Tantallon on the Potomac by the Numbers (Part 15 of 30: The Fort Washington Files)
This is Part 15 of The Fort Washington Files from Donnell Williams Jr. and DMV Prime Properties, a thirty-part series built entirely on what 689 Fort Washington listings actually did in 2026.
This part begins the neighborhood block of the series, and it starts with the subdivision that produced more activity than any other in the zip code. Tantallon on the Potomac recorded 25 closed sales in Donnell's Bright MLS export this year, more than any other Fort Washington subdivision. It also recorded 12 listings that left the market without selling, more than any other Fort Washington subdivision.
Both of those facts are about volume. Neither is a judgment about the neighborhood or about anyone who lives in it, and this post does not make one. What follows is what the numbers say and what a buyer or a seller can actually do with them.
The row itself
Here is the full Tantallon on the Potomac line from the 2026 closed sales:
- Closed sales: 25
- Median sale price: $605,000
- Median days on market: 10
- Median above-grade square footage: 2,522
- Median annual property tax: $7,043
- Median price per square foot: $240
Every one of those figures runs in a different direction from the zip code as a whole, which is what makes the subdivision worth its own post.
Twenty-five sales in a 361-sale zip code
Tantallon on the Potomac accounted for 25 of the 361 closed Fort Washington sales this year. No other named subdivision came close. Aragona Village was next among named subdivisions at 13 closings, followed by Rose Valley Estates at 11 and Fort Washington at 10.
Twenty-one closings in the export carried no subdivision listed at all, at a median of $450,000 and 22 days on market, which is the only grouping larger than Aragona Village.
What that concentration means practically is that a Tantallon on the Potomac seller has better comparable sales available to them than almost anyone else in this zip code. Twenty-five same-year closings inside one subdivision is a real sample. A seller in a subdivision with five closings is working with thinner data and has to reach further for comparables.
Ten days
The median Tantallon on the Potomac sale closed in 10 days. The median across all 361 Fort Washington closings was 18 days.
That is fast, and it is faster in a context that makes it more notable. Homes here are larger and more expensive than the zip code norm, and this series has documented repeatedly that larger and more expensive is usually the slower end of this market. Fort Washington's 2000s-built homes, the largest group by size, carried a median of 24 days. The 115 active listings priced over $800,000 as of September 17, 2026 carried a median of 85.5 days on market.
Ten days puts Tantallon on the Potomac in the company of the fastest pockets in the zip code. Gallahan Estates closed 7 sales at a median of 1 day, Indian Queen East 5 at 6 days, Forest Knolls 6 at 7 days, and Tantallon South 7 at 8 days.
It also matters because of where 10 days sits on the days on market cliff. Across all 361 Fort Washington closings, sales that finished within 7 days sold below original list only 13.0 percent of the time, and sales finishing in 8 to 14 days did so 25.8 percent of the time. Sales that stretched past 31 days sold below original 72.5 percent of the time or worse.
$240 per square foot, against $265
The zip code median price per square foot on sale price across all 361 closings was $265. Tantallon on the Potomac came in at $240.
Put that next to the extremes in the same data and the picture gets clearer. Murray Hill posted the highest price per square foot of any Fort Washington subdivision at $355, on 5 closings at a median of $430,000 and a median 1,241 square feet above grade. Pinewood Hill posted the lowest at $190, on 7 closings at a median of $350,000 and a median 1,969 square feet.
So Tantallon on the Potomac is not the cheapest per foot in Fort Washington and it is nowhere near the most expensive. It sits below the zip code median while carrying the highest median total price among the large subdivisions at $605,000.
Part 10 of this series explained the mechanism. A house carries costs that do not scale with square footage, so bigger homes almost always show a lower number per foot. Tantallon on the Potomac's median of 2,522 square feet above grade is well above the 1,716 zip code median, and the $240 figure follows from that size more than from anything else.
The practical translation for a buyer is straightforward. Per square foot, this is one of the places in Fort Washington where a larger floor plan costs less per foot than a smaller one elsewhere in the same zip code. Part 17 of this series takes that comparison across every subdivision.
The tax line
The median annual property tax on Tantallon on the Potomac closings this year was $7,043. The median across all 361 Fort Washington closed sales was $5,485.
That gap shows up every month inside a buyer's escrow, not once a year. On a median sale price of $605,000 against a $470,000 zip code median, a higher tax line is not surprising. Tax follows assessed value, and assessed value follows price and size.
It is still a number a buyer should carry into their payment math rather than discover at the closing table. With Freddie Mac's survey putting the 30-year fixed at 6.95 percent for the week ending September 17, 2026, up from 6.76 percent the prior week and 6.26 percent a year earlier, the escrow line is doing more work in a monthly payment than it did a year ago.
Donnell is a broker rather than a tax advisor, and any buyer planning around a specific assessment should confirm it with the Maryland State Department of Assessments and Taxation rather than relying on a prior owner's bill.
The 12 that did not sell
Tantallon on the Potomac also recorded 12 failed listings this year, the highest count of any Fort Washington subdivision. Devon Hills Condo and Maplewood and Washington Overlook followed at 6 each, with Rose Valley Estates, Rosedale Estates and Fort Washington Forest at 5.
Here is how to read that honestly. The subdivision with the most closed sales also had the most listings leave without selling. That is what high activity looks like on both sides of the ledger. It is a statement about listing volume and about pricing decisions made on individual houses, not about the neighborhood and not about anyone in it.
It also fits the zip code pattern rather than contradicting it. Across Fort Washington, 144 of 505 listings that left the market this year did so without selling, a 28.5 percent failure rate. Sorted by original list price, the bands above $500,000 carried the highest failure rates in the zip code: 33.0 percent between $500,000 and $600,000, 33.3 percent between $600,000 and $800,000, and 59.4 percent above $800,000, where 19 failed against 13 closed.
A subdivision with a $605,000 median sale price is listing a lot of homes into those upper bands. The zip-code-wide failure rate in those bands is roughly a third. Twelve failures against 25 closings is consistent with that, and it is consistent with the finding that drives this entire series.
What the failed listings across Fort Washington had in common
The failed group across all 144 Fort Washington listings carried a median original list price of $534,748 against $479,900 for the closed group, and a median of 50 days on market against 18. Half of them cut their price, with a median cut of $25,000, and still did not sell. Only 29 percent of closed listings ever cut at all.
The measure that matters most is this one. Failed listings were priced at $267 per square foot on original list. Closed listings were priced at $273. Failed listings were also bigger, a median 1,952 square feet above grade against 1,716 for the closed group.
They were not overpriced per square foot. They were priced at an absolute number the local buyer pool could not reach. That is the finding, and it applies in Tantallon on the Potomac exactly as it applies everywhere else in the zip code.
One new construction closing
Only 9 of the 361 closed Fort Washington sales this year were new construction, at a median of $835,235, a median of 7 days on market, and a range from $710,000 to $1,500,000.
Of those 9, seven were in Gallahan Estates, one was in Spring Ridge, and one was in Tantallon on the Potomac. Gallahan Estates on its own closed 7 at a median of $835,235 and a median of 1 day on market.
That single Tantallon on the Potomac new construction closing is worth noting precisely because it is a single closing. Fort Washington is overwhelmingly a resale market, with a median year built of 1976 across all 361 sales. A buyer looking here should plan on buying an existing home.
What to take from the whole row
For a seller in Tantallon on the Potomac, the encouraging numbers are 25 closings and 10 days. Deep comparable data and a fast median are advantages most Fort Washington sellers do not have. The number that requires care is $605,000, because it puts most listings here into the price bands where roughly a third of Fort Washington listings failed this year.
For a buyer, the row describes a larger home on a higher tax line at a below-median price per square foot, moving quickly enough that a slow decision is a real risk.
Get the subdivision-level numbers for your house
A zip code median is a starting point. A subdivision median is closer. What a specific house on a specific street should be listed at, or offered on, takes the actual comparable sales and the actual standing inventory. Donnell Williams Jr. is the broker-owner of DMV Prime Properties at 12815 Old Fort Road in Fort Washington, and he keeps this data current at the subdivision level because it is his home market. He will pull the 25 Tantallon on the Potomac closings, show what sold and what did not, and tell a buyer or a seller where their house actually sits. Call 301.818.0313 or email donnell@dmvprimerealty.com.
Part 16 of The Fort Washington Files splits the four Tantallons apart and shows why they are four different markets.
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