Two colonials go on the market in Ardsley the same week. Same school district, same commute to Grand Central, same walk to the Saw Mill River trail. One lists at $999,000. The other lists at $1,050,000. A buyer touring both assumes the second one simply has a nicer kitchen or a bigger lot. Sometimes that is true. But in Ardsley this year, the gap between those two numbers is just as often about a single line in the New York State tax code that has nothing to do with square footage.
That line is the state's so called mansion tax, a flat 1 percent charge on residential purchases of $1 million or more anywhere outside New York City. It was written into law in 1989 and the threshold has never moved. In most of the country, and even in most of Westchester, that number sits comfortably above what a typical buyer is shopping for, so it barely enters the conversation. Ardsley is one of the few places in the county where it does not sit comfortably anywhere. It sits right in the middle of the market.
The Threshold Is Sitting Inside Ardsley's Price Range, Not Above It
Look at where Ardsley's numbers actually land as of this year. Redfin's June 2026 data put the town's median sale price at $1,061,922, down 12.6 percent from the year before but still above the taxable line. Homes.com's trailing 12 month figure came in at $1,130,000, up 29 percent from the prior year, with a median list price of $1,050,000. Zillow's broader measure, which folds in condos across every Ardsley zip code, showed a typical home value of $846,883, down slightly over the past year.
Put those three numbers side by side and they look contradictory. They are not. They are measuring different slices of the same town. Ardsley's housing stock runs from roughly $400,000 condominiums up to $2 million estate properties, and the single family homes that dominate local Realtor conversations cluster right around, and often just above, the $1 million mark. The Zillow figure looks lower because it averages in the condo stock sitting well under the threshold. The Redfin and Homes.com figures track closer to what a single family buyer will actually encounter, and both sit above the line.
This is the detail a headline median price will never tell you. If you are comparing Ardsley to another Westchester village using a single averaged number, you may be comparing a town where the tax is a given against one where it is a coin flip, without realizing it.
Westchester's Countywide Number Tells the Same Story
Ardsley is not an outlier by accident. It reflects something happening across the county. OneKey MLS data reported for February 2026 put Westchester County's overall median single family sales price at $999,000, one dollar under the mansion tax line. That is not a coincidence in the way a buyer might assume. When a huge share of a market's inventory sits within a few thousand dollars of a hard tax cliff, pricing behavior on both sides of the table starts to bend around that number.
Here is how that compares to a town where the threshold barely registers. Rye's median list price ran $3.5 million in February 2026 and its median sale price was $2.2 million in March 2026. A Rye buyer pays the 1 percent tax on every realistic purchase in that market. There is no pricing strategy that gets them under it, so the tax becomes a fixed line item, not a variable one.
| Market | Typical price point | Mansion tax status | What it means for a buyer |
|---|---|---|---|
| Ardsley | $1.05M to $1.13M for single family, 2026 | On the line | Whether you owe it can depend on the specific home and the specific offer |
| Westchester County overall | $999,000 median, Feb 2026 | Just under the line | Countywide pricing already clusters at the threshold |
| Rye | $2.2M to $3.5M | Always above | The tax is a fixed cost with no negotiating angle |
An Ardsley buyer is shopping in the one part of the county where the tax is genuinely in play rather than automatic or absent.
The Tax Itself Behaves Like a Cliff, Not a Ramp
The mechanics matter here because they are counterintuitive. The 1 percent rate outside New York City applies to the entire purchase price once you cross $1 million, not just to the amount above it. A home that sells for $999,999 owes nothing. The same home at $1,000,000 owes $10,000. There is no phase in. The buyer pays it at closing, and most lenders will not roll it into the mortgage, so it has to show up as cash at the table alongside the down payment and other closing costs.
That cliff is why price negotiations near $1 million in Ardsley can look unusual to someone used to shopping in a market where round numbers do not carry tax consequences. A few tactics show up repeatedly in how buyers and sellers handle it locally:
- Negotiating the contract price down to $999,000 or similar instead of settling at $1,005,000 or $1,010,000, since crossing the line costs far more than the price difference itself
- Documenting genuine personal property, such as furniture or appliances, under a separate bill of sale so only the real estate itself is priced against the threshold, which requires a properly structured contract and should go through an attorney rather than being estimated informally
- Asking for a seller credit that offsets the tax without changing who technically owes it, which shifts the practical cost even though the legal obligation still falls on the buyer
None of these are do it yourself moves. They belong in the hands of a real estate attorney who can document the numbers in a way that holds up if it is ever questioned, but knowing they exist changes how a buyer reads a listing priced at $998,000 in a neighborhood where $1.1 million homes are common.
This Year's Albany Fight Ended Without Touching Westchester
Buyers researching this topic in early 2026 ran into a real complication. The State Senate and Assembly both proposed sweeping increases to the mansion tax as part of their one house budget proposals, with an effective date floated for June 1, 2026. That created a genuine window of uncertainty for anyone closing in the spring.
The final 2026-2027 state budget, enacted May 26, 2026, resolved it. The broad rate hikes that had been on the table were dropped. What did pass was a new pied-à-terre tax, a recurring annual surcharge on non-primary residences in New York City valued at $5 million or more, confirmed in Holland and Knight's legal analysis of the enacted legislation. That surcharge is defined strictly around the five boroughs. It does not extend to Westchester, and it does not change the flat 1 percent rate that applies to an Ardsley purchase. A buyer budgeting for a home near $1 million today is working against a rule that just survived its most serious legislative challenge in years, which is about as much stability as tax policy offers.
What This Means If You Are Comparing Ardsley to Somewhere Else
If you are weighing Ardsley against another Westchester village, the mansion tax is not a footnote. It is one of the few costs that changes based on exactly which listing you choose rather than which town you choose. In a market like Rye, the tax is baked into every conversation from the first showing. In Ardsley, it is genuinely negotiable in a way that rewards a buyer who understands the mechanics before they write an offer, not after.
Does the mansion tax apply the same way to condos as it does to single family homes in Ardsley?
Yes. Outside New York City, the 1 percent rate and the $1 million threshold apply the same way regardless of property type. A condo priced at $1,050,000 triggers the same tax as a single family home at the same price.
Who actually pays the mansion tax, the buyer or the seller?
The buyer pays it, and it is due at closing. Some buyers negotiate a seller credit to offset the cost, but the legal obligation to pay stays with the buyer.
Can the mansion tax be included in the mortgage?
Generally no. Most lenders treat it as a cash requirement separate from the loan amount, so it needs to be part of your cash to close budget alongside the down payment and other closing costs.
If you are trying to figure out what a specific Ardsley listing actually costs once every closing line item is accounted for, that is exactly the kind of detail worth walking through before you write an offer, not after. The Cindy Kief Team works Westchester's river towns closely enough to know where a market's headline price and its real cost diverge, and we would be glad to look at your specific situation together. Schedule a consultation whenever you are ready to talk through the numbers.