Avg. Annual Maintenance (Main House)
*Angi's National Benchmark
$1,143
Avg. Annual Maintenance (ADU Estimate)
Based on smaller footprint
Why We Don't Give You a One-Size-Fits-All Number
Every property in Tampa Bay is unique. Your exact ongoing costs depend on several variables:
Your specific municipality: Tampa, St. Pete, Clearwater, and unincorporated areas all have different tax rates and utility fee structures.
Your insurance provider: Rates fluctuate wildly in Florida based on the ADU's construction type (block vs frame) and flood zone.
Intended use: Family guest house vs long-term rental vs short-term vacation rental.
Want to Know What Your ADU Could Cost to Own?
Get a feasibility review based on your property, utility setup, and ADU plans.