Price from closed sales, not from an online estimate. A Cornerstone comparative market analysis uses 3 to 6 strong sold comparables, recent enough to reflect current financing conditions, adjusted for condition, lot, and exact neighborhood, then checks the range against pending sales and the active competition a buyer will see the same weekend. In Fairfax, our published guidance is to price within 2 to 3% of the last 90 days of comparable sales and just under the search bands buyers filter by (Fairfax pricing guide, October 2026). Price to the data and let competition negotiate; pricing above the valuation to leave room is the most expensive mistake a seller can make.
Key Takeaways
- A professional valuation is a supported range built from recent closed sales, not a single automated number.
- A Cornerstone CMA uses 3 to 6 strong sold comparables, adjusted for condition, lot, size, and exact neighborhood.
- In Fairfax, price within 2 to 3% of the last 90 days of comparable sales, and just under the search bands buyers filter by.
- September 2026 NVAR medians: Fairfax County $749,750, Arlington $655,000, Alexandria $660,000. County medians are context; your price still comes from subdivision comparables.
- Pricing above the valuation to leave negotiation room reduces showings, and fewer showings mean fewer offers.
What does a valuation actually measure?
A valuation is not a guess and not a single number pulled from a database. It is a comparison. Your agent looks at homes like yours that sold recently nearby, then adjusts for the differences: a renovated kitchen, an extra bedroom, a busier street, a larger lot. The result is a supported range, not a wish.
Online estimates use the same public records but miss what matters most. They cannot see your new roof, your dated bathrooms, or the power lines behind the backyard. In Fairfax, Arlington, and Alexandria, where two streets over can mean a different school pyramid or a different commute story, those details move the number. That is why an in-person valuation almost always beats an algorithm.
We compared the major online estimates against actual Northern Virginia sales in our guide to when a Zestimate is off. The pattern is consistent: the model is a starting point, never the pricing decision.
How does a Cornerstone CMA choose its comparables?
These are the selection rules behind every Cornerstone pricing analysis, promoted from the questions sellers ask us most. They match the method in our guide to comparative market analysis and hands-on pre-sale preparation, so you can check any agent's work against them:
| Rule | How we apply it |
| Sale status | Closed sales carry the most weight; pending sales show direction; active listings show your competition |
| Number of comparables | 3 to 6 strong sold comparables; one perfect comp beats five weak ones |
| Recency | Recent enough to reflect current financing conditions; in Fairfax, the last 90 days of comparable sales anchor the range |
| Proximity | Same neighborhood first; the exact street and school pyramid matter more than the ZIP code |
| Similarity | Similar size, condition, updates, and lot; closer matches carry more weight |
| Adjustments | Every difference is adjusted and shown: condition, lot, square footage, bedrooms, updates, and location within the neighborhood |
| Cross-check | The supported range is checked against pending sales and the active competition a buyer will see the same weekend |
What does a worked CMA look like?
Here is a real one, anonymized. This example is from a Cornerstone comparative market analysis prepared on October 26, 2026, from Bright MLS records, for a detached split foyer home in the Kings Park subdivision of Springfield, in Fairfax County: 4 bedrooms, 3 full baths, 1,200 above grade finished square feet, built in 1962, listed at $749,900. The three closed comparables are all in the same subdivision, all detached, all 4 bedrooms, and all 1,200 above grade finished square feet, which is why this set carries weight. Street addresses and MLS numbers are withheld.
| Home | Closed date | List price | Closed price | Seller concession | Net price after concession | Price per above grade sq ft |
| Subject home | Listed, not sold (44 days on market at analysis) | $749,900 | Not yet closed | Not applicable | Not applicable | $624.92 at list price |
| Comparable 1 | Sep 10, 2026 | $775,000 | $790,000 | $6,500 | $783,500 | $658.33 |
| Comparable 2 | Jul 1, 2026 | $699,000 | $699,000 | $3,000 | $696,000 | $582.50 |
| Comparable 3 | May 11, 2026 | $825,000 | $797,000 | $0 | $797,000 | $664.17 |
| Average of the 3 closed sales | May to Sep 2026 | $766,333 | $762,000 | $3,167 | $758,833 | $635.00 |
Read the table the way a pricing conversation should. The closed range is $699,000 to $797,000. The average closed price is $762,000, and the average net price after seller concessions is $758,833. The subject home was listed at $749,900, inside the closed range and below the average closed price, at $624.92 per above grade square foot against a comparable average of $635.00. That position is deliberate: priced from the closed sales, not above them.
Why are there no dollar adjustments in this example? Because the comparables match the subject on the items that usually drive the biggest adjustments: property type, bedrooms, and above grade finished square feet, in the same subdivision. The differences that remain, bath configuration, condition and updates, lot, and sale dates between May and September 2026, are handled by weighting: the most similar and most recent sales carry the most weight, seller concessions are netted out before prices are compared, and days on market for the closed sales (10, 24, and 5 days, in the order shown) confirm the range reflects current demand. When a comparable differs on size or condition, the adjustment is made in dollars and shown in the grid, as the FAQ below explains.
Why do these three markets price differently?
These three markets price differently for structural reasons. Fairfax is a large county with wide variation between corridors. Arlington is compact, dense, and transit-oriented, so small location differences carry weight. Alexandria is an independent city with its own assessment office and a mix of historic and newer stock. A valuation has to respect those differences instead of treating Northern Virginia as one market.
What are the latest county benchmarks?
County medians are context, not a price for your home, but they tell you which direction each market is moving. These are the September 2026 figures from the Northern Virginia Association of Realtors (NVAR), derived from Bright MLS as of October 12, 2026, and published on October 16, 2026. The sample in each row is that jurisdiction's closed sales for September 2026.
| Jurisdiction | Median sold price, Sep 2026 | Change vs Sep 2025 | Average sold price | Closed sales (sample) |
| Fairfax County | $749,750 | +5.6% | $903,940 | 897 |
| Arlington County | $655,000 | -4.6% | $883,455 | 175 |
| City of Alexandria | $660,000 | -11.4% | $750,137 | 143 |
| Loudoun County | $758,500 | +0.8% | $843,880 | 338 |
| NVAR region overall | $744,950 | +4.2% | $881,456 | 1,250 |
Two cautions before you use these numbers. First, a median is the middle closing price for that month, not the value of any one home; it moves when the mix of homes that sold changes, which is one reason a county median can fall in a month when individual well priced homes still sell strongly. Second, pace differs by market: the NVAR region averaged 28 days on market in September 2026 with 2.5 months of supply, while Loudoun County averaged 31 days on market with 2.41 months of supply (NVAR, September 2026). Your price still comes from your subdivision comparables, as the worked example above shows; the county table only tells you how much room the market around you is giving.
How does a valuation become a pricing strategy?
The pricing strategy is the step most sellers skip. A valuation tells you what the home is worth. A strategy decides the asking price: the number that gets the right buyers through the door in the first two weeks, when interest is highest. Sometimes that number matches the valuation. Sometimes it sits slightly below to invite competition. It should never be set above the valuation just to test the market, because testing the market is how listings go stale.
Which pricing mistakes cost sellers the most?
Three pricing mistakes show up again and again. First, adding negotiation room on top of the valuation, which just makes the home look overpriced next to fairly priced competition. Second, anchoring to the highest comp in the neighborhood instead of the most similar one. Third, pricing the home for what the owner spent on it rather than what buyers will pay for it. Every one of these is avoidable with a data-first conversation.
What should a good pricing conversation include?
A good pricing conversation with your agent should include the comparable sales they used and why, the adjustments they made, what is currently competing against your home, and what happens if the first two weeks bring no offers. If an agent gives you a number without showing that work, get a second opinion before you sign anything.
Thinking about selling in Fairfax, Arlington, or Alexandria? Start with a real valuation, not a guess. Text Cornerstone Realty Group at (571) 441-1031 for a 5-minute pricing conversation, or request a free home valuation and we will walk the comps with you before you make any decisions. You can also start with a free home valuation, read how a listing agent should be hired in our listing agent answer, and see what happens when an appraisal comes in low in our guide to appraisers' secrets in Fairfax County.
Sources: Fairfax County Department of Tax Administration, Arlington County Real Estate Assessments, and the City of Alexandria Finance Department publish the assessment and sales data used in every local valuation; comparable sale records come from Bright MLS. The Fairfax guidance to price within 2 to 3% of the last 90 days of comparable sales is from our Fairfax pricing guide, published October 2026. Assessments reflect tax value, not market value. Verify current figures with the relevant office before relying on them. County benchmarks: Northern Virginia Association of Realtors (NVAR) September 2026 market statistics, derived from Bright MLS as of October 12, 2026, and published October 16, 2026; geography is each jurisdiction named in the table and the NVAR region (Fairfax and Arlington counties, the cities of Alexandria, Fairfax, and Falls Church, and the towns of Vienna, Herndon, and Clifton); the sample is September 2026 closed sales (897 in Fairfax County, 175 in Arlington County, 143 in the City of Alexandria, 338 in Loudoun County, 1,250 in the region), and each median is the middle closed price for that month. Worked CMA example: anonymized from a Cornerstone comparative market analysis prepared October 26, 2026, from Bright MLS records; the subject and comparables are detached homes in the Kings Park subdivision of Springfield, Fairfax County, matched on property type, bedrooms, and above grade finished square feet; 3 closed comparables from May to September 2026; net price means the closed price minus the seller concession recorded in that analysis.
FAQ
How is a professional valuation different from an online estimate?
An online estimate is an automated model working from public records. A professional valuation adds what the model cannot see: your home's actual condition, recent updates, lot characteristics, and micro-location factors. In markets like Arlington and Alexandria where block-level differences matter, that human layer is where accuracy comes from.
How far back should comparable sales go?
Recent is relative to the market. In active corridors, the most useful comps sold within the last few months. Older sales can support the analysis but should carry less weight, because financing conditions and buyer demand shift. Your agent should explain why each comp was chosen, not just list addresses.
Should I price above the valuation to leave room for negotiation?
This is the most expensive myth in selling. Buyers compare your asking price to other listings, not to your valuation. An inflated price does not create negotiation room. It reduces showings, and fewer showings mean fewer offers. Price to the data and let competition do the negotiating for you.
Do county tax assessments matter when pricing my home?
Assessments determine your tax bill, not your market value. They are set on a mass-appraisal cycle and lag the market by design. Buyers and appraisers price from comparable sales. An assessment can be a useful sanity check, but it should never set your asking price.
How do I know if my home is overpriced after the first two weeks?
Watch showings and feedback, not just days on market. Strong marketing with very few showings usually points to price. Plenty of showings with no offers usually points to condition or presentation. Either way, the first two weeks are diagnostic. A good agent reads the signals with you and adjusts once, decisively, instead of chasing the market down in small cuts.
How recent should comparable sales be?
Recent enough to reflect current financing conditions. In Fairfax, our published guidance anchors on the last 90 days of comparable sales. Older sales can support the analysis, especially in neighborhoods that trade rarely, but they carry less weight, and your agent should explain why each comp was chosen, not just list addresses.
What is the difference between a CMA, an appraisal, and a Zestimate?
A CMA is your agent's pricing analysis, built from recent comparable sales to set your asking price. An appraisal is a licensed appraiser's opinion of value, usually ordered by the buyer's lender after you are under contract. A Zestimate is an automated estimate from public records that cannot see your home's condition or updates. Price from the CMA, prepare for the appraisal, and treat the automated estimate as a rough starting point. Our Zestimate guide shows where the models miss in Northern Virginia.
How do you adjust a comp for condition or a finished basement?
Line by line, and in the open. Each comparable is adjusted for the differences that matter: condition and updates, finished space such as a basement, lot, and location within the neighborhood. The adjustment grid is part of the analysis, so you can see exactly how each comp moved the supported range. If an agent will not show the grid, you are looking at a price opinion, not an analysis.
What was the median home price in Fairfax County, Arlington, and Alexandria in September 2026?
NVAR, using Bright MLS data as of October 12, 2026, reported September 2026 median sold prices of $749,750 in Fairfax County (897 closed sales), $655,000 in Arlington County (175 closed sales), and $660,000 in the City of Alexandria (143 closed sales). The NVAR region median was $744,950 across 1,250 closed sales. A median is the middle closing price for the month, so use it as market context and price your own home from its subdivision comparables.
Can I see a real example of a CMA before I hire an agent?
Yes. The worked example on this page is anonymized from a Cornerstone CMA prepared on October 26, 2026, from Bright MLS records for a detached home in Springfield, Fairfax County. Its three closed comparables, all in the same subdivision and matching the subject on bedrooms and above grade square feet, closed between $699,000 and $797,000 and averaged $762,000, and the subject home was listed at $749,900, inside that range. Ask any agent you interview to show you the same thing: the comparables, the concessions netted out, and how the asking price sits against the closed average.