Published October 18, 2026 in Market Update

One part of Centreville moved fast. Another slowed down

Centreville is not one market. It is two. The Real Estate Data Aggregator counted 214 homes sold across both ZIP codes in the three months ending August 31, 2026. But 20120 and 20121 behaved nothing alike. If you price or offer based on the town average, you are using the wrong number.

The gap between the two ZIP codes

ZIP 20120: still competitive, but prices dipped

The Real Estate Data Aggregator put the median sold price in 20120 at $665,000. That is down 2.2% from the same three months in 2025. Prices slipped a little. But demand did not. Sales volume rose 22.9% year over year. Nearly 3 in 5 homes went under contract within two weeks of listing. The sale to list ratio came in at 101%, up 0.8 points from a year ago. Sellers who priced correctly got paid above ask.

ZIP 20121: more inventory, more days, more room to negotiate

The Real Estate Data Aggregator counted 69 homes sold in 20121 in the same period. That is down 18.8% from a year before. The median sold price was $516,000, down 9.5% year over year. Homes sat for a median of 42 days, which is 10 days longer than the same period in 2025. Inventory jumped 71.4% year over year. More supply and fewer buyers means buyers in 20121 have more room to negotiate. Sellers need to know that going in.

How this fits the wider Northern Virginia picture

The Northern Virginia Association of REALTORs reported a $744,950 median sold price across Northern Virginia in September 2026. Both Centreville ZIP codes sit well below that figure. Northern Virginia active listings rose 30.7% year over year in September 2026, according to the same report. The inventory growth in 20121, up 71.4%, outpaced even that regional rise. That is a local signal, not a regional one. Buyers and sellers in 20121 are operating in a softer pocket inside an otherwise firm region.

Nationally, Realtor.com reported that mortgage rates climbed above 7% for the first time since January 2025. Fannie Mae, as reported by CNBC, forecast an average 30-year fixed rate of 7.4% for the fourth quarter of 2026. Rates at that level affect how much a buyer can offer. In a softer ZIP like 20121, that pressure shows up in price cuts and longer days on market. In a tighter ZIP like 20120, well-priced homes still drew offers above list.

What this means if you are selling

In 20120, the Real Estate Data Aggregator shows 46.2% of homes sold above list price. That is up 8.9 points from a year ago. If you price to the right comps, you can still draw competing offers. In 20121, only 39.1% sold above list. Supply is up 71.4% and pending sales are down 24.1%. Price it wrong and you will sit. The comp set you use must match your ZIP, not the town as a whole.

What this means if you are buying

In 20120, nearly 3 in 5 homes went under contract within two weeks. Coming in low is a risk. In 20121, only 48.5% of homes went under contract that fast, and that share dropped 12.4 points from a year ago. Buyers in 20121 have more time and more leverage. Know which ZIP you are in before you write your offer.

One more thing. The Real Estate Data Aggregator tracks ZIP codes. Your street may read differently from the ZIP average. A block closer to a school zone line or a commute route can shift the numbers. I look at the street level, not just the ZIP.