Zestimate shows our home 30,000 less than the county has assessed it, why are they so high?

Dear Mr Trevor:

You wrote  "they would run such an incorrect appraisal of my property"  Please note, a Zestimate is not an appraisal and should never substitute for an appraisal.  You can read more in the Zillow FAQs.

Note 2:   Usually responding to questions of the last week or two, or perhaps as old as two or three months can add value.   Dredging up posts from a year or more ago (in this case Aug 2009), does not add value but suggests you are just posting to inflate your posting record.

I am finding Zestimates not at all useful for the ACTUAL value of any one property.  They can be generally useful for overall pricing of an area and the relative ups and downs of an area over a long time, but can be way off on specific properties which may have recent updates or special ammenities.  I mean it's an automated evaluation which no matter how clever they say the algorithm is, simply averages prices for a large geographic swath. Its a good example why live, licensed agents are worth the extra money instead of just using free internet apps.  Rule of Acquisition #59: Free advice is seldom cheap.

But there is also the possibility that you assessor's valuation was never adjusted for the real estate decline and that you should appeal the valuation.  Lots of people do that with less evidence.

I ran a listing ad on Zillow for new construction which, because it was newer and larger than the nearby homes, was a fair amount more expensive.  Zillow sort of undersold me and put a Zestimate tens of thousands less than our asking price, which did not make me want to advertise with them when they would run such an incorrect appraisal of my property.  The valuation would have been right if my house had been 20 years old with a bad roof and less floor space, but it was way off for the house that was to be built.