When you look at a Westerville home for sale, the annual property tax number attached to it belongs to the seller. It was calculated from the seller's value, the seller's levies and the seller's credits. For the bills Westerville owners will pay in 2027, that last piece is shifting under Ohio law. Two houses with identical 2026 values can get noticeably different bills depending on whether the owner lives there.
This lands in the same season as Franklin County's 2026 triennial property value update. The county's tentative figures show the average residential value in the Westerville City School District up 12%, compared with a countywide residential average of 10.1%. NBC4 reported the same gap in June, noting that Westerville outpaced the county's 10% average. The 12% is the number people will talk about. It is also the least useful number for predicting what a Westerville owner, or the next buyer, will pay.
Westerville Runs on Two County Calendars
Westerville sits in both Franklin and Delaware counties. Both are updating values for tax year 2026, with bills payable in 2027, but their review schedules differ.
| Franklin County | Delaware County | |
|---|---|---|
| Tentative values released | June 9, 2026 | Parcel-level proposed values posted online |
| How values are shown | Westerville CSD average: +11% all property, +12% residential | Parcel-by-parcel current and proposed values |
| Informal review | Sessions ended September 5; documents closed September 12 | Online submissions close October 30, 2026 |
| Final values expected | December 2026 | Mid-to-late December 2026 |
| Board of Revision complaints | Through March 31, 2027 | January 1 through March 31, 2027 |
For anyone reading this on Thursday, October 29, Delaware County's online informal review closes tomorrow. Its in-person residential appointments at the Byxbe Campus ran through October 22. Owners on the Franklin side can look up their tentative value and use a tax estimator on the auditor's Know Your Home Value site. Delaware County's 2026 triennial update page links to its proposed-value lookup.
Keep in mind that the 12% is a school district average for the Franklin portion. It is not a figure for the City of Westerville, and it says nothing about Westerville addresses in Delaware County.
A 12% Value Increase Is Not a 12% Tax Increase
Franklin County Auditor Michael Stinziano's office states it directly: "A property value increase does not result in the same percentage increase in property taxes." This follows from how Ohio treats voted levies. Under Ohio Revised Code section 319.301, rising values cannot increase the revenue a voted levy collects. When values go up, the effective rate goes down so that the levy raises the same total.
What changes is each property's share of that fixed total. The auditor's Misconceptions vs. Realities page gives three general rules:
- If your value rises by the same percentage as other properties with the same levies, your taxes from those levies stay the same, except for inside millage.
- If your value rises by less than that average, your taxes go down.
- If your value rises by more than that average, your taxes go up.
The benchmark is the group of properties that share the same levies, which is not the same as the school district average. A home whose value rose faster than that group's average takes on a bigger share of the voted levies, and a home that rose more slowly takes on a smaller one. For a buyer, a home's value change compared with properties that share its levies says more than the 12% headline does.
Inside Millage, the One Piece That Grows on Its Own, Now Has a Cap
Inside millage is the unvoted portion of the tax rate. It is the exception in rule one because it has not historically been reduced when values climb. HB 335, effective March 20, 2026, changes that for update years. County budget commissions must now adjust inside millage rates so revenue growth is generally held to cumulative inflation, measured by the GDP deflator over the prior three years. Growth from new construction and expiring tax reductions is excluded. The limit applies to tax year 2026, payable in 2027.
Delaware County Auditor George Kaitsa summed up the 2026 update in a January 16 statement: "Any increases in property taxes above the rate of inflation will be the result of levies passed by the voters in 2026." Delaware Source reported in May Kaitsa's view that the new law, together with tax-reduction factors, should prevent the kind of spikes owners saw after the 2023 reappraisal. Taxes can still go up when voters approve new levies.
With the value increase largely absorbed by levy math and the unvoted growth capped, the biggest change left for 2027 is the one tied to who lives in the house.
The Credit Moves From Rental Homes to Owner-Occupied Homes
For years, Ohio has applied two credits, or "rollbacks," to residential tax bills. One is a 10% nonbusiness credit for one-, two- and three-family homes. The other is a 2.5% owner-occupancy credit for a home that serves as the owner's primary residence. HB 186, effective March 20, 2026, phases out the nonbusiness credit for residential property and raises the owner-occupancy credit at the same time.
According to the Legislative Service Commission's analysis of HB 186, the combined effect raises the total credit for owner-occupied homes from 12.5% to 15.38% and eliminates the credit for residential property that is rented out or is not the owner's primary residence. The totals below add up the two published schedules:
| Tax year (payable) | Nonbusiness credit | Owner-occupancy credit | Owner-occupied total | Rental or non-primary home |
|---|---|---|---|---|
| Before HB 186 | 10% | 2.5% | 12.5% | 10% |
| 2026 (2027) | 7.5% | 5.70% | 13.2% | 7.5% |
| 2027 (2028) | 5% | 8.92% | 13.92% | 5% |
| 2028 (2029) | 2.5% | 12.15% | 14.65% | 2.5% |
| 2029 (2030) | 0% | 15.38% | 15.38% | 0% |
Nontimber agricultural land keeps the full 10% nonbusiness credit. These changes come from state law and apply in Franklin and Delaware counties alike.
There is a limit on how far these percentages reach. Franklin County says the owner-occupancy credit applies only to levies passed during or before the November 2013 general election. The LSC analysis adds that new and replacement levies approved at elections in or after November 2013 are excluded when either rollback is calculated. That means the credit percentages in the table apply to only part of a Westerville tax bill.
What This Means When a Westerville Home Changes Hands
This is where the 2027 bill becomes a transaction issue. Franklin County's Tax Reduction Programs page says the owner-occupancy credit requires the homeowner to own and occupy the home as their primary domicile as of January 1 of the tax year they apply for. The application form is the DTE 105C.
That leads to three things a Westerville buyer will run into:
- A home sold by an owner-occupant shows a tax figure that includes credits tied to that seller's occupancy, which is a status and an application, not a feature of the house.
- A home sold by an investor shows a figure with no owner-occupancy credit. Starting with 2026 bills, its nonbusiness credit is 7.5%, down from 10%.
- A buyer purchasing a home to rent out loses another 2.5 points of credit each year through 2029, when it reaches zero, while the owner-occupant next door gains ground.
The same reasoning applies to small investors already holding Westerville rentals. On those properties, the credit schedule will change the 2027 through 2030 bills more than the 2026 value notice will. For move-up sellers who plan to keep their current home as a rental, that home's tax treatment changes once it is no longer their primary residence.
This post is general information, not legal, tax or financial advice. Please confirm how these rules apply to your property with the county auditor, a tax professional or an attorney.
Questions Westerville Owners Are Asking
When will final 2026 values be known? Franklin County expects to finalize values in December 2026 after review by the Ohio Department of Taxation. Delaware County expects final certified values online in mid-to-late December.
What if I disagree with my final value? Both counties accept Board of Revision complaints on the 2026 value through March 31, 2027. Delaware County's window opens January 1, 2027.
Does the Westerville City School District 12% figure apply to my house? It is a preliminary average for residential property in the Franklin County portion of the district. Your parcel's tentative or proposed value is on your county auditor's lookup site.
If you're weighing a Westerville purchase, a sale, or turning your current home into a rental, the Linda Rano Jonard Team can go through the tax history on the homes you're comparing and explain what the numbers reflect, so you know which tax figure applies to you before you make an offer. Request a Free Home Valuation & Consultation, and we'll start with your address and both county calendars.
