Pull up two Galena listings side by side on any portal. Both sit inside 43021. Both show four bedrooms, three baths, roughly 2,900 square feet, both listed around $625,000. The photos look interchangeable. The commute times to Polaris are within a minute of each other.
The monthly payments are not interchangeable. On one of those homes, the property tax line on your closing disclosure will be roughly $8,000 a year higher than on the other. Same price, same size, same ZIP. Different school district.
The line most portal maps don't draw
Galena's 43021 straddles two Delaware County school districts. The southern and western portions of the ZIP fall inside Olentangy Local Schools. The northern and eastern portions, closer to Sunbury and along the SR-3 corridor, fall inside Big Walnut Local Schools. Some rural roads have the boundary running down the middle of them.
Portal search filters treat "Galena" as one market. The county tax bill does not. According to the Delaware County Auditor's published tax rate schedule, the Galena Corporation-Big Walnut taxing district totals roughly 65.5 mills, while the Galena Corporation-Olentangy district totals roughly 112.9 mills. The bulk of that 47-mill spread is school levies, with everything else in the tax bill (county, township, library, JVS) essentially identical on either side. You can verify current-year rates through the Delaware County Auditor before writing an offer, because millage changes as levies pass.
What the millage gap actually costs you
Ohio taxes property at 35% of appraised value, and reduction factors soften the effective rate below the stated millage. Even after those adjustments, the working spread between the two Galena districts sits in a range that meaningfully shifts your carrying cost. Here is how a $625,000 purchase looks under each side of the line, using effective rates that approximate what current owners are paying:
| Purchase price | District | Illustrative annual property tax | Monthly tax impact |
|---|---|---|---|
| $625,000 | Galena Corp.-Big Walnut | ~$9,400 | ~$780 |
| $625,000 | Galena Corp.-Olentangy | ~$17,000 | ~$1,415 |
| Difference | ~$7,600/year | ~$635/month |
That $635 a month is not a rounding error. Rolled into a 30-year mortgage at a rate in the mid-6s, it is the payment on roughly $100,000 of additional borrowing power. Buyers who anchor on the portal median (Homes.com reports Galena's trailing 12-month median sale price at $643,000 with a 36-day average days on market as of mid-2026) tend to underwrite one number for the whole ZIP. The county underwrites two.
This is the friction that surfaces at the closing table when the lender re-runs the escrow analysis using actual parcel data rather than the estimate on the MLS sheet. It is worth resolving during your search, not after.
What's on each side
The subdivisions in 43021 sort roughly along the boundary. Names to know:
Big Walnut side, lower total millage
- Miller Farm, the M/I Homes community off Sunbury Road with 65-plus acres of open space, is inside Big Walnut. M/I has been advertising below-market FHA financing here in 2026, most recently around 4.875% (5.436% APR) on 30-year fixed loans through M/I Financial, which changes the resale-versus-new math for this side of Galena.
- Cheshire Woods, built by Trinity Homes, is a Big Walnut community with a 3,000-square-foot clubhouse that includes a pool, fitness room, and theater. Floor plans run 1,986 to 3,812 square feet.
- Older Big Walnut inventory tends to sit along Big Walnut Road, Africa Road, and the Sunbury-adjacent sections. Big Walnut High School itself is a newer building, opened January 2022 in Sunbury, and the district's board voted in July 2024 to eliminate all student instructional and extracurricular activity fees beginning in the 2025-26 school year. That fee change is not a headline stat, but it is a real line item for families comparing districts.
Olentangy side, higher total millage
- Sherman Lakes and Estates at Sherman Lakes sit on the Olentangy side, back up to Alum Creek State Park, and include a mix of Dominion Parade of Homes-lineage builds with water views.
- Highland Lakes, The Glade at Highland Lakes, and Harbor Pointe are the lake-oriented Olentangy communities most often quoted at $600K-plus.
- Estates at Blackhawk, known for multi-level splits on wooded cul-de-sacs, is on this side.
- Trinity Homes' Hidden Creek South is the current new-build option on the Olentangy side, with floor plans from 1,778 to 3,812 square feet.
There are more subdivisions than this in 43021. Grand Oak, Mansard Estates, Meadows at Cheshire, Ravines of Alum Creek, Sage Creek, Sheffield Park, Summerwood, Walnut Grove Estates, Willow Creek, and Woods of Rome Corners are all part of the Galena inventory a buyer will see cross the MLS. Every one of them sits in a specific taxing district that a title search will confirm before closing. Do not assume.
Why the sale-versus-list spread makes sense now
Look at the Galena data from a distance and something odd shows up. In January 2026, Redfin reported a median Galena sale price of $557,000 with an average sale of $683,000, while Realtytrac and Movoto were showing median list prices between $612,500 and $675,000 in the same window. That is a wider sale-to-list gap than you would expect in a market where homes are moving in 36 to 43 days.
The gap is the two districts pulling in opposite directions inside one reported average. Big Walnut-side inventory, weighted toward newer production builds with builder rate buydowns, is transacting at more accessible prices and dragging the median down. Olentangy-side inventory, weighted toward established lake and estate communities, is anchoring the list-price average up. A single median hides the mechanism. When you underwrite Galena as one market, you overpay on one side of the line and underprice yourself out of homes on the other.
The builder-incentive wrinkle on the Big Walnut side
The M/I Homes rate offer at Miller Farm illustrates why new-construction shoppers in Galena tend to end up on the Big Walnut side even when they started their search assuming they wanted a lake community. A 4.875% FHA rate on a $500,000 new build in Miller Farm produces a lower monthly payment than a 6.5% conventional rate on a $500,000 resale in an Olentangy-side subdivision, even before the tax differential. Stack the tax spread on top and the total monthly delta between "same-price new build in Big Walnut" and "same-price resale on the Olentangy side" can approach $1,000 a month.
That does not make one side of Galena a better buy. It means the two sides answer different questions. Big Walnut-side buyers are usually optimizing for monthly cost and a shorter build timeline. Olentangy-side buyers are usually optimizing for lot type, water access through Sherman Lakes or Harbor Pointe, or a specific school assignment they already researched. Which question you are answering should drive your search radius, not the ZIP code.
What to verify before you write an offer
If a listing looks right in Galena, run the checklist before submitting:
- Pull the parcel on the Delaware County Auditor site and read the taxing district line, not just the school district field. The taxing district determines your millage.
- Ask the listing agent for the most recent full-year tax bill on the property. Estimates on the MLS often lag behind levies that have already passed.
- Confirm the school assignment with the district office directly. Boundaries have moved before, and a corner-lot address can be reassigned during a boundary adjustment.
- If it is new construction, get the builder's rate incentive in writing with the tie-in requirements, and calculate the payment both with the incentive and at a market rate. Rate promotions expire; the tax bill does not.
- On lake-adjacent lots in Sherman Lakes, Highland Lakes, or Harbor Pointe, confirm the HOA dues and any lake or dock assessments separately from the property tax figure. Those numbers are frequently omitted from portal listings.
FAQ
Does the millage difference show up in Zestimates or portal payment calculators?
Not reliably. Most portal calculators default to a statewide or county-wide effective rate. That is close enough on the Big Walnut side and materially low on the Olentangy side. Always re-run the payment with the actual parcel's tax bill before you decide what you can afford.
If I already own on one side, does a move across the boundary reset my tax base?
Yes. Ohio does not port your assessed value across a purchase. Your new bill will be calculated on the sale price on your new deed, at the new district's effective rate. Downsizing across the line can produce a smaller tax bill even at a similar price point, and upsizing across the line can produce a much larger one.
Is there a Galena address with a Sunbury mailing address, or vice versa?
Frequently. The 43021 ZIP, the "Galena" mailing city, and the school district are three different overlays that do not line up. The mailing address is the least useful of the three when you are budgeting. The parcel record is the only one that matters.
Working out which side of the Galena line fits your budget, your build timeline, and the kind of lot you actually want is exactly the kind of pre-search conversation the team at Joshua D Cooper has weekly with buyers moving into Delaware County. If you're mapping a Galena search right now and want the district overlay pulled before you tour, reach out and we'll put it in front of you. Work With Us.
