I had a conversation recently with a home owner about the online valuation site Zillow, and it went like this:
Owner: Your value was right on.
Me: Wonderful. That’s great to hear.
Owner: It was right in line with Zillow.
Me: Oh, okay.
This conversation made me smile since like many consumers, the property owner thinks of Zillow as the standard for accuracy. After all, Zillow is a very well-known brand that is becoming a household name. Heck, even President Obama used Zillow to moderate a conversation on housing a few months ago. We still need to ask the question though, how reliable is Zillow? Let’s take a look at 10 recent actual appraisals compared with “Zestimates”. I would be curious to hear your take too – especially if you’ve had a recent appraisal. How much of a value difference was there between the “human” (appraiser) and “machine” (Zillow)?
- Tahoe Park Area House: Appraisal: $133,000; Zillow: $114,173 (-14%)
- Del Paso Manor House: Appraisal: $332,000; Zillow: $305,000 (-8.1%)
- Midtown Fixer: Appraisal: $130,000; Zillow: $203,000 (+56%)
- Citrus Heights House: Appraisal: $278,000; Zillow: $240,000 (-13.7 %)
- Citrus Heights House: Appraisal: $138,000; Zillow: $194,000 (+40.6%)
- College Greens House: Appraisal: $259,000; Zillow: $282,000 (+8.9%)
- Fair Oaks House: Appraisal: $630,000; Zillow: $612,000 (-2.8%)
- Galt House: Appraisal: $191,000; Zillow: $188,000 (+1.5%)
- Mather House: Appraisal: $255,000; Zillow: $238,000 (-6.7%)
- Capital Village House: Appraisal: $233,000; Zillow: $191,000 (-18%)

Appraisals vs. Zestimates: First off, I am not anti-Zillow since I believe there is a place for Zillow in today’s world. I’m actually a fan of their graphs, rental estimates, neighborhood information and the power of their brand. Ultimately I tend to give little weight to “Zestimates” for the following four reasons:
- Condition: Zillow has no idea about condition or upgrades. This often makes an enormous difference in value (obviously).
- Knowing the Niche: It is very challenging for Zillow to capture the idiosyncracies of niche areas that fetch higher or lower prices for whatever reason.
- Margin of Error: Zillow posts their margin of error, and it shows they are off by quite a bit (click the link). Of course to be fair, appraisers can be off too.
- Distressed Sales: I’ve noticed at times Zillow struggles to see beyond distressed sales. For instance, the vast majority of sales in Capital Village (#10) have been short sales recently that sold for too little, and Zillow was unable to interpret true market value around $220,000 to 230,000 compared to all the distressed data points around $190,000.
Question: Any thoughts, insight or stories to share? I’d love to hear your take.
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Owner: Your value was right on.
Is Zillow accurate? It’s hit and miss. Ultimately I don’t consider Zillow to be reliable. As you can see above, some of the values were really close, but others were not close at all. An online valuation site cannot possibly know the idiosyncrasies of a real estate market – not to mention interior condition, level of charm or quality of updates either. Sometimes tract neighborhoods with a high level of data seem to have more accuracy on Zillow (not always true), while neighborhoods where each street and house are different can be very far off (even hundreds of thousands of dollars off the mark). For instance, in Yolo County data can be very sparse, so an online “valuation” without actual data isn’t all that compelling. I would say if you use Zillow regularly, use it for what it’s worth, but understand its limitations.
else has sold at $350,000, the lower sale is probably more of an outlier than anything. This one “lone ranger” doesn’t establish the trend of values in the neighborhood or trump all other sales either because it’s not consistent with the rest of the data (even if it’s the most recent sale). This assumes of course there has been no big issue to cause a dramatic decline in property value. On the other end, just because one sale closed $50,000 higher than everything else does not mean the market is now willing to accept all other properties at that level either. Outliers can be on the low end and high end of the market.
Distressed sales: It’s important to sift through distressed inventory because these sales tend to close at lower levels.