Pull up a market snapshot for Kentfield next to one for Greenbrae this month and you will see two towns that share a border, a ferry commute, and a buyer pool telling completely different stories. Kentfield's most recent monthly figures show a median sale price of $2.4 million, down 32.3 percent from a year earlier, with price per square foot down 23.4 percent to $928. Greenbrae's first-half 2026 numbers show the opposite: sales activity up from 18 homes in the first half of 2025 to 25 in the first half of 2026, average sale price climbing to $2,525,000, and average price per square foot rising from $942 to $1,153 over the same stretch.
If you are cross-shopping these two towns, that split looks like a real signal. One market cooling fast, one heating up fast, right next door to each other. It is not. It is what happens when you measure a handful of house sales with the same statistical tools built for markets that close hundreds of transactions a month.
Two Reports, One Zip Code Border
Kentfield and Greenbrae sit close enough that many buyers treat them as interchangeable options within the same central Marin search, both feeding into the Kentfield School District catchment and both a short drive from the Larkspur Landing ferry terminal. So when the headline numbers diverge this hard, it is worth asking what is actually being measured.
The Kentfield figure comes from a monthly median of closed sales. In a town where only a handful of homes change hands in any given month, the median is simply whichever house happened to be in the middle of that small stack. Swap out one $6 million estate sale for one $1.8 million cottage sale and the median moves by hundreds of thousands of dollars without a single home in town actually losing value.
Greenbrae's figures come from a six-month rollup rather than a single month, which smooths some of that noise but does not eliminate it. Twenty-five sales across half a year averages out to roughly four closings a month. That is still a thin enough sample that one unusually large or unusually modest sale can pull the average meaningfully in either direction.
The Same Contradiction Shows Up Inside Greenbrae Itself
You do not even need to leave Greenbrae to see this effect. One March 2026 snapshot of the town showed a typical home value of $1,750,000, down 2.8 percent year over year, with sales that month splitting evenly: 33 percent closed above list price and 33 percent closed below it, a profile that reads as a balanced, unremarkable market.
Widen the lens to the full first half of 2026 and the picture changes. Across the six months, 48 percent of all Greenbrae sales closed above asking price, at an average premium of 11.4 percent, and more than half of all transactions drew multiple offers, nearly double the rate from the prior period. Same town, same general window, two very different competitive pictures depending on whether you are looking at one month or a full half year.
That gap matters for how you read any market report a portal hands you. A single month in a market this size is a snapshot of whichever few houses happened to close, not a verdict on the town's direction. The six-month view is closer to a trend, and even that can shift again once the next batch of large or small sales rolls through.
What Zillow's Index Sees That Redfin's Median Misses
There is a second layer to this, and it shows up clearly in Kentfield's numbers specifically. Redfin's raw median put Kentfield's price decline at 32.3 percent year over year. A separately calculated home-value index for the same market and the same rough period put the decline at just 9.7 percent.
Both numbers are describing the same town in the same window. The difference is methodology. A raw median of closed sales reacts instantly and fully to whatever handful of houses sold that month. A smoothed valuation index is built to filter out exactly that kind of noise by weighting repeat sales and broader trends rather than treating each month's small sample as gospel. Neither approach is wrong. They are answering slightly different questions, and a 22-point gap between them on the same market is your clearest signal that you are looking at a town too small for either number to be trusted on its own.
So Is Greenbrae Actually Outperforming Kentfield Right Now?
The honest answer is that the two markets are not comparable on the metrics currently making headlines, and that is the whole point. Here is what each town's numbers actually support when you set the single-month noise aside:
| Metric | Kentfield | Greenbrae |
|---|---|---|
| Reported price direction | Down sharply on raw median, down modestly on smoothed index | Up on both average price and price per square foot, H1 2026 vs H1 2025 |
| Price per square foot | $928, reported down 23.4% YoY | $1,153, up from $942 the prior half |
| Competition signal | Not clearly reported at this sample size | 48% of H1 2026 sales above list, avg. 11.4% premium, multiple offers on more than half |
| What the number is really measuring | A handful of monthly closings | A six-month rollup, still a small sample |
Greenbrae's six-month trend is the more trustworthy read of the two, simply because it covers more transactions. The rising price per square foot and the jump in over-asking sales point to genuine buyer competition, not a statistical accident. Kentfield's picture is muddier. A 32 percent median swing in a market this size almost certainly overstates whatever real shift happened, and the calmer 9.7 percent index figure is probably closer to the truth, though even that number should be treated as a rough estimate rather than a precise read on any specific home's value.
None of this means Kentfield is secretly cheap or that Greenbrae is secretly overheated. It means the headline percentage on either town tells you less than you think, and the only way to actually compare them is to look past the topline number.
How To Actually Compare These Two Towns Before You Write An Offer
If you are deciding between a Greenbrae listing and a Kentfield listing this season, a few habits will serve you better than trusting whatever median a portal surfaces first.
Ask how many sales sit behind any percentage you are shown. A trend built on four or five closings deserves far more skepticism than one built on twenty-five. Look at price per square foot across at least two consecutive periods rather than one, since a single month can be skewed by a single unusual property on either end. Watch the percent-over-asking and multiple-offer figures as your real read on competition, since those tend to move more gradually and reflect actual buyer behavior rather than which specific houses happened to close. And when a town's numbers look dramatically different from its neighbor's, treat that gap as a prompt to pull the actual list of recent comparable sales rather than a conclusion in itself.
That last step is where local, transaction-level knowledge does the work that a dashboard cannot. Knowing which specific Kentfield sale pulled that median down, or which Greenbrae streets are driving the price-per-square-foot gain, turns a confusing headline into an actual answer.
FAQ
If Kentfield's median price is really down 32 percent, is now a good time to buy there? Treat that number as a starting question, not an answer. A decline that large in a market with only a few monthly sales is more likely to reflect which specific homes closed than a genuine repricing of the town. The smoothed valuation index for the same period showed a much smaller decline, which is probably closer to the real trend, but confirming that requires looking at actual comparable sales rather than the headline percentage.
Does Greenbrae's stronger first-half report mean sellers there should expect the same result for the rest of 2026? Not necessarily. The first-half 2026 numbers reflect real buyer competition, but they are still built on a small enough sample that the second half could look different depending on what comes to market. A strong six-month trend is a better signal than a single strong month, though it is not a guarantee that carries forward automatically.
Is there a town size where these median swings stop being a problem? Generally yes. Markets with a few hundred closings a year, like broader San Rafael, produce much steadier month-to-month medians simply because a single unusual sale gets diluted across a bigger pool. In towns the size of Kentfield or Greenbrae, that dilution does not exist, which is exactly why any single month's headline number needs a second look before you act on it.
If you are weighing Greenbrae, Kentfield, or another central Marin option and want someone to pull the actual comparable sales behind these numbers rather than the headline percentage, Carla Giustino has spent more than 25 years reading this exact stretch of market. Request a complimentary Marin market consultation before you write your next offer.
