Mandeville's Two ZIP Codes Reached the Same Supply Number From Opposite Directions

"Percent changes are calculated using rounded figures and can sometimes look extreme due to small sample size." That line is printed at the bottom of every Local Market Update from the New Orleans Metropolitan Association of Realtors, and in Mandeville it carries a lot of weight.

Each of Mandeville's two ZIP codes closes roughly 25 to 35 homes a month. A sample that small swings hard. One month's median can jump or drop by a third because of which houses happened to close. The year-to-date figures through September 2026 move much less, and they show the two ZIP codes heading different ways. In 70448, homes are selling faster and more of them are closing. In 70471, fewer owners are listing, and the homes that do list are taking longer to sell. In September both ZIP codes ended up at 3.4 months of supply, but they got there for different reasons.

Where the Two ZIP Codes Sit

The ZIP code on a listing tells you which set of comps you are reading, so the geography matters first. Old Mandeville is in 70448. That includes the Mandeville Trailhead at 675 Lafitte Street, the St. Tammany Parish Library's Mandeville Branch at 844 Girod St., City Hall at 3101 East Causeway Approach, and Fontainebleau State Park at 62883 Hwy. 1089.

The 70471 addresses include Beau Chêne Country Club at 602 North Beau Chêne Drive, the library's Causeway Branch at 3457 Hwy. 190, Bub's Mandeville at 3847 LA-22, and the Visit The Northshore Visitor Center at 68099 Highway 59, just north of I-12. Both ZIP codes use a Mandeville mailing address, but each has its own sales report.

Three Months of Medians, Side by Side

Here are the monthly median sale prices from NOMAR's July, August and September 2026 reports, each compared with the same month of 2025.

From August's report alone, a reader would think 70471 had a price crash of one-third. The drop came from the comparison month. In August 2025, the 27 homes that closed in 70471 produced a $625,000 median. The 26 that closed in August 2026 produced $415,000. One month later the same ZIP code showed an 18% gain. That came from 32 September closings measured against only 15 the September before, when the median was $322,000.

In September 2026 the two medians were $379,000 and $380,000, which makes the ZIP codes look interchangeable. Over the full year they are not.

What Nine Months of Closings Say Instead

Year-to-date figures pool roughly 240 to 290 sales per ZIP code. That is large enough for a few unusual closings to stop driving the result. Here is the picture through September 2026 compared with the same nine months of 2025.

In 70448, sellers listed at about the same pace as in 2025, and buyers closed on more homes in less time. In 70471, about 41 fewer homes came to market through September than a year earlier. Closings barely moved, and the typical home took nine more days to sell than in 2025. The median gap of nearly $50,000 between the two ZIP codes held all year, even though September's medians matched.

Same Supply Figure, Different Causes

In September 2026, NOMAR put both ZIP codes at 3.4 months of supply. In 70448 that figure was down from 4.1 a year earlier, and in 70471 it was down from 3.8. Months of supply is inventory divided by the recent pace of sales, so it shrinks if sales speed up or if fewer homes come on the market. Mandeville's two ZIP codes show each case.

In 70448, inventory fell from 118 to 107 homes as closings rose, so faster sales drove the drop.

In 70471, inventory fell further, from 99 homes to 85. Over the same period new listings dropped by a third in September alone, from 33 to 22, and pending sales fell from 25 to 18. The year-to-date drop in new listings has stayed steady: down 10.2% through July, 8.6% through August and 10.8% through September. Meanwhile, year-to-date days on market rose from 49 to 52 to 54 over those same three reports.

Tight supply usually comes with faster sales. In 70471, supply got tighter while homes took longer to sell. That pattern suggests a market where fewer owners are choosing to list, more than one where buyers are competing for scarce homes.

For a buyer, that changes the plan. In 70471, the house you want may simply not be listed this season, but the listings that are available have tended to stay on the market long enough for a careful look. In 70448, the pace is quicker, so the decision window is shorter.

Where 70448 Buyers Found Room on Price

The quick pace in 70448 has not meant sellers there always get their number. In July 2026, 70448 sellers received 98.7% of list price. In August that fell to 95.8%, and in September to 95.5%, compared with 97.6% in September 2025. Days on market in those same two months stayed in the 40s, at 44 in August and 47 in September.

Homes in 70448 kept selling quickly in late summer, but buyers paid a smaller share of the asking price. That points to asking prices that ran ahead of what buyers would pay, rather than a shortage of buyers. In 70471, the percentage held between 96.7% and 97.0% in August and September. NOMAR notes that these price figures do not account for seller concessions, so the real negotiated discount on some sales may be larger than the percentage shows.

The Parish Numbers Have the Same Mix Problem

At the parish level, the mix effect is visible even with ten times as many sales. NOMAR's St. Tammany Parish report for September 2026 shows a median sale price of $309,950, up 6.7%, while the average fell 1.9% to $366,269 on 318 closings. When the median rises and the average falls, the typical home sold for more while fewer high-end homes closed. Neither number on its own describes the parish's price direction.

The parish report shows the 70471 pattern at a larger scale. Homes for sale fell 10.4% to 1,402, and new listings fell 10.7% to 417. At the same time, days on market until sale rose 25% to 70. Price cuts are also common. FRED's St. Tammany series, built on Realtor.com data, counted 472 listings with a price reduction in September 2026 out of 1,383 active listings. By our calculation, that is roughly one listing in three. FRED's year-over-year series show the number of price-reduced listings up 5.36% from September 2025 even as active listings fell 5.79%.

Reading a Mandeville Comp Sheet This Fall

The data points to a few specific habits for anyone comparing homes across the two ZIP codes:

1. Use the year-to-date median as the baseline. Through September 2026 it was $385,000 in 70448 and $433,000 in 70471. Any single month can be off by tens of thousands of dollars from that baseline.
2. Check whether a monthly change compares like with like. If the same month last year had half as many closings, as 70471's September did, the percentage change mostly reflects that thin comparison month.
3. Watch new listings in 70471. That number has driven tighter supply there all year. A rise would change the picture faster than any price figure.
4. In 70448, check sale price against list price, not just days on market. Homes have moved quickly, but August and September sales closed further below asking than a year earlier.
5. Compare a home only with sales from its own ZIP code. A 70448 cottage near the Trailhead and a 70471 home near Beau Chêne can post the same September median and still sit in different markets.

A Short FAQ

Which ZIP code is "more expensive"? Over the first nine months of 2026, 70471 had the higher median, at $433,000 against $385,000, and the higher average, at $509,956 against $422,173. September's nearly identical medians came from that month's mix of sales, and the gap held across the full year.

Did 70471 prices fall by a third in August? The August 2026 median was 33.6% below August 2025. In the same report, the year-to-date median was up 1.9%. The decline reflects an unusually high comparison month in 2025, not a broad price drop.

Does 3.4 months of supply mean both ZIP codes favor sellers equally? The figure is the same, but the causes differ. In 70448, faster sales shrank supply. In 70471, fewer homes came to market, and the homes that did list took longer to sell.

If you're weighing a home in 70448 against one in 70471, or trying to price a sale against a monthly figure that keeps moving, Felicity Kahn & Associates can pull the year-to-date comps for your ZIP code and the homes that actually compete with yours. Get your free home valuation, and we'll show you which Mandeville numbers apply to your address.