Selling
How Accurate Is a Zestimate for a Brentwood Home?
Zillow says its off-market estimates miss by about 8% at the median in the San Francisco metro. What that means on a Brentwood price, and what the models can't see.
You type your address into Zillow, a number comes back, and it either makes your day or ruins it. Then the question: is that what my house is worth? Zillow publishes its own answer to how close that number usually lands, and for our part of the Bay Area it's wider than most people expect.
For homes that aren't for sale, Zillow's own figures show a median miss of about 8% in the San Francisco metro, the closest breakout it offers to Brentwood. On a $750,000 home, that's roughly $60,000 either way. Only about a third of those estimates land within 5% of the eventual sale price.
Zillow's accuracy figures, September 30, 2026 refresh
- Nationwide, homes not for sale: 7.20% median error
- Nationwide, homes listed for sale: 1.77% median error
- San Francisco metro, not for sale: 8.04% median error, with 34.04% landing within 5% of the sale price
What a median error means on your price
A median error is the middle of the pack, not the worst case. Half of the estimates miss by less than that figure, and half miss by more.
Zillow doesn't publish a Brentwood number. Its nearest breakout is the San Francisco metro, a big area that runs from the coast out to the Delta. One model is stretched across very different towns.
Zillow also refreshes these figures every month, so the exact percentages will move. The shape of the answer doesn't change much: in our metro, a lot of off-market estimates miss by more than 5%, and some miss by a good deal more.
Listed homes get the accurate version
Zillow's figure for homes that are listed for sale is much tighter. Redfin shows the same split for its own estimate. Both say the reason is the listing itself: once a home is on the market, the model can see the list price, the details, and how buyers are responding.
That's the catch for a seller. The accurate version shows up after you've already picked a list price, and it leans on the price you picked. The number you see while you're still deciding is the off-market one, the one that misses by more.
What the models can't see on a Brentwood street
Zillow says its model draws on an area much larger than your neighborhood, "up to the size of a county." Here's what a model working at that scale has trouble pricing here:
- Trilogy's 55+ status. Trilogy at the Vineyards is an age-restricted community, so its buyer pool is different from a same-size home a mile away. The 55+ rules post covers how that works.
- Mello-Roos boundaries. Two similar homes can carry different special taxes. A buyer looks at the monthly cost. A model reading bedrooms and square footage doesn't. More in Mello-Roos, explained.
- Owned versus leased solar. Owned panels go with the house; a lease comes with paperwork the buyer has to accept. I walk through it in selling a home with solar.
- The lot. Lot size is in the record. Whether it backs to open farmland, a busy road, or a fairway usually isn't.
- Work the county never saw. Zillow says this one itself: additions, updates, and remodels that weren't reported to the assessor aren't reflected in the Zestimate.
What escrow taught me about sale prices
I worked in lending, title, and escrow before I ever listed a house, and one thing from those years shapes how I read any automated value.
A sale price doesn't always tell you what the seller walked away with. If a buyer asks for a repair credit after inspections and it's handled as a closing credit instead of a price cut, the sale price can stay where it was. On paper it looks like a full-price sale. The seller netted less.
A few of those on one street in a soft month, and the comparable sales look stronger than they were. A model reading sale prices has no way to know. Someone who has read the closing statements does.
Curious how far off your own estimate is? Send me your address and I'll put my comparable-sales number next to Zillow's and show you where they part ways. Call or text (925) 200-0717. I pick up myself.
This post is general information, not an appraisal or legal or tax advice. Online estimate accuracy figures change with each refresh; check Zillow's and Redfin's pages for the current numbers. For a value on a specific home, ask for a comparative market analysis or a licensed appraisal.
Margie Lupo, Broker Associate, SRES® · eXp Realty of Northern California, Inc. · DRE #01193496 · Brokerage DRE #02188495 · Equal Housing Opportunity
Sources
- Zillow, "What's a Zestimate?" — accuracy by region, methodology, and limits
- Redfin, "About the Redfin Estimate" — Redfin's on- and off-market accuracy
Frequently asked questions
Is a Zestimate an appraisal?
No. Zillow says the Zestimate isn't an appraisal and can't be used in place of one, and that most lenders rely on professional appraisals for loan decisions.
Can an agent change my Zestimate?
No. Zillow says it's not possible to manually alter a Zestimate, and Redfin says its estimate is calculated by computers. What an owner can do is correct the home facts, like square footage and bedroom count, and report finished work to the county assessor.
Should I list at my Zestimate?
I wouldn't. In our metro, most off-market estimates miss the eventual sale price by more than 5%. Pricing is a decision about your street, your floor plan, and what you're competing with that month.
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