Two people came to the same number this spring from opposite directions. One had just sold a two-flat in Chicago and wanted a yard in Naperville. The other lived in Naperville, had launched two kids into college, and wanted to trade the mower for a doorman. Both landed on roughly $650,000 as their working budget. Both assumed the other market was the expensive one.
Neither was wrong exactly. They were just comparing the wrong number. The sale price tells you what something cost someone else. It does not tell you what you are actually buying, or what it will cost you to keep buying it every year after closing.
The Number That Flips the Story
Compare price per square foot instead of median sale price, and the tidy "suburbs are cheaper, city is pricier" story stops holding up once you get specific about location.
| Market | Time window | Median sale price | Price per square foot |
|---|---|---|---|
| Naperville, citywide | 3 months ending May 2026 | $595,000 | $273 |
| Downtown Naperville | 3 months ending May 2026 | $960,000 | $508 |
| Chicago, citywide | 3 months ending May 2026 | $420,000 | $318 |
| Downtown Chicago condo core (the Loop) | April 2026 | roughly $420,000–$472,500 | $442 |
Look at the last two rows against the second row. Downtown Naperville's walkable core, the blocks around the Metra station and Main Street, priced at $508 per square foot over the three months ending May 2026. The Loop, the densest and most expensive condo core in the city, priced at $442 per square foot in the same general window. The suburb's downtown outpriced the city's downtown, per square foot.
That is not what most buyers expect walking into this comparison, and it is the reason the median sale price is a misleading shortcut. A $650,000 budget in downtown Naperville buys roughly 1,280 square feet at that neighborhood's pricing. The same $650,000 in the Loop buys closer to 1,470 square feet at $442 per foot. The city, in this specific pocket, is currently the better square-footage deal, not the worse one.
Widen the lens back out to citywide averages and the picture tilts the other way: Naperville overall runs $273 per square foot against Chicago's $318, a gap Redfin's tracking puts at roughly 16 percent in Chicago's favor for cost per foot, even as Chicago's citywide median sale price of $420,000 sits well below Naperville's $595,000. Two true numbers, two different conclusions, depending on which one you anchor on.
The Naperville Number Is Actually Two Markets
Part of why the citywide comparison is so slippery is that "Naperville" is not one housing product. The local MLS's trailing 12-month data through March 2026 shows detached single-family homes carrying a median sale price of $699,000, while attached homes, the townhomes and condos, carry a median of $333,250. Those two figures average out to something in between when a national data source reports "the Naperville median," but nobody actually buys the average. They buy one or the other.
That split matters for this comparison specifically. If the Chicago-side buyer is shopping condos, the honest Naperville comparison is not the $699,000 detached figure. It is the $333,250 attached figure, plus whatever premium a specific subdivision or the downtown corridor commands. Get the product type wrong on either side of the comparison and the whole exercise produces a number that describes nothing real.
Same Calendar, Different Shape: How the Tax Bill Actually Moves
Square footage is the half of this comparison most people already think to check. The half that catches buyers off guard later is how the property tax bill behaves over time, because DuPage County and Cook County do not just charge different rates. They move on different schedules, and the shapes of those schedules are not the same.
DuPage County's effective property tax rate runs in the neighborhood of 2.0 to 2.2 percent of market value, a figure that holds fairly steady year to year and comes due on a predictable two-installment calendar, with 2026 due dates falling on June 1 and September 1. A $650,000 Naperville home taxed at the midpoint of that range works out to roughly $13,650 a year. The bill still moves with reassessed value and local levies, but it moves in small, expected steps, and every township in DuPage sits on the same three-year assessment cycle, publicly posted through the county clerk's property tax reports.
Cook County works differently, and the mechanism is worth understanding before you commit to a downtown unit. Cook County reassesses one-third of the county every year on a rotating basis. The City of Chicago's most recent citywide cycle ran 2024 through 2026, which means the city will not face a full reassessment again until 2027, per the Cook County Assessor's own assessment calendar. The south and west suburbs are in their reassessment window in 2026 instead. Naperville sits entirely in DuPage and Will counties, so none of this Cook County cycle touches it directly. But it matters a great deal to anyone buying in Chicago, because reassessment years are when tax bills move in one lump rather than in small annual steps.
The lump can be larger than the underlying market justifies. Cook County Assessor Fritz Kaegi's office reported that when the Board of Review cut commercial property assessments by close to 20 percent during the last cycle while cutting residential assessments by only about 1 percent, the shifted burden added roughly $700 to the tax bill of every home in Chicago, a redistribution his office called out directly in reporting from WTTW. Kaegi put it plainly: "these increases for residents are outrageous, especially as commercial properties are seeing their taxes go down."
None of that is a reason to avoid Chicago. It is a reason to ask, before you buy, which reassessment year you are walking into, and to budget for a tax bill that can jump in a single cycle rather than climb gradually the way a DuPage bill does.
The Line Naperville Buyers Never Have to Budget For
The other carrying cost that separates these two purchases is one that does not exist at all for most Naperville detached buyers: the HOA line, and its less predictable cousin, the special assessment.
Condo dues in Chicago average around $425 a month as of 2026, and that number does not sit still. HOA fees in Chicago buildings have historically climbed close to 6 percent annually, a pace that would carry today's $425 monthly fee past $761 within a decade, according to carrying-cost data compiled by The Condo Trap. Add in insurance, and average special assessments across Chicago buildings running near $14,000, and the true monthly cost of owning a mortgage-free condo in the city can exceed $821 a month once everything is counted, separate from the mortgage entirely.
A detached home in Naperville does not carry an equivalent mandatory line item in most cases. It carries its own maintenance costs, a roof, a furnace, a driveway, but those arrive on the owner's schedule, not a board's. The condo buyer is trading that flexibility for a building that handles the roof and the furnace collectively, and paying a rising monthly fee plus occasional lump-sum assessments for the trade.
What This Means for a $650,000 Decision
Put the pieces together and the comparison stops being about which market is cheaper and starts being about which cost structure fits the buyer. The Naperville side of this trade offers a flatter path: a tax bill that moves in small increments on a known calendar, no mandatory monthly association fee on most detached product, and a downtown corridor that is not, contrary to assumption, the bargain option per square foot. The Chicago side offers more square footage per dollar in the specific pocket where that holds true, a tax bill currently past its most recent reassessment shock but due for another cycle in 2027, and a monthly HOA line that compounds in a way a Naperville mortgage payment does not.
Neither shape is wrong. They just fit different timelines. A buyer planning to hold for three years cares more about today's price per square foot. A buyer planning to hold for fifteen cares more about how the tax bill and the HOA line behave in year eight.
A Few Questions This Comparison Raises
Does Naperville ever see tax surprises the way Chicago does?
DuPage County reassesses on its own three-year cycle, separate from Cook County's, and the effective rate has stayed in a fairly narrow band. Naperville buyers still see rate variation by ZIP code and by school district, so the address matters, but the county-wide swings tied to Chicago's Board of Review commercial-to-residential shifts do not apply here.
Is every Chicago condo building's HOA growing at the same pace?
No. The 6 percent average pace and the $14,000 average special assessment are portfolio-wide figures, not a promise for any specific building. A building with a recently funded reserve study and a completed capital plan can look very different from one that has deferred major work. That is a document worth reading in full before writing an offer, not skimming after.
If price per square foot flips the story, is it the only number that matters?
It is the number most buyers skip, which is why it matters here. It is not the only one. Lot size, parking, storage, and what the HOA dues actually cover all change what a given square foot is worth to a specific household.
If you are trying to figure out what your own $650,000, or any other number, actually buys once you account for the tax calendar and the carrying costs on both sides of the city line, that is exactly the kind of math Nina Trivedi walks through with clients before they write an offer, not after. Start the Conversation.
