How Accurate are Zillow's Zestimates? Here Are the Facts!

Real Estate Agent with Asset Realty Group

My clients are always telling me what they think their house is worth, and come to find out, they most often cite the Zillow Zestimate value they saw online.  I don't know about you, but in the last 30 days, I have seen Zestimate drops of up to 9% in one month!  Now that's crazy, no house changes price that fast, this isn't the stock market! 

Now they don't just pull these values out of nowhere, they are using automated valuation appraisal methods that aggregate enormous amounts of data continuously to come up with a specific home's Zestimate. 

Zillow Zestimates don't take into account how a particular home is improved, or the condition of that home.  Their program cannot evaluate views or street noise, or any number of the idiosyncracies that can swing a property's value one direction or the other.  They readily admit that the accuracy of their Zestimates is only within 5% of the sales price 34% of the time in King County, WA. 

They are within 10% of the sales price 58% of the time, and within 20% just 82% of the time. The accuracy figures for Pierce and Snohomish Counties are pretty similar to King County.  Zillow's accuracy figures vary by county and they track 99% of the homes in the market. 

As much as our market conditons have changed in the last 4 years, it has been a more challenging task to place correct value on a property.  We are up to that task, call on us if we can help unscramble some of the confusion!



Comments (5)

Lee Ann Monfredini
Lee Ann Monfredini at Compass Real Estate San Francisco - San Francisco, CA

I completely agree with you-their estimates are flat and are so unaware of neighborhood flavor and known good blocks in the area. Thank you for posting.

Feb 11, 2011 10:26 AM
Kevin Simshauser
Keller Williams Realty | Newport Estates - Newport Beach, CA

ZILLOW is a nightmare, people think their iphone app is a genius.  I will use these statistics in the future.  Thank you!!!

Feb 11, 2011 10:26 AM
Tamara Elliott-Deering
Central Metro Realty - Austin, TX


If only are job was as easy as punching an address into Zillow and getting the value, even if it were I'm not sure our clients would believe us.


Feb 11, 2011 10:40 AM
Clark Cook
1st Choice Realty of Fayetteville, LLC - Fayetteville, NC
Marketing Homes For Sale In Fayetteville NC Area

Every lender I have used requires an appraisal! So much for estimates and zestimates! We do a better job with CMA's than Zillow.

Feb 11, 2011 10:44 AM
Kate Bourland
Marketing with Kate - Redding, CA
Onlilne Marketing Mobile Marketing

Zillow is one of those authority sites that seems to get facts wrong.  It's nutty.

Feb 12, 2011 04:25 PM